file name: amazing science tg-08 1st proof: 27-10-2010
TRANSCRIPT
i 1
File Name: Amazing Science TG-08 1st proof: 27-10-2010 --------------------------------------------------------------------- Received Ist print out 24-11-10 AJ2nd, Ist print out hand over to AJ 26-11-10 TK --------------------------------------------------------------------------------- Received 2nd print out 29-11-10 AJ3rd, Ist print out hand over to AJ 30-11-10 TK
iii 1
ContentsIntroduction......................................................................................................................... iv
Unit 1 Structure of living organisms ...........................................................................1 Lesson plans ........................................................................................................ 5 Worksheets ........................................................................................................... 9
Unit 2 Organ systems in human beings ....................................................................11 Lesson plans ....................................................................................................... 14 Worksheets .......................................................................................................... 17
Unit 3 Transport systems in plants and animals ......................................................19 Lesson plans ....................................................................................................... 23 Worksheets .......................................................................................................... 27
Unit 4 Growth and reproduction in living organisms ............................................ 29 Lesson plans ....................................................................................................... 33 Worksheets .......................................................................................................... 36
Test paper 1 ............................................................................................................................38
Unit 5 Living organisms and their environment .................................................... 40 Lesson plans ....................................................................................................... 44 Worksheets .......................................................................................................... 49
Unit 6 Water ................................................................................................................. 51 Lesson plans ....................................................................................................... 55 Worksheets .......................................................................................................... 59
Unit 7 Composition of matter .................................................................................. 61 Lesson plans ....................................................................................................... 66 Worksheets .......................................................................................................... 70
Unit 8 Changes in matter .......................................................................................... 72 Lesson plans ....................................................................................................... 76 Worksheets .......................................................................................................... 81
Test paper 2 ............................................................................................................................83
Unit 9 Heat and energy .............................................................................................. 85 Lesson plans ....................................................................................................... 90 Worksheets .......................................................................................................... 95
Unit 10 Dispersion of light ......................................................................................... 97 Lesson plans ..................................................................................................... 101 Worksheets ........................................................................................................ 104
Unit 11 Oscillations and waves .................................................................................. 106 Lesson plans ..................................................................................................... 110 Worksheets ........................................................................................................ 114
Unit 12 Current electricity ......................................................................................... 116 Lesson plans ..................................................................................................... 119 Worksheets ........................................................................................................ 125
Unit 13 Investigating space ......................................................................................... 127 Lesson plans ..................................................................................................... 131 Worksheets ........................................................................................................ 133
Test paper 3 ..........................................................................................................................135
iv1
IntroductionScience and technology have assumed great importance in the world today. Not only has science changed our life, it has also influenced our thinking. We have used scientific knowledge to raise our standard of living and develop a better relationship with nature.
The study of science develops a spirit of enquiry that enables the scientist to understand the interrelationships that exist in nature. A student of science develops the habit of observing carefully, and collecting data accurately so that scientific phenomena can be seen in their true perspective. This habit not only develops a scientific attitude but also inculcates critical thinking that helps in drawing conclusive results from observations. Thus it enables a student of science to better understand and appreciate the environment as a whole.
The subject of science has always been considered a learning subject at the school level and the student has to go through a rigorous exercise of learning it by heart in order to pass examinations. In reality, science is not a subject to be memorized; it has to be given serious thought and this makes it a difficult subject. But if science is taught in such a manner that students understand its true meaning and develop a scientific approach towards understanding scientific phenomena, its study becomes meaningful as well as interesting.
A teacher can play a very important role in arousing the interest of students by allowing them to discuss facts and ideas and helping them to draw conclusions from them as to why and how things happen.
The teacher can stimulate the thinking process of students by asking questions and also by encouraging them to ask questions. Experimental work enables students to test for themselves the facts that have been learnt by them, thereby making it easier for them to understand the implications of the background to their activities.
This course has been developed to provide information about the world around on which students can base their opinion, verify information, come to conclusions, and use the knowledge thus gained in their everyday life. It will help in maintaining the curiosity and enthusiasm of students who have just started studying science. Concepts developed at this stage will be of use in their studies at an advanced level later. It will help them to develop a better outlook of life. In order to control the learning process the teacher not only encourages and advises but also critically evaluates the work of the students.
About the Pupil’s Book:This science series has been written especially for children both at the primary and secondary levels. It provides information at a child’s level of understanding and has a direct appeal for children who need interesting and easy to read material.
Keeping in view the interests, abilities, curiosities, and needs of children, it provides stimulating learning experience and offers enjoyable educational motivation, thus serving as a building block for further learning.
The keyword in science is curiosity. The material in the series is designed to awaken in a child the same urge that motivates a scientist; the desire to know the answer to a question. There is a wide range of topics that will interest and motivate the child.
v 1
Teachers will recognize that it deals with those broad areas about which most children frequently express curiosity; that it provides answers to many questions they ask, offering new and exciting information on many fields. It aims to create an awareness, as well as stimulate an interest in science.
The language is simple and easy to read and within the grasp of the students’ abilities of each grade. Together, the text and illustrations motivate children to discuss, question, and explore.
The contents have been selected and are presented in such a way as to capture and hold the interest of the students. The objective is to simplify complex ideas and present them in an interesting way. Every effort has been made to keep the language simple.
When it is necessary to use a specialized word, it has been gently introduced into the text. When it is not self-explanatory within the context, it is defined. Clear and well-labelled illustrations have been included, which help to identify and clarify the topics dealt within.
Good pictures and diagrams arouse and develop interest. These make lasting impressions. They help to make the text clear. They also appeal to the child’s imagination, while satisfying his/her curiosity and often provoke a favourable reaction.
Simple practicals—interesting and stimulating presentation of factual materials—offer every chance of successful learning experiences. Knowledge of problem-solving techniques so acquired can be applied in everyday life.
It is intended, through this series, to introduce children to many of the interesting and enjoyable things they can learn about and do for themselves. Also to develop in them the quest for knowledge and understanding of how science is shaping the world in which they live.
Syllabus break-up:The textbook has been divided into four parts, namely biology, chemistry, physics, and the Earth and universe. Each chapter of the Teaching Guide pertains to the topics discussed in the textbook. This makes the work of the teacher easier.
In most schools the school year is roughly divided into three terms, i.e. Spring, Summer, and Winter. It is up to the teacher to select the topics to be taught in each term, but this selection should be well-balanced as sometimes a teacher would prefer to teach the topics that are easier or are better liked by him or her than others. For instance, a biology teacher would prefer to teach biology first and neglect the other parts.
To overcome these problems, each part of the textbook has been written in such a way that each topic is self-explanatory and the answers to the questions at the end of each chapter can be readily found in the text. Definitions and all aspects of each topic have been highlighted for quick reference, and simple experiments have been given wherever possible to make the concepts clear as well as make learning interesting and easy.
The role of the teacher:It is up to the teacher to devise means and ways of reaching out to the students, so that they have a thorough knowledge of the subject without getting bored.
The teacher must use his/her own discretion in teaching a topic in a way that he/she finds appropriate, depending on the intelligence level as well as the academic standard of the class.
Introduction
vi1
To the teacher:With your assurance and guidance the child can sharpen his skills.
Encourage the child to share his experiences. Try to relate to real things. Do not rush the reading. Allow time to respond to questions and to discuss pictures or particular passages. It will enhance learning opportunities and will enable the child to interpret and explain things in his/her own way.
Preparation by the teacher:Be well-prepared before coming to class.
i) Read the lesson. ii) Prepare a chart if necessary. iii) Practise diagrams which have to be drawn on the board. iv) Collect all material relevant to the topic. v) Prepare short questions. vi) Prepare homework, tests, and assignments. vii) Prepare a practical demonstration.
The following may also be arranged from time to time.
i) Field trips ii) Visits to the laboratory iii) A show of slides or films iv) Plan projects
Method of teaching:The following method can be employed in order to make the lesson interesting as well as informative.
The basic steps in teaching any science subject are:
i) locating the problem ii) finding a solution by observation and experimentation iii) evaluating the results iv) making a hypothesis and trying to explain it
The usual strategy which is easy as well as effective can be adopted:
i) Before starting a lesson, make a quick survey of the previous knowledge of the students by asking them questions pertaining to the topic, from everyday observation of their surroundings, or from things they have seen or read about in books, magazines, or newspapers.
ii) Explain the lesson. iii) Write difficult words and scientific terms on the board. iv) Ask students to repeat them. v) Help students to read text. vi) Show materials, models, or charts. vii) Make diagrams on the board.
Introduction
vii 1
viii) Perform an experiment if necessary. ix) Ask students to draw diagrams in their science manuals. x) Students should tackle objective questions independently. xi) Ask questions from the exercises. xii) Answers to questions to be written for homework. xiii) The lesson should be concluded with a review of the ideas and concepts that have been
developed or with the work that has been accomplished or discussed.
Starting the lesson:Before starting a lesson, the teacher should make a quick survey of the previous knowledge of the students by asking some questions pertaining to the topic from their everyday observation.
It is not necessary that the class should begin with the reading of the textbook. The lesson should begin with the teacher telling an interesting incident or information that will keep the students interested and make them want to know more about the topic which has been introduced. Each topic of the lesson should be explained thoroughly and to check whether students are following, short questions should be asked in between the lecture.
Making a sketch or diagram on the board is a very important aspect of the study of science but too much time should not be spent on it or the students lose interest. An alternative to drawing on the board is a ready-made chart, or one made by the teacher, which can be hung in the classroom. The use of visual material is very effective as it keeps the students interested as well as helps them to build mental pictures which are learnt quickly and can be recalled whenever needed. Students, too, take interest in drawing diagrams and they should be helped by the teacher when diagrams are being made in class. If a diagram is not in the textbook then the students should either copy it from the board or a chart, or the teacher should photocopy it and distribute among the students.
Practicals and experimental work:The science laboratory of any school should be well-equipped for meeting the requirements of the practical work done at the school level. The science teacher may make suggestions and request for material and equipment to perform simple experiments.
Science students should be taken to the laboratory to see the laboratory in charge at work. They can also see the specimens of various plants and animals on display and be introduced to some scientific equipment, chemicals, and solutions.
Practical work arouses interest in the subject. Some experiments can be easily performed in class. Class activities can be organized in such a way that the whole class can participate in and benefit from them. Students can be asked to work in groups or in pairs, depending on the type of work that is to be done, or the amount of material that is available. Demonstrations by the teacher are unnecessary. A clear sequence of instructions related to the activity should be given and the students should be allowed to work independently, but the teacher, should be in direct and immediate control of everything. Teachers should also determine the pace of work.
If there is any difficulty or danger encountered at the start of an experiment, or during it, the teacher should be prepared to improvise, and provide an alternative method, or a different experiment giving the same results.
Introduction
viii1
Most of the experimental work should be carried out by the students themselves, as it develops more interest and a sense of responsibility among the students. The basic method or technique should be thoroughly understood by the students before an experiment is performed. The students should be allowed to work independently under strict supervision. A record of the observations should be carefully made, preferably in tabular form. The conclusions or results should be thoroughly discussed in class before writing them down. Written work should be checked carefully and regular tests should be conducted. (Simple experiments have been given in each topic which will enable the teacher to plan and prepare them quickly and with ease.)
If the steps involved in the experiment and the precautions to be taken are explained clearly and thoroughly, the experiment can be successful and the students will develop a sense of achievement and confidence.
When the discussion of a topic has been completed, it should be summarized by the teacher along with the participation of the students by writing down all the important ideas and concepts that have developed from the text and the experimental work.
These guidelines for teachers will enable them to teach science effectively and develop in their students an interest in the subject which can be maintained throughout the academic year and possibly in their lives as a whole. These suggestions are not mandatory. They can only supplement and support the professional judgement of the teacher and in no way can they serve as a substitute for it.
Introduction
1 1
Teaching objectives:• to explain the structure and functions of the vegetative parts of a plant• to explain the structure and function of the reproductive parts of a plant• to study the basic structure of the body of an animal• to explain the importance, structure, and function of the skeleton• to describe the structure and function of different types of skeletons• to explain the importance, structure, and function of joints
Teaching strategy:
Structure of plantsPlace a complete flowering plant, a grass plant, and an onion bulb on the table. Show the students the onion. Ask if it is a plant. Hold up the flowering plant and the grass plant and show them the various parts. Ask: What is the difference between the onion and the flowering plant?
Peel the onion, remove the fleshy leaves and show them the stem and the roots. Pluck the leaves off the stem of the flowering plant and show them the nodes and internodes and the axillary buds. Explain that the leaves, branches, and flowers grow at the nodes. Show the stem tip and explain that it is the growing point of the stem. Explain the structure of the stem and ask them to compare it to the grass stem. Ask: What are the functions of the stem? Explain the stem as the part of the plant that bears all other parts of the plant and is a means of transporting food and water. Thick fleshy stems can also store food.
Show the roots of three plants. Ask: What is the difference between them? Explain the different kinds of root systems. Draw the microscopic structure of a root on the board and explain the function of each part. Explain the functions of roots.
Show students different kinds of leaves. Give them a leaf each and ask them to examine it carefully. Teach them to make a leaf print by placing a tracing paper on the leaf and rubbing it. Draw a leaf on the board and label its parts. Ask students to label their leaf prints. Ask: What are the functions of leaves? Explain the importance of leaves for plants. Explain why some leaves are thick, hairy, or spiny. Ask students to bring flowers to the class. Encourage them to examine the flowers carefully. Draw a flower on the board and label it. Explain the structure and function of each part. Explain the importance of the flower as the reproductive part of the plant. Explain the difference in structure of various flowers.
UNIT 1Structure of living organisms
21
Ask students to touch the centre of the flower. Explain what the yellow powder is. Draw a longitudinal section of a flower on the board. Label each part. Cut a longitudinal section of a flower and show the parts to the students with a hand lens. Ask students to dissect the flower with a forceps and stick each part with a pin in its correct place on a sheet of paper, and write the name of each part. Cut the cross section of the ovary of a flower and show the attachment of the ovules inside it.
Structure of animalsShow a model of a butterfly or a cockroach and a vertebrate animal to the students. Ask them to point out the differences between them. Explain the division of the body into parts.
Ask: Why are most of the sense organs located in the head region? Explain the importance of the brain and the central nervous system in controlling the whole body. Ask: What is the function of the trunk? Explain the attachment of the limbs which help to bring about movement and also how all the organs and body systems are located in the trunk region.
Explain the skeleton as an outer covering for insects and as a bony structure in vertebrates. Ask: Does an earthworm have a skeleton? Explain the types of skeletons and their functions. Show the model of a human skeleton or a preserved specimen of a rabbit or frog to the students. Explain the general plan of the skeleton in all vertebrates. Show the various types of bones and joints. Explain how the skeleton can perform its various functions. Explain the formation of joints and the types of movements that they can carry out.
Summarize the lesson.
Answers to Exercises in Unit 11. (a) The vegetative parts of a plant are stem, roots, and leaves. The reproductive parts of a plant
are flowers.
(b) The stem is the part of a plant which grows above the ground. It is usually erect and upright but some stems grow horizontally along the ground. Some stems are long, thin, and weak or they are thick and fleshy. Some stems grow underground and store food. Stems bear leaves, buds, flowers, and fruits. They also transport water from the roots to the leaves and prepared food from leaves to all parts of the plant.
(c) The different kinds of roots are: tap roots, fibrous roots, adventitious roots.
Some roots have one thick main root from which branch roots grow. Such roots, like carrots and radishes, are called tap roots.
In some plants, like grass, many branched roots of the same size grow out at the same time. Such roots are called fibrous roots.
Some roots, like the onion bulb, grow directly from the stem. These are called adventitious roots.
(d) The leaf manufactures food for the plant. Stomata in the leaves help in gaseous exchange. Some thick and fleshy leaves store food.
(e) The male reproductive part of the flower is called an androecium. It forms the third whorl. It is composed of stamens. Each stamen has a filament which is a thin stalk and an anther which is attached to the filament and contains four pollen sacs. The male sex cells are pollen grains which are produced inside the pollen sacs.
Unit 1 Structure of living organisms
3 1
The female reproductive part of the flower is called the gynoecium. It is composed of carpels. Each carpel is composed of an ovary, style, and stigma. Ovary which is the swollen basal part contains the female sex cells called ovules. The style is a thin stalk and the stigma which is the flat tip of the carpel, is sticky and receives the pollen grains during pollination.
(f) The hard material which supports and gives shape to the body of an animal is called skeleton. The types of skeleton are: hydrostatic skeleton, exoskeleton, and endoskeleton.
Some soft-bodied animals like earthworms and caterpillars do not have hard skeletons. Their bodies are supported by a liquid which is present in the cells and in the spaces between them. This type of a skeleton is called a hydrostatic skeleton.
An exoskeleton is found in most invertebrates. The bodies of insects are covered by a hard, tough skin or cuticle which is made of a strong, waterproof material called chitin. The cuticle is composed of plates and hollow tubes which not only protect and support the body, but also give it a specific shape.
Movement is brought about by muscles which are attached to the inside of the exoskeleton.
All vertebrates are supported by a hard internal skeleton called the endoskeleton. The endoskeleton is made up of bones of different shapes and sizes. It grows with the body of the animal. It supports the body and gives it shape. It protects the internal organs and helps in the movement of the body. The long bones produce red and white blood cells.
2. A root fixes the plant firmly in the soil. It absorbs and mineral salts from the soil. It may store food.
The stem bears leaves, buds, flowers, and the fruit of a plant. It spaces out the leaves so that each leaf can get air and sunlight. It transports water from the roots to the leaves. The stem also transports prepared food from the leaves to all parts of the plant.
A leaf manufactures food for the plant by photosynthesis. Stomata in the leaf help in gaseous exchange. Some thick and fleshy leaves store food.
A flower helps to make fruits and seeds.
Sensory organs help the animal to detect changes in its surroundings and to react to them accordingly.
A skeleton helps to support and protect the internal organs of the body. It also helps to bring about movement.
3, 4, 5 Refer to Pupil’s Book.
Parts of body Description
head contains the mouth and the sensory organs
trunk contains the important organs and systems
exoskeleton is composed of plates and hollow tubes which protect and support the body
Amazing Science TG 7
41
cuticle gives shape and support s the body of animals
hydrostatic skeleton supports soft-bodied animals by a liquid present between the cells
endoskeleton made up of bones of different sizes and grows inside the body
moulting is the process when the cuticle is shed and a new one grows in its place
bones are hard and made up living cells and mineral substances
Additional Exercise
MCQs
(a) The stem, root, and leaves are the parts of a plant. vegetative reproductive characteristic [vegetative](b) The part of the plant that bears the leaves, buds, flowers, and fruits of the plant is
. Roots leaves stem [stem](c) The flat green part of the leaf is called . petiole midrib lamina [lamina](d) Flowers arranged in a group or cluster is called . spike inflorescence florets [inflorescence](e) Flowers of the wheat plant are arranged in an inflorescence called . floret spike florets [spike](f) The part of the animal body that contains the sensory organs is called . head trunk limbs [head](g) Which one of the following animals does not have a hard skeleton? rabbit squirrel jellyfish [jelly fish](h) A hydrostatic skeleton is made up of a . solid liquid gas [liquid](i) The body of an insect is covered by a hard, water-proof skin called . chitin cuticle wax [cuticle](j) The skeleton which forms the main axis of the body of a mammal is called . appendicular skeleton axial skeleton exoskeleton [axial skeleton]
Unit 1 Structure of living organisms
5 1
Uni
t: 1
Topi
c: S
truc
ture
of
livi
ng o
rgan
ism
s
Teac
hing
obj
ecti
ves
Lea
rnin
g ou
tcom
es
Stud
ents
sho
uld
be a
ble
to:
Res
ourc
es/M
ater
ials
Act
ivit
ies/
CW
/HW
1.
Stru
ctur
e of
a
flow
erin
g pl
ant
ve
geta
tive
part
s
•to
des
crib
e th
e st
ruct
ure
of th
e st
em,
the
root
, and
a le
af o
f a
flow
erin
g pl
ant
•to
exp
lain
the
func
tions
of t
he s
tem
, ro
ot, a
nd le
af o
f a
flow
erin
g pl
ant
•de
scri
be th
e st
em, t
he
root
, and
the
leaf
of a
flo
wer
ing
plan
t
•ex
plai
n th
e fu
nctio
n of
ea
ch
A fl
ower
ing
pot p
lant
, an
onio
n bu
lb, s
ome
pott
ed
gras
s, s
peci
men
s of
roo
ts,
stem
s an
d le
aves
, sl
ides
of s
tem
tip,
roo
t tip
TS
of le
af
Rea
ding
: p 2
, 3, 4
Act
ivity
: 3
CW
: Q1
(a)
(b)
Q
3
HW
: Q1
(c)
(d)
Key
wor
ds: v
eget
ativ
e pa
rt, r
epro
duct
ive
part
, ste
m, n
ode,
inte
rnod
e, s
tom
ata,
term
inal
bud
, axi
llary
bud
, roo
t tip
, roo
t cap
, roo
t ha
ir, t
apro
ot, f
ibro
us r
oot,
adve
ntiti
ous
root
, pet
iole
, lam
ina,
mid
rib,
vei
n, p
hoto
synt
hesi
sM
etho
d: P
lace
a c
ompl
ete
flow
erin
g pl
ant,
an o
nion
bul
b, a
nd a
gra
ss p
lant
on
the
tabl
e. S
how
the
stu
dent
s th
e on
ion
bulb
.A
sk: I
s th
is a
pla
nt?
Hol
d up
the
flow
erin
g pl
ant
and
the
gras
s pl
ant.
Des
crib
e th
e st
ruct
ure
of a
pla
nt a
nd e
xpla
in t
he
func
tions
of e
ach
part
. Exp
lain
tha
t th
e ro
ots,
ste
m, a
nd t
he le
aves
are
cal
led
the
vege
tativ
e pa
rts
of a
pla
nt.
Ask
: Wha
t is
the
diffe
renc
e be
twee
n th
e on
ion
bulb
and
the
flow
erin
g pl
ant?
Pee
l the
oni
on a
nd c
ut it
long
itudi
nally
. Sho
w th
e st
uden
ts th
e st
em, t
he g
row
ing
tip, a
nd th
e fle
shy
leav
es. W
ith a
han
d le
ns s
how
them
the
posi
tion
of th
e bu
ds a
t the
bas
e of
the
leav
es. A
lso
show
the
root
s gr
owin
g fr
om th
e ba
se o
f the
bul
b.Pl
uck
off t
he le
aves
of t
he fl
ower
ing
plan
t and
sho
w th
e st
uden
ts th
e no
des,
inte
rnod
es, a
nd th
e ax
illar
y bu
ds. E
xpla
in th
at th
e le
aves
, br
anch
es, a
nd fl
ower
s gr
ow fr
om th
e ax
illar
y bu
ds a
t the
nod
es. P
oint
out
the
stem
tip
and
expl
ain
that
it is
the
grow
ing
poin
t of t
he
stem
. Exp
lain
the
stru
ctur
e of
the
stem
. Ask
the
stud
ents
to c
ompa
re th
e flo
wer
ing
plan
t to
a gr
ass
plan
t and
to th
e on
ion
bulb
.A
sk: W
hat i
s th
e fu
nctio
n of
the
stem
? E
xpla
in th
at th
e st
em is
the
part
of t
he p
lant
that
bea
rs a
ll th
e ot
her
part
s an
d is
als
o a
mea
ns o
f tra
nspo
rtin
g fo
od a
nd w
ater
. Thi
ck, f
lesh
y st
ems
can
also
sto
re fo
od.
Show
the
stud
ents
the
root
s of
the
thre
e pl
ants
. Ask
: Wha
t is
the
diffe
renc
e be
twee
n th
em?
Des
crib
e th
e di
ffere
nt k
inds
of r
oot
syst
em. W
ith th
e he
lp o
f dia
gram
s, e
xpla
in th
e m
icro
scop
ic s
truc
ture
of t
he r
oot a
nd e
xpla
in th
e fu
nctio
n of
eac
h pa
rt. E
xpla
in th
e fu
nctio
ns o
f roo
ts.
Show
the
stud
ents
diff
eren
t kin
ds o
f lea
ves.
Giv
e ea
ch o
ne a
leaf
and
ask
them
to e
xam
ine
it ca
refu
lly. D
raw
a le
af o
n th
e bo
ard
and
labe
l its
par
ts. D
emon
stra
te h
ow to
mak
e le
af p
rint
s on
trac
ing
pape
r by
rub
bing
ove
r th
e le
af w
ith a
pen
cil.
Ask
the
stud
ents
to
labe
l the
par
ts o
f the
ir le
af p
rint
s. A
sk: W
hat i
s th
e fu
nctio
n of
a le
af?
Exp
lain
the
impo
rtan
ce o
f lea
ves
for
plan
ts. D
escr
ibe
diffe
rent
kin
ds o
f lea
ves
and
expl
ain
why
som
e le
aves
are
thic
k, o
r ha
ve h
air
or s
pine
s.
Dat
e:
Tim
e: 4
0 m
ins
Les
son
plan
61
Uni
t: 1
Topi
c: S
truc
ture
of
livi
ng o
rgan
ism
s
Teac
hing
obj
ecti
ves
Lea
rnin
g ou
tcom
es
Stud
ents
sho
uld
be a
ble
to:
Res
ourc
es/M
ater
ials
Act
ivit
ies/
CW
/HW
2.
Rep
rodu
ctiv
e pa
rts
•to
des
crib
e th
e st
ruct
ure
of a
flow
er
•to
dis
cuss
var
iatio
ns
in fl
ower
str
uctu
re
•de
scri
be th
e st
ruct
ure
of
a flo
wer
•ex
plai
n th
e va
riat
ions
in
the
stru
ctur
e of
flow
ers
Diff
eren
t kin
ds o
f flo
wer
s,ha
nd le
ns, f
orce
ps,
shee
ts o
f pap
er,
stra
ight
pin
s
Rea
ding
: p 4
, 5
Act
ivity
: 1
CW
: Q4
HW
: Q1
(e)
Key
wor
ds: r
epro
duct
ive
part
, inf
lore
scen
ce, w
horl
, rec
epta
cle,
ped
icel
, cal
yx, s
epal
, cor
olla
, pet
al, p
ollin
atio
n, a
ndro
eciu
m,
stam
en, f
ilam
ent,
polle
n gr
ain,
pol
len
sac,
gyn
oeci
un, c
arpe
l, ov
ary
styl
e, s
tigm
a, n
ecta
r, ne
ctar
ine,
ray
flor
et, d
isc
flore
t, sp
ike
Met
hod:
Ask
the
stud
ents
to b
ring
som
e flo
wer
s to
the
clas
s. A
sk th
em to
exa
min
e th
e flo
wer
s ca
refu
lly. D
raw
a fl
ower
on
the
boar
d an
d la
bel i
ts p
arts
. Exp
lain
the
stru
ctur
e an
d fu
nctio
n of
eac
h pa
rt. A
sk: W
hy d
oes
a pl
ant p
rodu
ce fl
ower
s? E
xpla
in th
at
the
flow
er is
the
repr
oduc
tive
part
of t
he p
lant
. It h
elps
to m
ake
seed
s w
hich
gro
w in
to n
ew p
lant
s.
Ask
the
stud
ents
to to
uch
the
cent
re o
f the
flow
er. E
xpla
in th
at th
e ye
llow
pow
der
on th
eir
finge
rs is
pol
len.
Dra
w th
e lo
ngitu
dina
l se
ctio
n of
a fl
ower
on
the
boar
d an
d la
bel i
t. C
ut a
long
itudi
nal s
ectio
n of
a fl
ower
and
sho
w th
e st
uden
ts it
s pa
rts
with
a h
and
lens
.
Ask
the
stud
ents
to d
raw
the
outli
ne o
f a fl
ower
on
a sh
eet o
f pap
er. T
ake
the
part
s of
the
flow
er a
part
with
a p
air
of fo
rcep
s an
d pi
n ea
ch p
art
in it
s co
rrec
t pla
ce o
n th
e sh
eet o
f pap
er a
nd w
rite
the
nam
e of
the
part
. Cut
a c
ross
sec
tion
of th
e ov
ary
of a
flow
er
and
poin
t out
the
atta
chm
ent o
f the
ovu
les
insi
de it
.
Show
the
stud
ents
diff
eren
t kin
ds o
f flo
wer
s su
ch a
s a
rose
, a s
unflo
wer
, a h
ibis
cus,
sw
eet p
ea, a
nd a
whe
at s
pike
. Exp
lain
the
diffe
renc
es in
thei
r st
ruct
ures
.
Dat
e:
Tim
e: 4
0 m
ins
Les
son
plan
7 1
Uni
t: 1
Topi
c: S
truc
ture
of
livi
ng o
rgan
ism
s
Teac
hing
obj
ecti
ves
Lea
rnin
g ou
tcom
es
Stud
ents
sho
uld
be a
ble
to:
Res
ourc
es/M
ater
ials
Act
ivit
ies/
CW
/HW
3.
Stru
ctur
e of
ani
mal
s•
to d
escr
ibe
the
basi
c st
ruct
ure
of th
e bo
dy
of a
nim
als
•to
des
crib
e ty
pes
of
skel
eton
•to
exp
lain
the
gene
ral
plan
of t
he s
kele
ton
•de
scri
be th
e ba
sic
stru
ctur
e of
the
body
of
anim
als
•de
scri
be d
iffer
ent t
ypes
of
ske
leto
n
•ex
plai
n th
e ge
nera
l pla
n of
the
skel
eton
Spec
imen
s of
an
ant,
a co
ckro
ach,
an
eart
hwor
m, a
rab
bit
skel
eton
, a m
odel
of a
hu
man
ske
leto
n an
d a
rabb
it sk
elet
on
Rea
ding
: p 6
, 7
Act
ivity
: 2
CW
: Q6
HW
: Q1
(f)
Q
2
Key
wor
ds: h
ead,
ant
erio
r, m
outh
, sen
sory
org
an, t
runk
, ske
leto
n, h
ydro
stat
ic s
kele
ton,
exo
skel
eton
, end
oske
leto
n, b
one,
axi
al
skel
eton
, app
endi
cula
r sk
elet
on
Met
hod:
Sho
w th
e st
uden
ts a
n an
t, a
cock
roac
h, a
n ea
rthw
orm
, and
the
mod
el o
f a r
abbi
t. A
sk th
em to
poi
nt o
ut th
e di
ffere
nces
. E
xpla
in th
e di
visi
on o
f the
bod
y in
to p
arts
. Ask
: Why
are
mos
t of t
he s
ense
org
ans
loca
ted
in th
e he
ad r
egio
n? E
xpla
in th
e po
sitio
n an
d im
port
ance
of t
he b
rain
and
the
nerv
ous
syst
em in
con
trol
ling
the
who
le b
ody.
Ask
: Wha
t is
the
func
tion
of th
e tr
unk?
Exp
lain
that
the
limbs
are
att
ache
d to
the
trun
k: th
ey h
elp
to b
ring
abo
ut m
ovem
ent.
All
the
orga
ns a
nd b
ody
syst
ems
are
loca
ted
in th
e tr
unk
regi
on o
f the
bod
y. E
xpla
in th
e im
port
ance
of t
he s
kele
ton
for
all a
nim
als.
Dis
cuss
the
kind
s of
ske
leto
n in
inse
cts
and
othe
r in
vert
ebra
tes,
and
in v
erte
brat
es.
Ask
: Doe
s th
e ea
rthw
orm
hav
e a
skel
eton
? E
xpla
in th
e di
ffere
nt ty
pes
of s
kele
ton
and
thei
r fu
nctio
ns. S
how
the
stud
ents
a r
abbi
t sk
elet
on a
nd th
e m
odel
of t
he h
uman
ske
leto
n. E
xpla
in th
e ge
nera
l pla
n of
the
skel
eton
in a
ll ve
rteb
rate
s, a
nd e
xpla
in th
at th
e ax
ial s
kele
ton
form
s th
e m
ain
axis
whi
le th
e ap
pend
icul
ar s
kele
ton
is a
ttac
hed
to th
e ax
ial s
kele
ton.
Dat
e:
Tim
e: 4
0 m
ins
Les
son
plan
81
Uni
t: 1
Topi
c: S
truc
ture
of
livi
ng o
rgan
ism
s
Teac
hing
obj
ecti
ves
Lea
rnin
g ou
tcom
es
Stud
ents
sho
uld
be a
ble
to:
Res
ourc
es/M
ater
ials
Act
ivit
ies/
CW
/HW
4.
Join
ts
•to
des
crib
e a
join
t
•to
des
crib
e th
e ty
pes
of jo
int
•ex
plai
n th
e im
port
ance
of
join
ts
•de
scri
be th
e st
ruct
ures
of
join
ts
•id
entif
y di
ffere
nt k
inds
of
join
t
A m
odel
of t
he h
uman
sk
elet
on, d
iagr
ams
of
diffe
rent
kin
ds o
f joi
nts
Rea
ding
: p 8
CW
: Q5
HW
: Nam
e th
e ty
pe
of jo
int:
a. h
ip jo
int
b. k
nee
join
t
c. a
nkle
join
t
d. s
kull
bone
s
e. b
etw
een
skul
l and
ba
ckbo
ne
Key
wor
ds: j
oint
, lig
amen
t, ca
rtila
ge, s
ynov
ial f
luid
, cap
sule
, ten
don
Met
hod:
Sho
w th
e st
uden
ts m
odel
s of
var
ious
type
s of
join
t and
exp
lain
the
type
of m
ovem
ent e
ach
join
t can
mak
e. E
xpla
in h
ow
mus
cles
hel
p bo
nes
to m
ove.
Des
crib
e a
typi
cal j
oint
with
the
help
of m
odel
s an
d ch
arts
. Exp
lain
the
func
tions
of e
ach
part
of a
jo
int.
Exp
lain
the
vari
ous
kind
s of
join
t and
whe
re th
ey a
re fo
und
in th
e sk
elet
on.
Dat
e:
Tim
e: 4
0 m
ins
Les
son
plan
9 1
Unit 1: Structure of living organisms Worksheet 1
Name: Date:
1. Write the name of the part that matches the description.
Description Name
a. the main body of the plant that is made up of roots, stem, and leaves
b. the reproductive part of the plant which makes seeds and fruits
c. swollen areas on the stem from where leaves and buds grow
d. tiny holes on the stems and leaves for the exchange of gases
e. a bud at the tip of the stem
f. the part of the root from where it increases in length
g. fine hair on the root which absorb water and salts from the soil
h. the flat green part of a leaf
i. the parts of a leaf which transport food and water
j. a group or a cluster of flowers
Photocopiable material
101
Unit 1: Structure of living organisms Worksheet 2
Name: Date:
1. On the diagram, label the parts of the joint and name the type of joint.
2. Where in the human skeleton would you find the following types of joint?
Type of joint Example
a. ball and socket joint ,
b. hinge joint ,
c. sliding joint ,
d. fixed joint
e. pivot joint
Photocopiable material
11 1
Teaching objectives:• to explain the functions of the digestive system• to describe the various parts of the digestive system and explain its working• to discuss the common disorders of the digestive system and the measures that can be taken to
prevent them• to explain what respiration is and describe the various parts of the respiratory system• to explain the mechanism of breathing• to explain the difference between respiration and breathing• to describe the common respiratory diseases, their causes, and preventive measures
Teaching strategy:Ask: What happens to the food that we eat? How does the meat that we eat make our flesh? Explain the process of digestion and the role of enzymes. Show the students a chart of the digestive system and explain the role of each part in the digestion of food. Ask: Why should we include fruits and vegetables in our diet? Discuss the different vitamins and minerals that we get from fruits and vegetables and the importance of dietary fibre. Discuss the disorders associated with eating unhealthy food.
Tell the students to take a deep breath with their hands on their ribs. Tell them to breathe out. Ask: What did you feel with your hands? Explain the breathing movements. Ask: Why do you breathe? Explain the process of respiration and gaseous exchange in the air sacs. Ask: Which gas do we breathe in? Which gas do we breathe out? How can you test the gas that we breathe out? Tell a student to breathe out into a beaker containing freshly prepared lime water with a drinking straw. Ask: What happens? Explain that the air we breathe out contains a lot of carbon dioxide which turns the lime water milky. Describe the respiratory system and the structure of an air sac with the help of charts and diagrams on the board. Explain the importance of respiration for all living things. Ask: What are the bad effects of smoking? How does smoking affect our health? Discuss the causes and effects of respiratory diseases.
Help the students perform the various activities.
Summarize the lesson.
Organ systems in human beings
UNIT 2
121
Answers to Activities2. (a) The balloons
(b) Oxygen is taken in and carbon dioxide is given out
(c) In the air sacs (alveoli)
(d) Food is oxidized in the cells and energy and carbon dioxide are released.
(e) Differences between respiration and burning:
Respiration releases energy more slowly than burning.
The rate of respiration can be controlled.
Respiration produces heat only.
Burning produces light as well as heat.
Answers to Exercises in Unit 21. Name the correct part of the digestive system:
(a) teeth (b) mouth (c) stomach (d) pancreas (e) liver (f) glands in the intestines (g) large intestine (h) anus (i) villi
2. (a) Respiration is the process by which food is broken down, or oxidized in the body to release energy (b) oxygen (c) carbon dioxide (d) alveoli (e) rib cage (f) breathing takes place in living organisms. It releases energy slowly. The rate of respiration can
be controlled. It produces only heat.
3. Arranging the activities in the correct sequence:
The diaphragm contracts.
The intercostal muscles contract.
The chest gets larger.
Air is forced into the lungs.
The diaphragm relaxes.
The intercostal muscles relax.
The chest gets smaller.
Air is forced out of the lungs.
4. Label the parts of the respiratory system.
Refer to Pupil’s Book.
Unit 2 Organ systems in human beings
13 1
Additional Exercise
MCQs
(a) The breaking down of food into liquid form is called . digestion respiration excretion [digestion]
(b) The digestion of food in humans takes place inside a long tube called . excretory canal alimentary canal respiratory canal [alimentary canal]
(c) Enzymes in the gastric juice in the stomach help to digest . proteins fats carbohydrates [proteins]
(d) Bile is produced in the . stomach intestines liver [liver]
(e) Digested food is absorbed into the blood by finger like projections called . tubes villi capillaries [villi]
(f) Water from the undigested food is absorbed in the . colon small intestine kidney [colon]
(g) The process by which food is oxidized to release energy is called . digestion excretion respiration [respiration]
(h) Exchange of gases in the body takes place in the . lungs kidneys stomach [lungs]
(i) Excess animal fat in the diet leads to the formation of . cholesterol proteins vitamins [cholesterol]
(j) Many respiratory diseases like emphysema are caused by . sleeping eating smoking [smoking]
Amazing Science TG 7
141
Uni
t: 2
Topi
c: O
rgan
sys
tem
s in
hum
an b
eing
s
Teac
hing
obj
ecti
ves
Lea
rnin
g ou
tcom
es
Stud
ents
sho
uld
be a
ble
to:
Res
ourc
es/M
ater
ials
Act
ivit
ies/
CW
/HW
1.
The
dig
estiv
e sy
stem
•
to d
escr
ibe
the
part
s if
the
dige
stiv
e sy
stem
•to
exp
lain
the
func
tions
of e
ach
part
•de
scri
be th
e di
gest
ive
syst
em
•ex
plai
n th
e fu
nctio
ns o
f ea
ch p
art
Dia
gram
s of
the
dige
stiv
e sy
stem
, st
omac
h, v
illus
Rea
ding
: p 1
3, 1
4
CW
: Q1
HW
: Q4
Key
wor
ds: d
iges
tion,
alim
enta
ry c
anal
, enz
yme,
toot
h, s
aliv
a, s
aliv
ary
glan
d, to
ngue
, gul
let,
stom
ach,
gas
tric
juic
e, a
cid,
sm
all
inte
stin
e, p
ancr
eas,
pan
crea
tic ju
ice,
bile
, liv
er, i
ntes
tinal
juic
e, v
illi
Met
hod:
Sta
rt th
e le
sson
by
aski
ng: W
hat d
iffer
ent k
inds
of f
ood
do w
e ea
t? W
hat h
appe
ns to
the
food
that
we
eat?
Wha
t is
dige
stio
n? W
here
doe
s th
e di
gest
ion
of fo
od s
tart
? Whe
re d
oes
it en
d? W
hat h
appe
ns to
the
dige
sted
food
? Wha
t hap
pens
to th
e un
dige
sted
food
?
Show
the
stud
ents
a c
hart
of t
he d
iges
tive
syst
em a
nd d
escr
ibe
each
par
t. E
xpla
in th
e fu
nctio
n of
eac
h pa
rt. A
sk: W
hat i
s th
e ro
le
of th
e di
gest
ive
juic
es? W
rite
the
dige
stiv
e pr
oces
s in
the
form
of a
tabl
e:
Par
t of t
he d
iges
tive
sys
tem
T
he d
iges
tive
juic
e Ty
pe o
f foo
d it
act
s up
on
End
pro
duct
Ask
the
stud
ents
to fi
ll in
the
tabl
e af
ter
stud
ying
the
dige
stiv
e sy
stem
.
Dat
e:
Tim
e: 4
0 m
ins
Les
son
plan
15 1
Uni
t: 2
Topi
c: O
rgan
sys
tem
s in
hum
an b
eing
s
Teac
hing
obj
ecti
ves
Lea
rnin
g ou
tcom
es
Stud
ents
sho
uld
be a
ble
to:
Res
ourc
es/M
ater
ials
Act
ivit
ies/
CW
/HW
2.
Food
and
hea
lth•
to d
iscu
ss th
e im
port
ance
of f
ood
for
heal
th
•to
def
ine
diet
ary
fibre
and
exp
lain
its
impo
rtan
ce
•to
dis
cuss
som
e di
sord
ers
of th
e di
gest
ive
syst
em
•ex
plai
n ho
w e
atin
g to
o lit
tle o
r to
o m
uch
affe
cts
our
heal
th
•ex
plai
n th
e im
port
ance
of
die
tary
fibr
e in
our
di
et
•de
scri
be s
ome
dige
stiv
e di
sord
ers
A c
hart
of h
ealth
y an
d un
heal
thy
food
s,
pict
ures
of p
eopl
e w
ith
diet
pro
blem
s
Rea
ding
: p 1
4
CW
: 1. W
hat i
s th
e im
port
ance
of
diet
ary
fibre
in o
ur
diet
?
2. W
hat a
re th
e ba
d ef
fect
s of
eat
ing
the
wro
ng k
inds
of f
ood?
3. W
hat a
re th
e ca
uses
of
a. i
ndig
estio
n?
b. u
lcer
s?
Key
wor
ds: o
besi
ty, c
hole
ster
ol, t
ooth
dec
ay, h
igh
bloo
d pr
essu
re, r
ough
age,
fibr
e, in
dige
stio
n, d
iarr
hoea
, con
stip
atio
n, la
xativ
e,
ulce
r
Met
hod:
Dis
cuss
the
harm
ful e
ffect
s of
eat
ing
too
muc
h, e
atin
g th
e w
rong
kin
ds o
f foo
d, a
nd th
e di
seas
es a
ssoc
iate
d w
ith th
is.
Ask
: Wha
t is
diet
ary
fibre
? E
xpla
in th
e im
port
ance
of i
nclu
ding
rou
ghag
e in
our
food
. Ask
the
stud
ents
to li
st th
e im
port
ant
reas
ons
for
eatin
g di
etar
y fib
re.
Ask
: Whe
n do
we
feel
nau
sea
or in
dige
stio
n? E
xpla
in th
e ca
uses
of i
ndig
estio
n an
d ho
w a
cidi
ty in
the
stom
ach
can
be c
ontr
olle
d.
Ask
: Why
is r
ough
age
impo
rtan
t? E
xpla
in th
e im
port
ance
of i
nclu
ding
frui
t and
veg
etab
les
in o
ur d
iet.
Ask
: Wha
t is
an u
lcer
? H
ow is
an
ulce
r ca
used
? D
iscu
ss th
e ba
d ef
fect
s of
eat
ing
very
spi
cy fo
ods.
Exp
lain
the
trea
tmen
t tha
t can
be
take
n to
pre
vent
or
cure
sto
mac
h di
sord
ers.
Dat
e:
Tim
e: 4
0 m
ins
Les
son
plan
161
Uni
t: 2
Topi
c: O
rgan
sy
stem
s in
hum
an
bein
gs
Teac
hing
obj
ecti
ves
Lea
rnin
g ou
tcom
es
Stud
ents
sho
uld
be a
ble
to:
Res
ourc
es/M
ater
ials
Act
ivit
ies/
CW
/HW
3.
The
res
pira
tory
sy
stem
•
to d
escr
ibe
the
par
ts o
f th
e re
spira
tory
sys
tem
and
di
scus
s th
e fu
nctio
ns o
f ea
ch
•to
exp
lain
how
exc
hang
e of
gas
es ta
kes
plac
e in
the
lung
s
•to
exp
lain
the
sim
ilari
ties
and
diffe
renc
es b
etw
een
resp
irat
ion
and
brea
thin
g
•to
dec
ribe
som
e re
spir
ator
y di
seas
es a
nd
disc
uss
thei
r pr
even
tion
and
trea
tmen
t
•de
scri
be th
e pa
rts
of
the
resp
irat
ory
syst
em
•ex
plai
n th
e fu
nctio
n of
ea
ch p
art
•ex
plai
n ho
w g
aseo
us
exch
ange
take
s pl
ace
in
the
lung
s
•di
ffere
ntia
te b
etw
een
resp
irat
ion
and
burn
ing
•de
scri
be th
e ca
uses
, ef
fect
s, a
nd tr
eatm
ent
of r
espi
rato
ry d
isea
ses
Cha
rts
and
diag
ram
s of
the
hum
an
resp
irat
ory
syst
em
Rea
ding
: p 1
5
Act
iviti
es: 1
, 2
CW
: Q3
HW
: Q2
(a)
to (
f)
Pro
ject
: p 1
7
Key
wor
ds: r
espi
ratio
n, th
orac
ic c
avity
, lar
ynx,
trac
hea,
car
tilag
e, r
ib, i
nter
cost
al m
uscl
e, b
ronc
hii,
bron
chio
le, a
lveo
li,
diap
hrag
m, c
ance
r, em
phys
ema,
bro
nchi
tis
Met
hod:
Ask
the
stud
ents
to ta
ke a
dee
p br
eath
with
thei
r ha
nds
on th
eir
ribs
. Ask
them
to b
reat
he o
ut. A
sk: W
hat d
id y
ou fe
el?
Exp
lain
bre
athi
ng m
ovem
ents
. Des
crib
e th
e re
spir
ator
y sy
stem
with
the
help
of c
hart
s an
d di
agra
ms
on th
e bo
ard.
Ask
: Why
do
we
brea
the?
Exp
lain
the
proc
ess
of r
espi
ratio
n an
d ga
seou
s ex
chan
ge in
the
lung
s. A
sk: W
hich
gas
do
we
brea
the
in? W
hich
gas
do
we
brea
the
out?
How
can
you
test
the
gas
that
we
brea
the
out?
Ask
a s
tude
nt to
bre
athe
out
thro
ugh
a dr
inki
ng s
traw
into
a b
eake
r co
ntai
ning
fres
hly
prep
ared
lim
e w
ater
. Ask
: Wha
t hap
pens
? E
xpla
in th
at th
e ai
r w
e br
eath
e ou
t con
tain
s a
lot o
f car
bon
diox
ide
gas
whi
ch tu
rns
the
lime
wat
er m
ilky.
Dis
cuss
the
char
t of H
ow a
ir ch
ange
s in
the
lung
s on
page
15.
Ask
: How
doe
s re
spir
atio
n he
lp th
e bo
dy?
Exp
lain
that
res
pira
tion
is th
e pr
oces
s by
whi
ch fo
od is
bur
ned
to r
elea
se e
nerg
y.
Ask
: How
is r
espi
ratio
n lik
e bu
rnin
g? D
iscu
ss th
e si
mila
ritie
s an
d di
ffere
nces
bet
wee
n bu
rnin
g an
d re
spir
atio
n. A
sk: I
s sm
okin
g ha
rmfu
l? W
hat a
re th
e ba
d ef
fect
s of
sm
okin
g? D
iscu
ss th
e ca
uses
and
effe
cts
of r
espi
rato
ry d
isea
ses
and
how
they
can
be
prev
ente
d an
d tr
eate
d.
Dat
e:
Tim
e: 4
0 m
ins
Les
son
plan
17 1
Uni
t: 2
Topi
c: O
rgan
sy
stem
s in
hum
an
bein
gs
Teac
hing
obj
ecti
ves
Lea
rnin
g ou
tcom
es
Stud
ents
sho
uld
be a
ble
to:
Res
ourc
es/M
ater
ials
Act
ivit
ies/
CW
/HW
3.
The
res
pira
tory
sy
stem
•
to d
escr
ibe
the
par
ts o
f th
e re
spira
tory
sys
tem
and
di
scus
s th
e fu
nctio
ns o
f ea
ch
•to
exp
lain
how
exc
hang
e of
gas
es ta
kes
plac
e in
the
lung
s
•to
exp
lain
the
sim
ilari
ties
and
diffe
renc
es b
etw
een
resp
irat
ion
and
brea
thin
g
•to
dec
ribe
som
e re
spir
ator
y di
seas
es a
nd
disc
uss
thei
r pr
even
tion
and
trea
tmen
t
•de
scri
be th
e pa
rts
of
the
resp
irat
ory
syst
em
•ex
plai
n th
e fu
nctio
n of
ea
ch p
art
•ex
plai
n ho
w g
aseo
us
exch
ange
take
s pl
ace
in
the
lung
s
•di
ffere
ntia
te b
etw
een
resp
irat
ion
and
burn
ing
•de
scri
be th
e ca
uses
, ef
fect
s, a
nd tr
eatm
ent
of r
espi
rato
ry d
isea
ses
Cha
rts
and
diag
ram
s of
the
hum
an
resp
irat
ory
syst
em
Rea
ding
: p 1
5
Act
iviti
es: 1
, 2
CW
: Q3
HW
: Q2
(a)
to (
f)
Pro
ject
: p 1
7
Key
wor
ds: r
espi
ratio
n, th
orac
ic c
avity
, lar
ynx,
trac
hea,
car
tilag
e, r
ib, i
nter
cost
al m
uscl
e, b
ronc
hii,
bron
chio
le, a
lveo
li,
diap
hrag
m, c
ance
r, em
phys
ema,
bro
nchi
tis
Met
hod:
Ask
the
stud
ents
to ta
ke a
dee
p br
eath
with
thei
r ha
nds
on th
eir
ribs
. Ask
them
to b
reat
he o
ut. A
sk: W
hat d
id y
ou fe
el?
Exp
lain
bre
athi
ng m
ovem
ents
. Des
crib
e th
e re
spir
ator
y sy
stem
with
the
help
of c
hart
s an
d di
agra
ms
on th
e bo
ard.
Ask
: Why
do
we
brea
the?
Exp
lain
the
proc
ess
of r
espi
ratio
n an
d ga
seou
s ex
chan
ge in
the
lung
s. A
sk: W
hich
gas
do
we
brea
the
in? W
hich
gas
do
we
brea
the
out?
How
can
you
test
the
gas
that
we
brea
the
out?
Ask
a s
tude
nt to
bre
athe
out
thro
ugh
a dr
inki
ng s
traw
into
a b
eake
r co
ntai
ning
fres
hly
prep
ared
lim
e w
ater
. Ask
: Wha
t hap
pens
? E
xpla
in th
at th
e ai
r w
e br
eath
e ou
t con
tain
s a
lot o
f car
bon
diox
ide
gas
whi
ch tu
rns
the
lime
wat
er m
ilky.
Dis
cuss
the
char
t of H
ow a
ir ch
ange
s in
the
lung
s on
page
15.
Ask
: How
doe
s re
spir
atio
n he
lp th
e bo
dy?
Exp
lain
that
res
pira
tion
is th
e pr
oces
s by
whi
ch fo
od is
bur
ned
to r
elea
se e
nerg
y.
Ask
: How
is r
espi
ratio
n lik
e bu
rnin
g? D
iscu
ss th
e si
mila
ritie
s an
d di
ffere
nces
bet
wee
n bu
rnin
g an
d re
spir
atio
n. A
sk: I
s sm
okin
g ha
rmfu
l? W
hat a
re th
e ba
d ef
fect
s of
sm
okin
g? D
iscu
ss th
e ca
uses
and
effe
cts
of r
espi
rato
ry d
isea
ses
and
how
they
can
be
prev
ente
d an
d tr
eate
d.
Unit 2: Organ systems in human beings Worksheet 1
Name: Date:
1. Complete the table of information about the digestive system.
Part of the digestive system
Gland Juice produced Food it acts upon
mouth
stomach
pancreas
liver
small intestine
2. Complete the sentences on the importance of dietary fibre.
i. It helps avoid
.
ii. It absorbs
.
iii. It allows gut muscles to
.
iv. It helps the body to avoid diseases such as
.
Photocopiable material
181
Unit 2: Organ systems in human beings Worksheet 2
Name: Date:
1. Write the functions of the parts of the respiratory system.
a. larynx:
b. ribcage:
c. intercostal muscles:
d. alveoli:
e. diaphragm:
2. Match the symptoms to the diseases of the respiratory system.
Disease Symptoms
cancer inflammation of the air passages in the lungs; reduces the ability of the lungs to absorb oxygen
bronchitis cells start dividing rapidly until they get out of control
emphysema walls of the alveoli become thin and weak and eventually break down, leaving large empty spaces in the lungs
Photocopiable material
19 1
Teaching objectives:• to explain the system of transport in humans• to describe the structure of the heart and explain how it works• to explain how the circulatory system works• to discuss some transport disorders affected by diet• to explain the absorption and transport of materials in plants• to explain how the structure of roots, stems, and leaves assists in the transport of materials in plants
Teaching strategy:Show the students a sheep’s heart. Ask: What is the function of the heart? Dissect the heart longitudinally and show the students the atria and ventricles. Draw the section of the heart on the board and explain the circulation of blood in it.
Ask: What are the thick blue lines which you can see on the back of your hand? Tell the students to feel their pulse. Ask: Can you see very fine red lines in your eyes? Explain the structure of an artery, a vein, and a capillary, and the difference in functions between them. Help the students perform the various activities.
Ask: Do plants have tissues, organs, and systems? Discuss the vascular system in plants. Ask: Which part of the plant absorbs water? Where does the water go? Explain the transpiration stream and the circulation of water, salts, and food in plants. Explain the structure of xylem and phloem and their functions. With the help of charts and diagrams explain how roots absorb water.
Draw the transverse section of a leaf and explain the position and function of the mesophyll tissue, and how the arrangement of tissues helps a leaf to make food by photosynthesis, and how the arrangement of tissues helps in gaseous exchange. Ask: How is water lost from a plant? Discuss transpiration and its importance for the plant. Set up an experiment to demonstrate that water is lost from the lower surface of a leaf. Discuss the factors which affect the rate of transpiration. Set up a potometer and explain how it is used to measure the uptake of water by the root. Ask: Does a plant need food? How does a plant get its food? Where is food manufactured in a plant? Discuss photosynthesis and the conditions necessary for it to take place.
Ask: How does food manufactured in the leaves reach all the cells and tissues? Discuss the role of the phloem tissue in the transport of food in plants. Ask: Do plants breathe? Explain the process of respiration in plants with the help of diagrams and charts. Show the students prepared slides of the transverse section of a leaf and ask them to observe the stomata and the intercellular spaces between the mesophyll cells.
Summarize the lesson.
Transport systems in plants and animals
UNIT 3
201
Answers to Activities2. To compare the transpiration rates of the two surfaces of a leaf.
Place two equal pieces of cobalt chloride paper, and fix them firmly by cello tape, one on the upper surface and the other on the lower surface of a leaf attached to a plant.
After a few minutes, the cobalt chloride paper shows a change In colour from blue to pink. (Dry cobalt chloride paper changes colour from blue to pink when water touches it). The time taken for the cobalt chloride paper on the upper surface of the leaf to turn pink is much longer than that for the lower surface. So we can say that the rate of transpiration from the lower surface of a leaf is faster than from the upper surface. This is because most leaves have more stomata on the lower surface than on the upper surface.
3. Slow, fast, fast, slow, slow, fast, fast, slow
(a) On a bright, sunny, and windy day
(b) Stomata are open during the daytime.
Wind blows away the water vapour as it passes out, and water evaporates faster when it is hot.
Answers to Exercises in Unit 31. Individual work
2. (a) The heart is made of a special kind of muscle called ‘cardiac muscle’.
(b) Valves present between the atria and the ventricles stop the blood from flowing backwards through the heart.
(c) The heart pumps blood by contracting and relaxing. One complete contraction and relaxation is called a heart beat.
(d) The heart normally beats about 70 times in a minute.
(e) Arteries divide into small thin-walled blood vessels called capillaries. They penetrate into all the tissues of the body. Exchange of food, gases, and materials takes place by diffusion through the thin capillary walls.
3. (a) The body needs more energy when it is working harder, so the breathing rate increases.
(b) The heart beats normally when the body is at rest, but it has to work more when the body is working harder.
(c) The pulse rate would be over 100 times per minute. The breathing rate would be over 25 times per minute.
4 (a) water (b) blood
5. Valves inside the heart help the blood to circulate in one direction only. They stop the backward flow of blood.
6. The transfer of food, gases, and excretory materials between the blood and the cells takes place by diffusion through the thin capillary walls.
Unit 3 Transport systems in plants and animals
21 1
Amazing Science TG 7
7. Plants lose water vapour into the atmosphere by evaporation. The water passes through tiny holes
called stomata which are found mainly on the lower side of leaves. This process is called transpiration.
8. It is important because it helps in the transportation of water in the plants and it also helps a plant to keep cool in summer.
9. (a) An artery is a blood vessel that takes blood away from the heart. It has thick muscular walls to withstand the high pressure of the blood. It usually lies deeply embedded inside the body. It divides into small thin-walled vessels called capillaries.
Capillaries join up to form veins. A vein returns blood to the heart. It is wider than an artery and has thinner walls. It has valves to make sure that the blood flows in one direction only. The blood pressure in an artery is usually low.
(b) In flowering plants materials are circulated in a system of tubes called the vascular system. The vascular system of plants is composed of specialized tissues called xylem and phloem. Xylem is made up of long, dead cells called vessels. Vessels have thick walls. They carry water from the roots, through the stem to the veins in the leaves. Phloem is made up of long thin walled tubes called sieve tubes. Sieve tubes are made of living cells whose horizontal walls have tiny holes. Food flows from the leaves to other parts of the plant through the sieve tubes.
(c) Photosynthesis is a process by which green plants make their own food in the presence of sunlight. It takes place in the green parts of a plant. Oxygen gas is released during photosynthesis.
Respiration is a process by which food is oxidized to release energy. It takes place in all the cells of the body. Carbon dioxide gas is released during respiration, along with heat energy.
(d) Water flows in a continuous stream through a plant. It enters through the roots and flows up the xylem vessels of the root and stem to the leaves and diffuses out of the stomata in the leaves. This evaporation of water from the leaves is called transpiration. Transpiration is the main force which moves water through a plant.
Circulation of blood takes place in the blood vascular system which is composed of the heart, arteries, and veins. It helps to circulate food, oxygen, and food materials inside the body. It also helps to remove waste products such as carbon dioxide and urea from the body.
(e) The absorption of soil water by plants is done by the root hairs which occur in a small zone a short distance behind the root tip. Each root hair is only a part of a cell; however, the vast number of root hairs helps to bring about a very large increase in the absorbing area of the root.
A capillary is a thin walled blood vessel which forms a connection between an artery and a vein. Capillaries penetrate into all the tissues of the body. The transfer of food, gases, and excretory materials takes place by diffusion through the thin capillary walls.
221
Additional Exercise
MCQs
(a) are blood vessels that carry blood away from the heart.
Arteries Veins Capillaries [Arteries]
(b) Arteries divide into small thin-walled vessels called .
veins villi capillaries [capillaries]
(c) Blood vessels that carry blood back to the heart are called .
arteries veins capillaries [arteries]
(d) The heart is made up of a special type of muscle called .
muscle fibre cardiac muscle intercostal muscle [cardiac muscle]
(e) Normally the human heart beats about times in a minute.
40 70 100 [70]
(f) Xylem is the type of vascular tissue through which are transported.
water and mineral salts food and salts water and food
[water and mineral salts]
(g) The evaporation of water from the leaves is called .
respiration translocation transpiration [transpiration]
(h) The transport of food from the leaves to all parts of the plant is called .
respiration translocation transpiration [translocation]
(i) When is the rate of transpiration fastest?
On a bright sunny day At night On a rainy day
[On a bright, sunny day]
(j) Translocation is the movement of in the phloem.
water food oxygen [food]
Unit 3 Transport systems in plants and animals
23 1
Uni
t: 3
Topi
c: T
rans
port
sy
stem
s in
pla
nts
and
anim
als
Teac
hing
obj
ecti
ves
Lea
rnin
g ou
tcom
es
Stud
ents
sho
uld
be a
ble
to:
Res
ourc
es/M
ater
ials
Act
ivit
ies/
CW
/HW
1.
The
cir
cula
tory
sy
stem
•to
des
crib
e th
e tr
ansp
ort s
yste
m in
an
imal
s
•to
des
crib
e th
e st
ruct
ure
of th
e he
art
and
how
it w
orks
•ex
plai
n th
e sy
stem
of
tran
spor
t of m
ater
ials
in
hum
an b
eing
s
•de
scri
be th
e st
ruct
ure
of
the
hear
t and
exp
lain
its
wor
king
A s
heep
’s h
eart
, ch
arts
, dia
gram
s an
d m
odel
s of
the
hum
an
hear
t
Rea
ding
: p 2
0
CW
: Q
1, Q
2
HW
: Q
5, Q
6
Key
wor
ds: b
lood
ves
sel,
arte
ry, v
ein,
cap
illar
y, c
ardi
ac m
uscl
e, c
ham
ber,
atri
um, v
entr
icle
, hea
rtbe
at
Met
hod:
Sho
w th
e st
uden
ts a
she
ep’s
hea
rt. A
sk: W
hat i
s th
e fu
nctio
n of
the
hear
t? D
isse
ct th
e he
art l
ongi
tudi
nally
and
sho
w th
e at
ria
and
the
vent
ricl
es. D
raw
a s
ectio
n of
the
hear
t on
the
boar
d an
d la
bel i
t. E
xpla
in th
e ci
rcul
atio
n of
blo
od in
side
it.
Ask
: Wha
t are
the
thic
k bl
ue li
nes
that
you
can
see
on
the
back
of y
our
hand
? C
an y
ou s
ee v
ery
fine
red
lines
in y
our
eyes
? D
escr
ibe
the
stru
ctur
es o
f an
arte
ry, a
vei
n, a
nd a
cap
illar
y an
d th
e fu
nctio
ns th
at th
ey p
erfo
rm. E
xpla
in th
e di
ffere
nces
bet
wee
n th
em.
Ask
the
stud
ents
to fe
el th
eir
puls
e? E
xpla
in th
at th
is is
a w
ay o
f fee
ling
the
hear
t bea
t. A
sk th
em to
cou
nt th
e nu
mbe
r of
tim
es
thei
r he
art b
eats
in 1
5 se
cond
s. D
iscu
ss w
hat a
hea
rtbe
at is
.
Dat
e:
Tim
e: 4
0 m
ins
Les
son
plan
241
Uni
t: 3
Topi
c: T
rans
port
sy
stem
s in
pla
nts
and
anim
als
Teac
hing
obj
ecti
ves
Lea
rnin
g ou
tcom
es
Stud
ents
sho
uld
be a
ble
to:
Res
ourc
es/M
ater
ials
Act
ivit
ies/
CW
/HW
2.
Hea
rt d
isea
se
•to
exp
lain
the
caus
es o
f he
art d
isea
se
•to
des
crib
e ho
w h
eart
di
seas
es c
an b
e tr
eate
d an
d av
oide
d
•id
entif
y th
e ca
uses
of
hear
t dis
ease
•de
scri
be th
e w
ays
in
whi
ch h
eart
dis
ease
can
be
trea
ted
•ex
plai
n ho
w h
eart
di
seas
e ca
n be
avo
ided
Dia
gram
s an
d pi
ctur
es
of h
eart
dis
ease
and
he
art s
urge
ry
A c
hart
of h
ow h
eart
di
seas
e ca
n be
avo
ided
Rea
ding
: p
20, 2
1
Act
ivity
: 1
CW
: Q3
HW
: Def
ine
the
follo
win
g:
a.
chol
este
rol
b.
thro
mbo
sis
c.
hear
t att
ack
d.
graf
t
e.
pace
mak
er
f. tr
ansp
lant
Key
wor
ds: c
oron
ary
arte
ry, c
hole
ster
ol, t
hrom
bosi
s, a
ngin
a, h
eart
att
ack,
gra
ft, p
acem
aker
, tra
nspl
ant
Met
hod:
Ask
: Wha
t doe
s th
e he
art n
eed
to k
eep
wor
king
pro
perl
y? H
ow a
re fo
od a
nd o
xyge
n su
pplie
d to
the
hear
t? W
hat i
s ch
oles
tero
l? W
hat i
s a
hear
t att
ack?
Des
crib
e ho
w fo
od a
nd o
xyge
n ar
e su
pplie
d to
the
hear
t and
how
a p
oor
diet
can
lead
to a
he
art a
ttac
k. E
xpla
in th
at th
e cl
ottin
g of
blo
od in
the
arte
ries
is c
alle
d th
rom
bosi
s; th
is c
an le
ad to
pai
n in
the
hear
t cal
led
angi
na,
or to
a h
eart
att
ack.
With
the
help
of p
ictu
res
and
if po
ssib
le a
vid
eo/d
vd/y
outu
be c
lip, e
xpla
in h
ow h
eart
sur
gery
is p
erfo
rmed
. Exp
lain
wha
t a g
raft
, a
pace
mak
er, a
nd a
hea
rt tr
ansp
lant
are
. Dis
cuss
the
way
s in
whi
ch h
eart
dis
ease
can
be
avoi
ded.
Dat
e:
Tim
e: 4
0 m
ins
Les
son
plan
25 1
Uni
t: 3
Topi
c: T
rans
port
sy
stem
s in
pla
nts
and
anim
als
Teac
hing
obj
ecti
ves
Lea
rnin
g ou
tcom
es
Stud
ents
sho
uld
be a
ble
to:
Res
ourc
es/M
ater
ials
Act
ivit
ies/
CW
/HW
3.
Tra
nspo
rt s
yste
m
in p
lant
s•
to d
escr
ibe
the
tran
spor
t sys
tem
in
plan
ts
•to
exp
lain
how
roo
ts
abso
rb w
ater
•de
scri
be th
e tr
ansp
ort
syst
em in
pla
nts
•ex
plai
n ho
w r
oots
ab
sorb
wat
er
Dia
gram
s an
d ch
arts
of
the
vasc
ular
sys
tem
in
pla
nts,
slid
es o
f a
root
hai
r, xy
lem
and
ph
loem
Rea
ding
: p 2
2
CW
: Q4
HW
: Des
crib
e th
e va
scul
ar
syst
em in
pl
ants
.
Key
wor
ds: v
ascu
lar
tissu
e, x
ylem
ves
sel,
phlo
em, s
ieve
tube
, roo
t hai
r
Met
hod:
Ask
: Do
plan
ts h
ave
tissu
es, o
rgan
s, a
nd s
yste
ms?
Exp
lain
the
vasc
ular
sys
tem
in p
lant
s.
Ask
: Whi
ch p
art o
f the
pla
nt a
bsor
bs w
ater
? Whe
re d
oes
the
wat
er g
o? D
escr
ibe
the
posi
tions
and
str
uctu
res
of x
ylem
and
phl
oem
. Sh
ow th
e st
uden
ts s
lides
of t
he s
ectio
ns o
f pla
nt ti
ssue
s. D
iscu
ss th
e fu
nctio
ns o
f xyl
em a
nd p
hloe
m. W
ith th
e he
lp o
f dia
gram
s an
d ch
arts
exp
lain
how
roo
ts a
bsor
b w
ater
.
Dat
e:
Tim
e: 4
0 m
ins
Les
son
plan
261
Uni
t: 3
Topi
c: T
rans
port
sy
stem
s in
pla
nts
and
anim
als
Teac
hing
obj
ecti
ves
Lea
rnin
g ou
tcom
es
Stud
ents
sho
uld
be a
ble
to:
Res
ourc
es/M
ater
ials
Act
ivit
ies/
CW
/HW
4.
Flo
w o
f wat
er
thro
ugh
plan
ts
T
rans
port
of
food
in p
lant
s
G
aseo
us
exch
ange
in
plan
ts
•to
def
ine
tran
spir
atio
n an
d ex
plai
n ho
w it
take
s pl
ace
•to
iden
tify
fact
ors
whi
ch a
ffect
the
rate
of
tran
spir
atio
n
•to
exp
lain
the
tran
spor
t of
food
in p
lant
s
•to
exp
lain
how
gas
eous
ex
chan
ge ta
kes
plac
e in
pl
ants
•ex
plai
n ho
w w
ater
and
fo
od a
re tr
ansp
orte
d in
pl
ants
•ex
plai
n ho
w th
e ex
chan
ge o
f gas
es ta
kes
plac
e in
pla
nts
Dia
gram
s an
d ch
arts
of
tran
spor
t of m
ater
ials
in
pla
nts
A s
impl
e ph
otom
eter
, a
leaf
y sh
oot
Rea
ding
: p 2
2, 2
3, 2
4
Act
ivity
: 3
CW
: Q7,
Q8
HW
: Q9
Key
wor
ds: t
rans
pira
tion,
tran
sloc
atio
n
Met
hod:
Ask
: How
doe
s a
plan
t abs
orb
wat
er? W
here
doe
s th
at w
ater
go?
How
doe
s w
ater
cir
cula
te in
a p
lant
? D
iscu
ss th
e ab
sorp
tion
of w
ater
by
the
root
s an
d its
flow
from
the
stem
s to
the
leav
es. E
xpla
in w
hat t
rans
pira
tion
is a
nd th
e fa
ctor
s w
hich
af
fect
the
rate
of t
rans
pira
tion.
Ask
: Doe
s a
plan
t nee
d fo
od?
How
doe
s a
plan
t get
its
food
? Whe
re in
a p
lant
is fo
od m
anuf
actu
red?
Dis
cuss
pho
tosy
nthe
sis
and
the
cond
ition
s ne
cess
ary
for
it to
take
pla
ce. A
sk: H
ow d
oes
the
food
man
ufac
ture
d in
the
leav
es r
each
all
the
cells
and
tiss
ues?
D
iscu
ss th
e ro
le o
f phl
oem
in th
e tr
ansp
ort o
f foo
d in
pla
nts.
Ask
: Do
plan
ts b
reat
he?
Exp
lain
with
the
help
of d
iagr
ams
and
char
ts th
e pr
oces
s of
res
pira
tion
in p
lant
s. Sh
ow th
e st
uden
ts
prep
ared
slid
es o
f the
tran
sver
se s
ectio
n of
a le
af a
nd a
sk th
em to
obs
erve
the
stom
ata
and
the
inte
rcel
lula
r sp
aces
. D
iscu
ss th
e im
port
ance
of t
he tr
ansp
irat
ion
stre
am in
tran
spor
ting
wat
er a
nd m
ater
ials
; for
kee
ping
the
cells
turg
id; f
or k
eepi
ng th
e pl
ant c
ool
in h
ot w
eath
er.
Dat
e:
Tim
e: 4
0 m
ins
Les
son
plan
27 1
Unit 3: Transport systems in plants and animals Worksheet 1
Name: Date:
1. On the diagram below, label the parts of the heart. Draw arrows to show the circulation of the blood inside the heart.
2. On the diagram below, draw arrows to show how water circulates inside a plant.
Photocopiable material
281
Unit 3: Transport systems in plants and animals Worksheet 2
Name: Date:
1. Fill in the blanks to complete the description of heart diseases.
The heart needs and to keep working properly.
The arteries which supply blood to the heart are called arteries.
is a fatty substance which can stick to the walls of an artery and make it
narrow. Bits of break off into the blood stream and block narrow blood
vessels. This blockage is called a . Severe pain in the chest caused by
the coronary arteries becoming partly blocked is called . This kind of
blockage can cause a .
If a coronary artery becomes blocked, a heart surgeon can by-pass the blockage using a piece
of a vein taken from the patient’s leg; this is called a graft. Heart valves can be replaced with
valves, which help to control the heartbeat. Receiving a healthy heart
from another person is called a .
Photocopiable material
29 1
Teaching objectives:• to explain what is meant by growth• to describe how animals and plants grow• to explain reproduction• to describe the kinds of reproduction• to explain the process of pollination, fertilization, and seed and fruit formation• to explain the structure of seeds and fruits• to describe the methods of seed and fruit dispersal and their importance• to explain how a seed germinates
Teaching strategy:Ask: What is growth? How do animals grow? How do plants grow? Can an animal’s tail or ears grow back if they are cut off? Can a plant grow new leaves and branches if its twigs are cut off? Explain that growth is an increase in size which takes place by using food to build more cell material. Growth in animals is limited. Growth in plants is unlimited and takes place at the tips.
Ask: How do living things increase in number? Explain the process of reproduction and its importance in maintaining the continuity of generations.
Ask: How do new plants grow? Can new plants grow from leaves? Explain that some plants are capable of producing new plants if some part is placed in water. Such as the bryophyllum which can grow new plants from its leaves, the money plant can grow new plants from its stem. Show the students an onion bulb and a potato tuber. Slice the bulb. Explain that bulbs are the leaves which store food, and in their centre is a flower bud. Tubers are swollen stems. The eyes are where the buds grow. If a potato is cut up and planted in the ground, each eye can produce a new potato plant. Sow some potato eyes and some onion bulbs in a flower pot. Show them the sprouting leaves and stems. Grow a root garden by burying a carrot, a radish, and a turnip in some sand in a bowl. Keep the water level high enough for the roots to reach the water. After several days green stems and leaves will sprout from the vegetable tops.
Explain that some simple animals can also grow in this way. This method of reproduction is called asexual reproduction and the new plants or animals are exact copies of their parents. Explain the various methods of asexual reproduction with examples. Ask a gardener to show the students cuttings of plants, and explain to them how grafting of scion and stock is done. Explain that there is another method of reproduction in which there is a union of male and female sex cells. This process is called fertilization. The fertilized egg develops into a new individual by cell division. It has characteristics of both parents. Explain the stages of development of a frog, a butterfly and a cockroach from the egg to the adult stage.
Growth and reproduction in living organisms
UNIT 4
301
Ask: Why are flowers brightly coloured? Why do they have a scent and nectar? Explain the importance of pollination and fertilization for the development of fruits and seeds. Ask: Why do seeds need to be dispersed? Explain the importance of dispersal and how seeds and fruits are adapted for dispersal. Show the students some soaked bean seeds. Draw a seed on the board and label it. Tell the students to identify its various parts. Sow some wheat and bean seeds in moist sawdust. Show the students the various stages of germination in both.
Summarize the lesson.
Answers to Exercises in Unit 41. (a) Growth is an increase in the size of an organism. The body of an animal grows all over till it
reaches adult size, after which growth stops. Only some cells retain the power to divide and bring about the repair of worn out or damaged tissues, whereas, plants grow throughout their lives, if they get sufficient warmth, air, light, water, and minerals. Growth in plants is restricted to the tips of the roots and shoots, where cell division occurs. The new cells that are produced grow to a maximum size and then become specialized to form different tissues.
(b) The process by which living organisms produce new living organisms of their own kind is called reproduction. In asexual reproduction the offspring is an exact copy of the parent.
(c) In sexual reproduction there are two parents male and female. In animals the female produces eggs in the ovaries and the male produces sperms in the testes. In plants the ovules are produced in the ovaries of the flowers and the pollen grains are produced in the anthers of the stamens. For sexual reproduction to take place one cell from the male and one cell from the female join together to form new off-spring.
(d) In plants, the pollen is carried from the anther to the stigma of flowers by insects, or by wind. This process is called pollination. After pollination, a pollen tube grows out from the pollen grain and enters the ovule. The male gamete is released and joins with the female gamete. This process is called fertilization.
(e) After fertilization all the parts of the flower dry up and fall off except the ovary which grows rapidly to form the fruit. The ovules form the seeds.
(f) Fruits and seeds are dispersed in different ways. Some seeds and fruits have feathery hairs or wings by which they are carried by wind to far away places. Some seeds and fruits have small hooks by which they get attached to the fur of animals. Some juicy fruits are eaten by birds. Their seeds remain undigested and they are passed out of their gut away from the parent plant. Some flowers produce pods which dry up in the Sun. The pod splits and the two halves curl up and flick out the seeds.
2. (a) A fruit is the part of the plant that contains seeds.
(b) Seeds need to be dispersed or scattered away from the parent plant so that each seed has a chance to grow into a new plant.
(c) A seed has the baby plant or embryo, which is made up of a baby shoot or plumule, and a baby root or radicle, and one or two seed leaves or cotyledons, which contain stored food.
(d) Seeds need a store of food for the growth of the embryo till the shoot develops its own green leaves.
Unit 4 Growth and reproduction in living organisms
31 1
Amazing Science TG 7
3. (a) anthers
(b) stigma
(c) petals are brightly coloured
(d) the petals shrivel and fall off; the ovary either swells up or dries up to form the fruit; the ovules develop into seeds
(e) pollen and nectar
4. (a) growth (b) adult (c) mitosis (d) clones (e) binary fission (f) buds
5. (a) binary fission (b) by spores (c) forms buds (d) swollen underground (e) part of a stem (f) a stock and scion (g) in ovaries (h) has cones (i) is the resting period of a seed
6. Insect-pollinated flowers Wind-pollinated flowers
large, brightly coloured small, green
present absent
present absent
large, sticky powdery, numerous
large, inside the flower have long filaments, hang outside the flower
large, sticky feathery, hang outside flower.
7. tube, pollen, ovule, gamete, seed, fruit
Additional Exercise
MCQs
(a) The increase in the size of an organism is called .
growth reproduction elongation [growth]
(b) Growth in plants takes place at the of the root and shoot.
sides tips base [tips]
(c) The type of reproduction in which there is only one adult of the species is called .
sexual reproduction asexual reproduction fission [asexual reproduction]
(d) Yeast is a simple non-green plant that reproduces by .
cuttings tubers budding [budding]
321
(e) The process by which pollen from the anther is carried to the stigma of a flower is called .
fertilization germination pollination [pollination]
(f) The process of the joining of male and female cells is called .
fertilization germination pollination [fertilization]
(g) Pine trees produce male and female reproductive organs called .
fruits seeds cones [cones]
(h) The process by which the embryo of a seed grows into a new plant is called .
germination pollination fertilization [germination]
(i) The scattering of seeds away from the parent plant is called .
dispersal pollination fertilization [dispersal]
(j) When a seed is planted in the soil it absorbs water through the .
testa micropyle cotyledon [micropyle]
Unit 4 Growth and reproduction in living organisms
33 1
Uni
t: 4
Topi
c: G
row
th a
nd
repr
oduc
tion
in
livi
ng o
rgan
ism
s
Teac
hing
obj
ecti
ves
Lea
rnin
g ou
tcom
es
Stud
ents
sho
uld
be
able
to:
Res
ourc
es/M
ater
ials
Act
ivit
ies/
CW
/HW
1.
Gro
wth
•
to d
efin
e gr
owth
•to
exp
lain
that
th
ere
are
two
kind
s of
rep
rodu
ctio
n
•to
des
crib
e as
exua
l re
prod
uctio
n
•ex
plai
n w
hat i
s m
eant
by
grow
th
•ex
plai
n w
hat
repr
oduc
tion
is
•de
scri
be a
sexu
al
repr
oduc
tion
in a
nim
als
and
plan
ts
Dia
gram
s an
d ch
arts
of
asex
ual r
epro
duct
ion
in
anim
als,
spe
cim
ens
of
asex
ual r
epro
duct
ion
in
plan
ts (
pota
toes
with
‘eye
s’,
carr
ot, r
adis
h, tu
rnip
)Po
ts o
f com
post
for
plan
ting
thes
e ve
geta
bles
, an
oni
on b
ulb
Rea
ding
: p 2
9, 3
0, 3
1
Act
ivity
: 1, 2
CW
: Q4
HW
: Q1
(a)
(b)
Key
wor
ds: g
row
th, r
epro
duct
ion,
ase
xual
, clo
ne, m
itosi
s, b
inar
y fis
sion
, bud
, spo
rang
ia, b
uddi
ng, s
pore
, eye
, run
ner,
cutt
ing,
gr
afte
d, s
tock
, sci
onM
etho
d: A
sk: W
hat i
s gr
owth
? H
ow d
o an
imal
s gr
ow?
How
do
plan
ts g
row
? C
an a
pla
nt g
row
new
leav
es a
nd b
ranc
hes
if tw
igs
are
cut o
ff? C
an a
n an
imal
’s ta
il or
ear
s gr
ow b
ack
if th
ey a
re c
ut o
ff? E
xpla
in th
at g
row
th is
an
incr
ease
in s
ize
whi
ch ta
kes
plac
e by
usi
ng fo
od to
bui
ld m
ore
cell
mat
eria
l. G
row
th in
ani
mal
s is
lim
ited.
Gro
wth
in p
lant
s is
unl
imite
d an
d ta
kes
plac
e at
the
tips.
Ask
: How
do
livin
g th
ings
incr
ease
in n
umbe
r? E
xpla
in th
e pr
oces
s of
rep
rodu
ctio
n an
d its
impo
rtan
ce in
mai
ntai
ning
the
cont
inui
ty o
f spe
cies
. Ask
: Can
ani
mal
s re
prod
uce
asex
ually
? E
xpla
in th
e m
etho
d of
ase
xual
rep
rodu
ctio
n in
sim
ple
anim
als
like
the
amoe
ba a
nd h
ydra
. Exp
lain
that
indi
vidu
als
that
are
pro
duce
d by
ase
xual
rep
rodu
ctio
n ar
e ex
act c
opie
s of
thei
r pa
rent
s.
Ask
: How
do
new
pla
nts
grow
? C
an n
ew p
lant
s gr
ow fr
om le
aves
? E
xpla
in th
at s
ome
plan
ts a
re c
apab
le o
f pro
duci
ng n
ew p
lant
s if
som
e pa
rt is
pla
ced
in w
ater
. A b
ryop
hyllu
m p
lant
can
gro
w n
ew p
lant
s fr
om it
s le
aves
. The
mon
ey p
lant
can
gro
w n
ew p
lant
s fr
om it
s st
em. S
how
the
stud
ents
an
onio
n bu
lb a
nd a
pot
ato
tube
r. Sl
ice
the
bulb
. Exp
lain
that
bul
bs a
re m
ade
up o
f fle
shy
leav
es
whi
ch s
tore
food
, and
in th
eir
cent
re is
a fl
ower
bud
. Tub
ers
are
swol
len
stem
s. T
he e
yes
of a
pot
ato
are
whe
re th
e bu
ds g
row
. If a
po
tato
is c
ut u
p an
d pl
ante
d in
the
soil,
eac
h ey
e ca
n pr
oduc
e a
new
pot
ato
plan
t.In
a fl
ower
pot
, sow
som
e po
tato
pie
ces
with
eye
s an
d an
oni
on b
ulb.
Aft
er a
few
day
s, s
how
the
stud
ents
the
spro
utin
g le
aves
and
st
ems.
Gro
w a
roo
t gar
den
by b
uryi
ng a
car
rot,
a ra
dish
, and
a tu
rnip
in s
and
in a
bow
l. K
eep
the
wat
er le
vel h
igh
enou
gh fo
r th
e ro
ots
to r
each
the
wat
er. A
fter
a fe
w d
ays,
gre
en s
tem
s an
d le
aves
will
spr
out f
rom
the
vege
tabl
e to
ps.
Ask
a g
arde
ner
to s
how
the
stud
ents
cut
tings
of p
lant
s an
d ex
plai
n ho
w g
raft
ing
of s
cion
and
sto
ck is
don
e.
Dat
e:
Tim
e: 4
0 m
ins
Les
son
plan
341
Uni
t: 4
Topi
c: G
row
th a
nd
repr
oduc
tion
in
livi
ng o
rgan
ism
s
Teac
hing
obj
ecti
ves
Lea
rnin
g ou
tcom
es
Stud
ents
sho
uld
be a
ble
to:
Res
ourc
es/M
ater
ials
Act
ivit
ies/
CW
/HW
2.
Sexu
al
repr
oduc
tion
•to
def
ine
sexu
al
repr
oduc
tion
•to
des
crib
e se
xual
re
prod
uctio
n in
flo
wer
ing
plan
ts
•de
fine
sexu
al
repr
oduc
tion
•ex
plai
n ho
w it
take
s pl
ace
in fl
ower
ing
plan
ts
Cha
rts
and
diag
ram
s of
pol
linat
ion
and
fert
iliza
tion
Rea
ding
: p 3
2, 3
3
Act
ivity
: 3
CW
: Q6,
Q7
HW
: Q1
(c)
(d)
Q
3
Key
wor
ds: s
exua
l rep
rodu
ctio
n, o
vule
, ova
ry, p
olle
n gr
ain,
ant
her,
stam
en, p
ollin
atio
n, s
elf p
ollin
atio
n, w
ind
polli
natio
n,
fert
iliza
tion,
egg
, spe
rm, p
olle
n tu
be, f
ruit,
con
e, p
olle
n sa
c, a
xis,
sca
le
Met
hod:
Def
ine
sexu
al r
epro
duct
ion.
Exp
lain
that
the
mal
e an
d fe
mal
e se
x ce
lls jo
in to
geth
er to
form
a fe
rtili
zed
egg
whi
ch
deve
lops
into
a n
ew in
divi
dual
by
cell
divi
sion
. It h
as c
hara
cter
istic
s of
bot
h pa
rent
s.
Ask
: Why
are
flow
ers
brig
htly
col
oure
d? W
hy d
o th
ey h
ave
a sc
ent a
nd n
ecta
r? E
xpla
in th
e im
port
ance
of p
ollin
atio
n an
d fe
rtili
zatio
n fo
r th
e de
velo
pmen
t of s
eeds
whi
ch g
row
into
new
pla
nts
of th
e sa
me
kind
. Def
ine
polli
natio
n an
d ex
plai
n th
e m
etho
ds o
f sel
f-po
llina
tion
and
cros
s-po
llina
tion.
Des
crib
e th
e ch
arac
teri
stic
s of
inse
ct-p
ollin
ated
and
win
d-po
llina
ted
flow
ers.
Ask
: Wha
t hap
pens
aft
er a
pol
len
grai
n la
nds
on th
e st
igm
a of
a fl
ower
of t
he s
ame
kind
? D
iscu
ss th
e gr
owth
of t
he p
olle
n tu
be
and
how
a p
olle
n gr
ain
cell
com
bine
s w
ith a
n eg
g ce
ll to
pro
duce
a fe
rtili
zed
egg
cell.
Dis
cuss
frui
t and
see
d fo
rmat
ion.
Dis
cuss
th
e pr
oces
s of
pol
linat
ion
and
fert
iliza
tion
in p
lant
s th
at d
o no
t pro
duce
flow
ers.
Giv
e th
e ex
ampl
e of
a p
ine
tree
. Exp
lain
that
it
has
mal
e an
d fe
mal
e co
nes
whi
ch p
rodu
ce o
vule
s an
d po
llen
sacs
on
thei
r sc
ales
. Win
d po
llina
tion
take
s pl
ace
and
the
prod
uctio
n of
see
ds ta
kes
thre
e ye
ars.
Dat
e:
Tim
e: 4
0 m
ins
Les
son
plan
35 1
Uni
t: 4
Topi
c: G
row
th a
nd
repr
oduc
tion
in
livi
ng o
rgan
ism
s
Teac
hing
obj
ecti
ves
Lea
rnin
g ou
tcom
es
Stud
ents
sho
uld
be a
ble
to:
Res
ourc
es/M
ater
ials
Act
ivit
ies/
CW
/HW
3.
Seed
s an
d fr
uits
•to
exp
lain
how
see
ds
and
frui
ts a
re fo
rmed
•to
dis
cuss
the
disp
ersa
l of s
eeds
and
fr
uits
•de
scri
be th
e pr
oces
s of
se
ed a
nd fr
uit f
orm
atio
n
•ex
plai
n th
e fo
rmat
ion
of
diffe
rent
kin
ds o
f fru
its
•ex
plai
n th
e w
ays
in w
hich
se
eds
and
frui
ts a
re
disp
erse
d
Spec
imen
s of
sof
t and
fle
shy
frui
ts, d
ry fr
uits
diag
ram
s an
d ch
arts
of
diff
eren
t kin
ds o
f fr
uit
Rea
ding
: p 3
3, 3
4
CW
: Q5
HW
: Q2
Key
wor
ds: s
eed,
dor
man
cy, f
ruit,
pod
, cap
sule
, dis
pers
e, h
air,
win
g
Met
hod:
Ask
: Wha
t is
a se
ed? W
hat i
s a
frui
t? H
ow a
re s
eeds
and
frui
ts fo
rmed
? D
iscu
ss th
e pr
oces
s of
see
d an
d fr
uit f
orm
atio
n.
Exp
lain
that
a s
eed
may
be
soft
and
fles
hy li
ke a
tom
ato,
or
it m
ay b
e dr
y an
d ha
rd li
ke a
pea
pod
. Exp
lain
the
diffe
rent
kin
ds o
f fr
uit a
nd th
e m
etho
ds o
f the
ir d
ispe
rsal
.
Ask
: Why
are
frui
ts fo
rmed
? Why
mus
t see
ds b
e di
sper
sed?
Exp
lain
that
the
seed
s ne
ed to
be
scat
tere
d aw
ay fr
om th
e pa
rent
pla
nt
so th
at e
ach
seed
has
a c
hanc
e to
gro
w.
Dat
e:
Tim
e: 4
0 m
ins
Les
son
plan
361
Unit 4: Growth and reproduction in living organisms Worksheet 1
Name: Date:
1. Fill in the table to show how fruit and seed dispersal take place.
Seed/fruit Adaptation Method of dispersal
dandelion
sycamore
burdock
guava
blackberry
pea pod
coconut
2. Match the organism to its method of asexual reproduction:
Name of organism Method of reproduction
amoeba budding
paramecium binary fission
hydra spores
yeast eyes
fungi budding
potato runner
strawberry budding
rose grafting
mango cutting
Photocopiable material
37 1
Unit 4: Growth and reproduction in living organisms Worksheet 2
Name: Date:
Q. Fill in the blanks to complete the description of how seeds and fruits are formed.
In plants, during pollination the or the male cells are carried from
the to the stigma of flowers by insects or by the wind. The
cells and the cells unite to produce seeds which
grow into new plants. After pollination, a pollen grows from the pollen
grain. It enters the and the male gamete is released. It joins with the
female gamete and the ovule becomes a . The wall of the ovary grows to
form the .
Pine trees produce male and female reproductive organs called which
are made up of woody arranged around an .
Each scale of a female cone has ovules. Male cones are small. They
have pollen on their scales. carries the pollen
grains to the ovules of the female cones. and production of seeds takes
three years.
Photocopiable material
381
Test paper 1Time: 3 hours Total marks: 100
1. Attempt any 5 questions. [All questions carry equal marks.] [40]
(a) Describe the stem of a plant. (b) What is a skeleton? What are the different types of skeletons found in animals? (c) How is water lost from a plant? What is the importance of transpiration for a plant? (d) Differentiate between: (i) an artery and a vein (ii) xylem and phloem (iii) photosynthesis and respiration (iv) transpiration and circulation (v) a root hair and a capillary (e) What is pollination? What happens after pollination? How is a fruit formed? (f) What are the important features of a natural environment? (g) What is a food chain? What are herbivores, carnivores, omnivores, and decomposers, and how
are they linked in a food chain? (h) Define reproduction. What are the various methods of asexual reproduction in plants?
2. Draw labelled diagrams of:
(a) The longitudinal section of a root [5]
(b) The structure of a seed [5]
(c) The nitrogen cycle [10]
3. Name the correct part of the digestive system. [10]
(a) Food is broken into small pieces by the .
(b) Digestion starts in the .
(c) Gastric juice is produced in the .
(d) Pancreatic juice comes from the .
(e) Bile is made in the .
(f) Intestinal juice is made in the .
(g) Water is absorbed from undigested food in the .
(h) Faeces are passed out of the body through the .
(i) Absorption of digested food takes place through the .
4. Arrange the following activities in the correct sequence to show what happens when we breathe: [10] (a) The intercostal muscles relax. (b) The intercostal muscles contract. (c) The diaphragm relaxes. (d) The diaphragm contracts.
Test paper 1
39 1
(e) The chest gets smaller. (f) The chest gets larger. (g) Air is sucked into the lungs. (h) Air is forced out of the lungs.
5. Match the items of lists A and B. [10]
A B (a) An amoeba reproduces by forming buds (b) Fungi reproduce swollen underground stem (c) A sea anemone binary fission (d) A potato tuber is a by spores (e) A cutting is a stock and scion (f) Grafting needs in ovaries (g) Ovules are produced part of a stem (h) Sperm are produced has cones (i) A pine tree the resting period of a seed (j) Dormancy is in testes
6. Match the plant/animal to its adaptation. [10]
Plant/Animal Adaptation (a) water plants spines and hair on stem (b) swamp plants grow on tree trunks (c) evergreens special breathing roots (d) desert plants air spaces in leaves and stems (e) epiphytes waxy, needle-like leaves (f) whale thick, scaly skin (g) lizard layer of fat called blubber (h) mountain goat thick fur coat (i) snow leopard webbed feet (j) water birds strong hoofs
Test paper 1
401
Teaching objectives:• to explain that the study of interrelationships of organisms and their environment is called ecology,
and the people who study ecology are called ecologists• to explain that the living place of animals and plants is called habitat, and that there are many
kinds of habitats• to explain that the surroundings of plant or an animal is called environment• to explain that different types of environment have distinct characteristics that animals and plants
have to adapt to in order to survive• to explain that animals depend on green plants for food and that green plants depend on the Sun’s
energy• to explain that all living things are the food of other living things, and are eaten by decomposers
when they die• to explain that the elements in an ecosystem are recycled to maintain a balance in their proportions
Teaching strategy:Write the word ecology on the board. Ask: Do you know what it means? Explain that ‘eco’ means home and ‘logos’ means study. Ecology is the study of living organisms in their natural homes. An ecosystem includes the plants and animals and their immediate surroundings. So ecology is the study of interdependence of organisms and their environment. Ask: What does environment mean? Explain that environment means the surroundings of a living thing. Show the students pictures of bees, ants, or wasps living in a colony, animals living in a herd, a flock of birds, etc. Explain that when a group of plants and animals live together in the same area, they are called a community. A community is made up of many populations. A population is a particular kind of plant or animal that lives in a community. A farm community may have a population of horses, cows, etc.
Explain that the grasshopper eats grass. It is a primary consumer. A primary consumer is the first animal in a food chain that eats a plant. Ask: Can you think of other primary consumers? Explain that all herbivores are primary consumers. Animals that eat primary consumers are called secondary consumers in a food chain. If a frog eats a grasshopper and is then eaten by a snake, the snake would be the third consumer in the food chain. A hawk could eat the snake. The hawk would then be the fourth consumer in the food chain. When the hawk dies, other animals eat it, or bacteria and fungi turn the remains of the hawk into soil. The soil then becomes rich in minerals and nutrients to grow new plants. Draw a picture of the food chain marking it with arrows from the first to the fourth consumer. Tell the children to make food chains with pictures cut from magazines. Explain that all food chains start with the Sun, and the first living thing in a food chain is a green plant. A food chain
Living organisms and their environment
UNIT 5
41 1
traces the chain of energy that transfers from plants, (that produce food) to animals, (that consume food) and then to other animals that consume these.
Draw a spider’s web on the board. Ask: What happens when you shake the web? Explain that it bounces around but stays together. Ask: What happens to the shape of the web if one small strand breaks? Explain that the shape of the web changes slightly. Ask: What happens if a big strand breaks? Explain that a food web is like a spider web. Food web is a complex system in which animals can be in more than one food chain. For example, rabbits, squirrels and mice all eat plants. Rabbits are eaten by foxes and hawks. Squirrels are also eaten by foxes and hawks.
Ask: Can you name any other kinds of population? Show some pictures of busy, crowded streets. Ask: How do you feel being held up in traffic, or standing in a long line at the ticket office of a park or zoo? Explain that when a population of a community becomes too large, people begin to compete with each other for space and position. Only the strongest or fastest survive. Ask: What would happen if you plant twenty seeds in one pot? Explain that as the seeds sprout they will begin to compete for space, water, and sunlight. Some seeds will produce long stems with many leaves. Others will probably shrivel up and die. The strongest plants will grow best in the overpopulated pot. Show the students pictures of animals with protective parts like claws, teeth, beaks, hooves, etc. and plants with spines and thorns. Discuss the functions of each part. Explain that all living things grow and change to suit their environment. These changes are called adaptations. Adaptation means that a plant or animal changes to fit its environment so that it can survive. Species of animals or plants that cannot adapt will die or they might become extinct.
Ask: What did you eat for breakfast? Where did the bread come from? Where did the wheat for the bread come from? Explain that green plants are producers. They are able to make their own food from the Sun’s energy. These plants provide food for animal. Animals are the consumers of food. Some animals eat other animals. Plant eaters are called herbivores and meat eaters are called carnivores. Show the students pictures of assorted animals. Ask: Can you guess what kind of food each animal eats? Animals that eat both plants and animals are called omnivores. Show the students a picture of a grasshopper, a frog, a snake and a hawk. Explain that the food chains are interlocked and interwoven like a spider web. Many food chains make up a food web. If one small chain in the food web breaks, not much damage is done. But if a major part of a chain is broken, a lot of damage can occur. The whole food web could collapse. Draw a food chain on the board.
Ask: Which organisms are the largest in numbers? Which organisms are biggest in size? Explain the pyramid of numbers. As the energy flows through a food chain, it is lost at every level. The position of an organism in a food chain is called its trophic level. The number of consumers at every trophic level decreases, whereas their size increases as they consume more of the organisms from the level below them. The transfer of energy is reduced at every level, and the amount of energy passed on to the fourth level is reduced to such an extent that it cannot support another population of consumers. Ask: How much oxygen, nitrogen, carbon dioxide, and water vapour is there in the atmosphere? What do living things use oxygen for? What do living things use carbon dioxide for? What do living things use nitrogen for? How do we use water? How does the level of all these elements remain constant in the atmosphere? How are they replaced? Explain the natural cycles of carbon, nitrogen, and water with diagrams and charts.
Summarize the lesson.
Amazing Science TG 7
421
Answers to Exercises in Unit 51. (a) The branch of biology which deals with the relationships between the living organisms
themselves and with their surroundings is known as ecology. Scientists who study these interrelationships are called ecologists.
(b) The two main types of environment are:
(i) Natural environment: Animals live in such natural conditions for which they are best suited. Since their bodies are well adapted to these conditions they are found in one particular habitat. For example, squirrels are found in woodlands.
(ii) Artificial environment: An environment which is created by man is called an artificial environment. Factors such as temperature, light, water and minerals are controlled to produce ideal conditions for the organisms to live. For example, zoos, aquariums, and greenhouses are artificial environment.
(c) The important features of a natural environment are climate, soil, landscape, and other living organisms.
(d) The place where animals and plants live is called habitat. All the things which affect the way of life of an organism are called its environment. A group of living things sharing a habitat is called a community. The number of creatures of the same kind living in a habitat are called population.
(e) The characteristic features of an organism, which enable it to obtain everything that it needs from its habitat are called adaptation. The roots of desert plants spread out just below the surface of the ground. Their stems are thick and fleshy. There are spines and hair on the stems and leaves. Some trees have deep roots. Small animals hide under rocks and stones or in sand. They come out at night. Camels store food in their humps, and water in special pouches in their stomachs. Lizards have thick scaly skins.
(f) A food chain comprises of a series of organisms, each dependent on the next as a source of food and energy. Herbivores are animals that eat plants like cow. Carnivores are animals that eat meat like lion. Omnivores are animals that eat both plants and animals like crow. Decomposers are bacteria and fungi which break down the bodies of dead plants and animals.
(g) The position of an organism in a food chain is called its trophic level. Green plants usually occupy the first trophic level, herbivores the second and carnivores the third and fourth trophic levels. Most food chains do not have more than four trophic levels because some energy is lost at each level and a limit is reached by the fourth trophic level. The amount of energy available is reduced to such an extent that it cannot support another population of consumers.
2. (a) environment (b) squirrel (c) air spaces in leaves (d) feathers (e) omnivores3. (a) air spaces in leaves and stems (b) special breathing roots (c) waxy, needle-like leaves (d) spines and hair on stem (e) grow on tree trunks (f) layer of fat called blubber (g) hibernates (h) stores food in its hump (i) thick scaly skin (j) strong hoofs (k) thick fur coat (l) scales and gills (m) webbed feet
4. Refer to Pupil’s Book.
5. b, a, c
Unit 5 Living organisms and their environment
43 1
Additional Exercise
MCQs
(a) Things which affect the way of life of an organism are called .
habitat environment community [environment]
(b) Which one of the following animals is warm-blooded?
Fish Frog Squirrel [Squirrel]
(c) Which one of the following is not an adaptation of desert plants?
Thick stem Deep roots Air spaces in the leaves
[Air spaces in the leaves]
(d) An adult frog breathes through its .
lungs gills fins [lungs]
(e) The body of a bird is covered with .
hair scales feathers [feathers]
(f) Animals that eat both plants and animals are called .
herbivores carnivores omnivores [omnivores]
(g) Many food chains are inter-connected to form a .
food cycle food chain food web [food web]
(h) The position of an organism in a food chain is called its .
water level trophic level tropic level [trophic level]
(i) At the base of every food chain, green plants are the .
producers consumers decomposers [producers]
(j) Bacteria and fungi which break down the bodies of dead plants and animals in the soil are called .
scavengers decomposers carnivores [decomposers]
Amazing Science TG 7
441
Uni
t: 5
Topi
c: L
ivin
g or
gani
sms
and
thei
r en
viro
nmen
t
Teac
hing
obj
ecti
ves
Lea
rnin
g ou
tcom
es
Stud
ents
sho
uld
be a
ble
to:
Res
ourc
es/M
ater
ials
Act
ivit
ies/
CW
/HW
1.
Hab
itat a
nd
envi
ronm
ent
•to
def
ine
ecol
ogy
and
desc
ribe
the
wor
k of
an
eco
logi
st
•to
def
ine
habi
tat,
com
mun
ity, a
nd
popu
latio
n
•to
def
ine
an
ecos
yste
m
•de
fine
ecol
ogy
and
expl
ain
wha
t eco
logi
sts
do
•ex
plai
n th
e re
latio
nshi
p be
twee
n ha
bita
t, co
mm
unity
, and
po
pula
tion
•de
scri
be a
n ec
osys
tem
an
d w
hat c
onst
itute
s it
Pic
ture
s of
diff
eren
t ki
nds
of e
nvir
onm
ent
and
habi
tat,
and
the
kind
s of
org
anis
ms
livin
g th
ere
Rea
ding
: p 3
9, 4
0
Act
ivity
: 1, 2
CW
: Q1
(a)
HW
: Q1
(d)
Key
wor
ds: h
abita
t, en
viro
nmen
t, ec
olog
y, e
colo
gist
, com
mun
ity, p
opul
atio
n
Met
hod:
Wri
te th
e w
ord
EC
OL
OG
Y o
n th
e bo
ard.
Ask
: Do
you
know
wha
t it m
eans
? E
xpla
in th
at ‘e
co’ m
eans
hom
e an
d ‘lo
gos’
m
eans
stu
dy. E
colo
gy m
eans
the
stud
y of
livi
ng o
rgan
ism
s in
thei
r na
tura
l hom
es. A
n ec
osys
tem
incl
udes
the
plan
ts a
nd a
nim
als
and
thei
r im
med
iate
sur
roun
ding
s. So
eco
logy
is th
e st
udy
of th
e in
terd
epen
denc
e of
org
anis
ms
and
thei
r en
viro
nmen
t. A
sk: W
hat
does
env
iron
men
t mea
n? E
xpla
in th
at e
nvir
onm
ent m
eans
the
surr
ound
ings
of a
livi
ng th
ing.
It i
nclu
des
the
phys
ical
con
ditio
ns
such
as
clim
ate,
soi
l, w
ater
, etc
. It a
lso
incl
udes
the
orga
nism
s liv
ing
ther
e.
Ask
: Wha
t is
a ha
bita
t? E
xpla
in th
at th
e ph
ysic
al c
ondi
tions
suc
h as
ligh
t, te
mpe
ratu
re, w
ater
, and
soi
l whi
ch a
ffect
the
lives
of t
he
anim
als
and
plan
ts li
ving
in a
par
ticul
ar p
lace
are
cal
led
thei
r ha
bita
t. Sh
ow th
e st
uden
ts p
ictu
res
of b
ees
or a
nts
livin
g in
a c
olon
y,
anim
als
livin
g in
a h
erd,
a fl
ock
of b
irds
, etc
. Exp
lain
that
whe
n a
grou
p of
pla
nts
and
anim
als
live
toge
ther
in th
e sa
me
habi
tat,
they
are
cal
led
a co
mm
unity
. A c
omm
unity
is m
ade
up o
f man
y di
ffere
nt p
opul
atio
ns. A
pop
ulat
ion
is a
par
ticul
ar k
ind
of p
lant
or
ani
mal
that
live
s in
a c
omm
unity
. For
exa
mpl
e a
farm
com
mun
ity m
ay h
ave
a po
pula
tion
of h
orse
s, c
ows,
etc
. The
re a
re m
any
diffe
rent
kin
ds o
f hab
itat s
uch
as w
oodl
and,
gra
ssla
nd, r
iver
, coa
st, e
tc.
Ask
: Wha
t is
envi
ronm
ent?
Exp
lain
that
all
thin
gs th
at a
ffect
the
way
of l
ife o
f a p
lant
or
anim
al a
re c
alle
d its
env
iron
men
t. E
nvir
onm
ent i
nclu
des
the
phys
ical
con
ditio
ns s
uch
as c
limat
e, s
oil,
wat
er, e
tc. a
nd a
ll th
e ot
her
orga
nism
s liv
ing
in th
e sa
me
plac
e.
Ask
: Wha
t is
an e
cosy
stem
? E
xpla
in th
at a
n ec
osys
tem
is a
com
mun
ity o
f org
anis
ms
toge
ther
with
the
habi
tat i
n w
hich
they
live
. A
n ec
osys
tem
is m
ade
up o
f all
the
prod
ucer
s an
d co
nsum
ers
in a
com
mun
ity, a
s w
ell a
s th
e ph
ysic
al e
nvir
onm
ent.
Dat
e:
Tim
e: 4
0 m
ins
Les
son
plan
45 1
Uni
t: 5
Topi
c: L
ivin
g or
gani
sms
and
thei
r en
viro
nmen
t
Teac
hing
obj
ecti
ves
Lea
rnin
g ou
tcom
es
Stud
ents
sho
uld
be a
ble
to:
Res
ourc
es/M
ater
ials
Act
ivit
ies/
CW
/HW
2.
Typ
es o
f en
viro
nmen
t•
to d
escr
ibe
diff
eren
t ty
pes
of e
nvir
onm
ent
•to
iden
tify
the
impo
rtan
t fea
ture
s of
a
natu
ral e
nvir
onm
ent
•de
scri
be v
ario
us k
inds
of
envi
ronm
ent
•de
scri
be th
e im
port
ant
feat
ures
of a
nat
ural
en
viro
nmen
t
Pic
ture
s of
diff
eren
t ki
nds
of a
rtifi
cial
and
na
tura
l env
iron
men
t
Rea
ding
: p 4
0, 4
1
CW
: Q1
(b)
HW
: Q1
(c)
Key
wor
ds: a
rtifi
cial
env
iron
men
t, na
tura
l env
iron
men
t, cl
imat
e, s
oil,
land
scap
e
Met
hod:
Sho
w th
e st
uden
ts p
ictu
res
of a
n aq
uari
um a
nd a
zoo
. Dis
cuss
why
ani
mal
s ar
e ke
pt th
ere.
Exp
lain
wha
t an
artif
icia
l en
viro
nmen
t is.
Ask
: Wha
t is
a na
tura
l env
iron
men
t for
frog
s? F
or fi
sh?
For
squi
rrel
s? D
iscu
ss th
e na
tura
l env
iron
men
t of d
iffer
ent
kind
s of
pla
nt a
nd a
nim
al. D
iscu
ss th
e im
port
ant f
eatu
res
of a
nat
ural
env
iron
men
t. E
xpla
in th
at a
nim
als
and
plan
ts li
ve in
the
natu
ral c
ondi
tions
for
whi
ch th
ey a
re b
est s
uite
d.
Dat
e:
Tim
e: 4
0 m
ins
Les
son
plan
461
Uni
t: 5
Topi
c: L
ivin
g or
gani
sms
and
thei
r en
viro
nmen
t
Teac
hing
obj
ecti
ves
Lea
rnin
g ou
tcom
es
Stud
ents
sho
uld
be a
ble
to:
Res
ourc
es/M
ater
ials
Act
ivit
ies/
CW
/HW
3.
Ada
ptat
ions
•
to e
xpla
in h
ow
plan
ts a
nd a
nim
als
are
adap
ted
to
live
in a
par
ticul
ar
envi
ronm
ent
•ex
plai
n ho
w a
nim
als
and
plan
ts a
re a
dapt
ed
to li
ve in
a p
artic
ular
en
viro
nmen
t
Rea
ding
: p 4
2, 4
3, 4
4
CW
: Q3
HW
: Q1
(e)
Key
wor
ds: a
dapt
atio
n, d
eser
t, w
ater
, sw
amp,
mou
ntai
n, e
piph
yte,
war
m-b
lood
ed, c
old-
bloo
ded,
hib
erna
te, f
ores
t, se
a
Met
hod:
Sho
w th
e st
uden
ts p
ictu
res
of a
nim
als
with
pro
tect
ive
part
s su
ch a
s cl
aws,
teet
h, b
eaks
, hoo
ves,
etc
. and
pla
nts
with
sp
ines
and
thor
ns. E
xpla
in h
ow a
nim
als
and
plan
ts u
se d
iffer
ent p
arts
of t
heir
bod
ies
to p
rote
ct th
emse
lves
from
thei
r en
emie
s an
d al
so to
cat
ch p
rey.
Exp
lain
that
all
livin
g th
ings
gro
w a
nd c
hang
e to
sui
t the
ir e
nvir
onm
ent.
The
se c
hang
es a
re c
alle
d ad
apta
tions
. Ada
ptat
ion
mea
ns th
at a
pla
nt o
r an
imal
cha
nges
to fi
t its
env
iron
men
t so
that
it c
an s
urvi
ve. S
peci
es o
f ani
mal
s or
pl
ants
that
can
not a
dapt
will
die
and
may
eve
ntua
lly b
ecom
e ex
tinct
. With
the
help
of p
ictu
res
in th
e bo
ok, d
iscu
ss th
e ki
nds
of
adap
tatio
n in
pla
nts
and
anim
als
livin
g in
diff
eren
t kin
ds o
f env
iron
men
t.
Ask
: Wha
t is
the
mea
ning
of w
arm
-blo
oded
? C
old-
bloo
ded?
Exp
lain
that
ani
mal
s th
at h
ave
a co
nsta
nt b
ody
tem
pera
ture
are
ca
lled
war
m-b
lood
ed. H
uman
bei
ngs,
all
mam
mal
s, a
nd b
irds
are
war
m-b
lood
ed. A
nim
als
who
se b
ody
tem
pera
ture
cha
nges
with
th
e su
rrou
ndin
gs a
re c
alle
d co
ld-b
lood
ed. A
mph
ibia
ns, r
eptil
es, a
nd fi
sh a
re c
old-
bloo
ded.
Col
d-bl
oode
d an
imal
s su
rviv
e lo
w
envi
ronm
enta
l tem
pera
ture
s by
hib
erna
ting.
The
y hi
de in
a w
arm
pla
ce u
ntil
the
tem
pera
ture
bec
omes
war
m.
Dat
e:
Tim
e: 4
0 m
ins
Les
son
plan
47 1
Uni
t: 5
Topi
c: L
ivin
g or
gani
sms
and
thei
r en
viro
nmen
t
Teac
hing
obj
ecti
ves
Lea
rnin
g ou
tcom
es
Stud
ents
sho
uld
be a
ble
to:
Res
ourc
es/M
ater
ials
Act
ivit
ies/
CW
/HW
4.
Food
cha
ins
•to
des
crib
e a
food
ch
ain
•to
exp
lain
the
trop
hic
leve
ls o
f a fo
od c
hain
•to
exp
lain
how
en
ergy
flow
s th
roug
h a
food
cha
in
•to
def
ine
a fo
od w
eb
•de
scri
be a
food
cha
in
•ex
plai
n th
e tr
ophi
c le
vels
of
a fo
od c
hain
•ex
plai
n th
e flo
w o
f en
ergy
thro
ugh
a fo
od
chai
n
•ex
plai
n ho
w fo
od c
hain
s ar
e in
terc
onne
cted
by
food
web
s
Dia
gram
s an
d ch
arts
of
food
cha
ins,
and
food
w
ebs
Ani
mal
pic
ture
s
Rea
ding
: p 4
4, 4
5, 4
6
CW
: Q5
HW
: Q1
(f)
(g)
Key
wor
ds: f
ood
chai
n, c
onsu
mer
, pro
duce
r, he
rbiv
ore,
car
nivo
re, o
mni
vore
, pri
mar
y co
nsum
er, s
econ
dary
con
sum
er,
deco
mpo
ser,
trop
hic
leve
l, py
ram
id o
f num
bers
, foo
d w
eb
Met
hod:
Ask
: Wha
t did
you
eat
for
brea
kfas
t? W
hat i
s br
ead
mad
e fr
om? W
here
doe
s th
e w
heat
for
mak
ing
brea
d co
me
from
? E
xpla
in th
at g
reen
pla
nts
are
prod
ucer
s. T
hey
are
able
to m
ake
thei
r ow
n fo
od u
sing
the
Sun’
s en
ergy
. The
se p
lant
s al
so p
rovi
de
food
for
anim
als.
Ani
mal
s ar
e ca
lled
cons
umer
s of
food
. Som
e an
imal
s ea
t the
fles
h of
oth
er a
nim
als.
The
y ar
e ca
lled
carn
ivor
es.
Ani
mal
s th
at e
at p
lant
s ar
e ca
lled
herb
ivor
es. A
nim
als
that
eat
pla
nts
and
anim
als
are
calle
d om
nivo
res.
Show
the
stud
ents
pi
ctur
es o
f ass
orte
d an
imal
s.
Ask
: Can
you
gue
ss w
hat k
ind
of fo
od e
ach
anim
al e
ats?
Ask
the
stud
ents
to m
ake
a fo
od c
hain
from
the
pict
ures
sho
wn.
Exp
lain
th
at fo
od c
hain
s ar
e in
terl
ocke
d an
d in
terw
oven
like
a s
pide
r’s w
eb. M
any
food
cha
ins
mak
e up
a fo
od w
eb. I
f one
sm
all c
hain
in
the
food
web
bre
aks,
not
muc
h da
mag
e is
don
e, b
ut if
a m
ajor
par
t of t
he c
hain
is b
roke
n, a
lot o
f dam
age
can
occu
r. T
he w
hole
fo
od w
eb c
ould
col
laps
e.
Dra
w a
food
cha
in o
n th
e bo
ard.
Ask
: Whi
ch o
rgan
ism
s ar
e th
e la
rges
t in
num
bers
? Whi
ch o
rgan
ism
s ar
e bi
gges
t in
size
? E
xpla
in th
e py
ram
id o
f num
bers
. The
pos
ition
of a
n or
gani
sm in
a fo
od c
hain
is c
alle
d its
trop
hic
leve
l. A
s en
ergy
flow
s th
roug
h a
food
cha
in,
som
e of
it is
lost
at e
very
leve
l. T
he n
umbe
r of
con
sum
ers
at e
very
trop
hic
leve
l dec
reas
es, w
here
as th
e si
ze o
f the
ani
mal
s in
crea
ses
as
they
con
sum
e m
ore
of th
e or
gani
sms
from
the
leve
l bel
ow th
em. T
he tr
ansf
er o
f ene
rgy
is r
educ
ed a
t eve
ry le
vel,
and
the
amou
nt o
f en
ergy
pas
sed
on to
the
four
th le
vel i
s re
duce
d to
suc
h an
ext
ent t
hat i
t can
not s
uppo
rt a
noth
er p
opul
atio
n of
con
sum
ers.
Dat
e:
Tim
e: 4
0 m
ins
Les
son
plan
481
Uni
t: 5
Topi
c: L
ivin
g or
gani
sms
and
thei
r en
viro
nmen
t
Teac
hing
obj
ecti
ves
Lea
rnin
g ou
tcom
es
Stud
ents
sho
uld
be a
ble
to:
Res
ourc
es/M
ater
ials
Act
ivit
ies/
CW
/HW
5.
Nat
ural
cyc
les
of
elem
ents
•to
exp
lain
the
natu
ral
cycl
es o
f ele
men
ts•
desc
ribe
the
natu
ral c
ycle
s of
ele
men
ts
•ex
plai
n th
eir
role
in th
e en
viro
nmen
t
Dia
gram
s an
d ch
arts
of
the
carb
on c
ycle
, w
ater
cyc
le, n
itrog
en
cycl
e
Rea
ding
: p 4
6, 4
7, 4
8
Act
ivity
: Dra
w
diag
ram
s of
the
wat
er
cycl
e an
d th
e ni
trog
en
cycl
e.
CW
: Q4
Key
wor
ds: n
atur
al c
ycle
, wat
er c
ycle
, nitr
ogen
cyc
le, n
itrog
en-f
ixin
g ba
cter
ia, n
itrat
e, p
lant
pro
tein
, ani
mal
pro
tein
, den
itrify
ing
bact
eria
, car
bon
cycl
e, c
arbo
n di
oxid
e
Met
hod:
Ask
: How
muc
h ox
ygen
, nitr
ogen
, car
bon
diox
ide
and
wat
er v
apou
r ar
e th
ere
in th
e at
mos
pher
e? W
hat d
o liv
ing
thin
gs
use
oxyg
en fo
r? W
hat d
o liv
ing
thin
gs u
se c
arbo
n di
oxid
e fo
r? W
hat d
o liv
ing
thin
gs u
se n
itrog
en fo
r? H
ow d
o w
e us
e w
ater
? H
ow
does
the
leve
l of a
ll th
ese
subs
tanc
es r
emai
n co
nsta
nt in
the
atm
osph
ere?
How
are
they
rep
lace
d?
Exp
lain
the
natu
ral c
ycle
s of
car
bon,
nitr
ogen
, and
wat
er w
ith th
e he
lp o
f dia
gram
s an
d ch
arts
.
Dat
e:
Tim
e: 4
0 m
ins
Les
son
plan
49 1
Unit 5: Living organisms and their environment Worksheet 1
Name: Date:
1. Fill in the spaces on the diagram to describe the nitrogen cycle:
2. Use the following food chains to make a food web:
grass grasshopper praying mantis eagle
grass beetle frog snake eagle
grass beetle sparrow eagle
From your food web, write the names of:
a producer
primary consumers , ,
secondary consumers , ,
a tertiary consumer
Photocopiable material
501
Unit 5: Living organisms and their environment Worksheet 2
Name: Date:
Q. Fill in the blanks to complete the description of the flow of energy through food chains.
The position of an organism in a food chain is called its . Green plants
usually occupy the trophic level. The second trophic level is occupied
by . The third trophic level is occupied by .
Most food chains do not have more than trophic levels, because
is lost at each level and cannot be passed on to the next level. Some of
this is lost as and some of the food that is eaten remains undigested.
The amount of energy at the fourth trophic level is reduced to such an extent that it cannot
support another population of .
In a food chain, organisms at the base are in size, but
in number, while the successive groups of consumers show a
progressive in size and a in number. This
relationship can be represented by a chart known as the of numbers.
Photocopiable material
51 1
Teaching objectives:• to explain the occurrence of water in nature• to explain the chemical nature of water• to explain the water cycle• to explain the states in which water exists and describe how water changes its states• to explain the test for the purity of water• to describe the types of water and discuss why hard water is harmful• to describe the properties of pure water• to describe the impurities found in water and explain how drinking water is purified• to explain how water is distilled in the laboratory• to explain how water becomes polluted and the harmful effects of water pollution
Teaching strategy:Ask: What is water? How do we use water? From where do we get water? How does water reach a well? Explain the occurrence of natural water. Write the chemical formula of water on the board. Explain that it is made up of two gases, hydrogen and oxygen. Ask: What impurities are found in river water? How do these impurities reach river water? Explain how harmful substances flow in the river water and reach the sea. Ask: How do fish breathe? From where do aquatic animals get oxygen? Explain that oxygen dissolves in water, and is used by fish and aquatic animals.
Wipe the board with a wet sponge. Ask: How long will the board stay wet? Will the board dry by itself? Does it have to be wiped dry? Where will the water on the board go? Can you see the water as it leaves the board? Explain that when the water goes into the air it is called water vapour. Water vapour is invisible. The process of water going into the air is called evaporation. Ask: Where does the water from puddles go after a rain? How do wet clothes become dry? Place some ice cubes into a glass or an empty tin can. Add some water, so that the glass or can is 3/4 full. Let it stand for about ten minutes. Ask: What can you see on the outside of the glass or can? Where did the water come from? Explain that the water droplets came from the air. Air contains a lot of vapours that we cannot see. It is called water vapour. When water vapour condenses into droplets we can see it. This process is called condensation.
Tell the children you’re going to make rain. Pour a cup of very hot water into a large empty pyrex jar to make a lot of steam. Place a tin can filled with ice cubes on top of the jar. Ask: What can you see inside the jar? Explain that the heat inside the jar warms the air. The warm moist air in the jar begins to look like steam. The steam condenses and turns into water vapour. As the droplets of water become larger and heavier they form a cloud. Large droplets form on the cold bottom of the tin can. They will begin to roll down the sides of the jar or just drop as rain.
Water
UNIT 6
521
Show the students the water cycle chart. Explain the water cycle. Ask: What happens to the water in the oceans? Where does the water in the oceans come from? What happens to the water when it evaporates? Does new water fall from the sky or is it the same water that fell before? Put some ice cubes in a beaker. Take the temperature of the ice cubes. Write it on the board. Heat the water. Take the temperature of the liquid water, when it begins to boil. Write it on the board. Ask: What can you see in the beaker? Explain the change of state due to heat, and the freezing and boiling points. Hold a cold saucer over the steam coming from the boiling water. Ask: What is happening? Explain the process of condensation and evaporation.
Ask: What do you think will happen to the boiling point of water if we add some salt to the water? Explain that impurities lower the boiling point. Take some copper sulphate crystals in a china dish. Show the students the blue colour of the crystals. Heat the dish. The copper sulphate crystals will crumble to a white powder. Show it to the students. Now add a drop of distilled water to the white powder. The blue colour will reappear. Explain that this is a test for water. Ask: Have you been to a hill station? What happens when you rub soap on your hands to wash? Explain that water which does not form lather with soap is called hard water. Hardness of water is due to some chemicals dissolved in the water. As rainwater passes through rocks, some chemicals get dissolved in it, which make the water hard. Explain that one way to make hard water soft is by boiling it.
Ask: How can we clean dirty water? Demonstrate and explain filtration of muddy water. Also explain the purification of drinking in a filtration plant by a chart. Explain the process of distillation with the help of a chart. Ask: Will distilled water have impurities in it? Why? How do we use water? In what other ways is water used? Explain the uses of water. Discuss water pollution in the class. Explain that when water is polluted, the animals that drink the polluted water become sick, and sometimes die. If water is filtered and then dumped into rivers and lakes, it helps keep the water cleaner. Oil spills in the ocean kills birds, fish, and plants. Discuss ways in which we can improve the environment and reduce pollution.
Summarize the lesson.
Answers to Exercises in Unit 61. (a) Water is a compound of oxygen and hydrogen. Its chemical formula is H2O.
(b) Fish and other water animals can breathe in water because it contains dissolved air.
(c) Pure water boils at 100°C and freezes at 0°C at normal atmospheric pressure. Pure water turns white copper sulphate powder blue.
(d) Hard water does not form lather with soap easily.
(e) Hardness of water is due to some chemicals that get dissolved in rainwater when it falls on rocks.
(f) Properties of pure water:
(i) It has no colour, taste, or smell.
(ii) It freezes at 0°C.
(iii) It boils at 100°C.
Unit 6 Water
53 1
Amazing Science TG 7
(iv) It is a bad conductor of electricity.
(v) It is a very good solvent.
(vi) It reacts with many metals and non-metals.
(g) The common impurities in water are: bacteria, mud, sand, mineral salts, and the remains of dead plants and animals.
(h) Water can be purified in the laboratory by distillation in an apparatus called a Liebig condenser.
(i) Water becomes polluted by:
(i) dirty water from our houses and farms
(ii) liquid wastes from factories
(iii) oil spills from oil tankers in the seas
2. (a) 3/4 (b) H2O (c) taste, smell (d) filtration
(e) Chlorine (f) Soft (g) chemicals (h) boiling
3. Unwanted and harmful substances in the water cause water pollution. Dirty water from our houses and farms contains germs that can cause diseases in humans and animals. If this water drains into a river, the river water becomes polluted. Waste liquid from factories is dumped into rivers. It contains dangerous chemical substances which may not kill fish but are stored in their bodies. They can poison humans if they eat them.
Oil pollution is caused by oil spills from oil tankers at sea. It kills seabirds by poisoning them and by clogging up their wings, so that they cannot fly to find food. Oil also kills all forms of life on rocks, in the mud, and on beaches.
4. Refer to Pupil’s Book.
Additional Exercise
MCQs
(a) The boiling point of pure water in degrees Centigrade is .
0 50 100 [100]
(b) Green plants need water for .
digestion respiration photosynthesis [photosynthesis]
(c) Water becomes hard due to the presence of dissolved .
sand rock chemicals [chemicals]
(d) Chlorine is added to water in a water purification plant to .
kill germs remove hardness filter it [kill germs]
541
(e) What percentage of water covers the Earth? .
50% 75 % 100 % [75%]
(f) The purest form of water is .
drain water sea water rain water [rain water]
(g) Unwanted and harmful substances in the water cause .
air pollution water pollution land pollution [water pollution]
(h) Which kind of pollution is harmful for marine life in the sea? .
Oil pollution Air pollution Land pollution [Oil pollution]
(i) The movement of water between the sea, the land, and the atmosphere is called .
hydrogen cycle oxygen cycle water cycle [water cycle]
(j) Water can be purified in the laboratory by a process called .
filtration distillation evaporation [distillation]
Unit 6 Water
55 1
Uni
t: 6
Topi
c: W
ater
Teac
hing
obj
ecti
ves
Lea
rnin
g ou
tcom
es
Stud
ents
sho
uld
be a
ble
to:
Res
ourc
es/M
ater
ials
Act
ivit
ies/
CW
/HW
1.
Wat
er
•to
exp
lain
wha
t co
nstit
utes
wat
er
•to
exp
lain
the
wat
er c
ycle
•to
exp
lain
the
prop
ertie
s of
pur
e w
ater
•ex
plai
n th
e oc
curr
ence
of
wat
er
•st
ate
the
chem
ical
fo
rmul
a of
wat
er
•ex
plai
n th
e w
ater
cyc
le
•lis
t the
pro
pert
ies
of
pure
wat
er
•te
st th
e pu
rity
of w
ater
Cha
rts
of th
e w
ater
cy
cle,
dia
gram
of
the
wat
er m
olec
ule,
be
aker
, bur
ner,
stan
d,
ther
mom
eter
Rea
ding
: p 5
3, 5
4
Act
ivity
: 1
Exp
erim
ent:
Tes
t for
pu
re w
ater
[p
53]
CW
: Q1
(a)
(b)
HW
: Q1
(f)
Key
wor
ds: w
ater
, hyd
roge
n, o
xyge
n, w
ater
cyc
le, p
rope
rty,
cop
per
sulp
hate
Met
hod:
Ask
: Wha
t is
wat
er?
How
do
we
use
wat
er?
Fro
m w
here
do
we
get w
ater
? H
ow d
oes
wat
er r
each
a w
ell?
Exp
lain
the
occu
rren
ce o
f nat
ural
wat
er. W
rite
the
chem
ical
form
ula
of w
ater
on
the
boar
d. E
xpla
in it
s co
mpo
sitio
n. A
sk: W
hat i
mpu
ritie
s ar
e fo
und
in r
iver
wat
er?
How
do
thes
e im
puri
ties
reac
h th
e ri
vers
? E
xpla
in h
ow h
arm
ful s
ubst
ance
s fr
om o
ur h
omes
, far
ms,
and
fa
ctor
ies
flow
into
the
rive
r an
d th
en r
each
the
sea.
Ask
: How
do
fish
brea
the?
Fro
m w
here
do
aqua
tic a
nim
als
get o
xyge
n? E
xpla
in th
at o
xyge
n is
slig
htly
sol
uble
in w
ater
and
is u
sed
by fi
sh a
nd o
ther
wat
er a
nim
als.
Show
the
stud
ents
a d
iagr
am o
f the
wat
er c
ycle
. Exp
lain
how
wat
er is
rec
ycle
d in
nat
ure.
Put
som
e ic
e cu
bes
in a
bea
ker.
Rec
ord
the
tem
pera
ture
of t
he ic
e cu
bes.
Hea
t the
ice
until
it tu
rns
into
wat
er a
nd s
tart
s bo
iling
. Rec
ord
the
tem
pera
ture
of t
he b
oilin
g w
ater
. Ask
: Wha
t do
you
thin
k w
ill h
appe
n to
the
boili
ng p
oint
of w
ater
if w
e ad
d so
me
salt
to it
? E
xpla
in th
at im
puri
ties
in w
ater
lo
wer
the
boili
ng p
oint
. Des
crib
e th
e pr
oper
ties
of p
ure
wat
er.
Des
crib
e th
e te
sts
for
pure
wat
er a
nd p
erfo
rm th
e ex
peri
men
ts o
n pa
ges
53 a
nd 5
8.
Dat
e:
Tim
e: 4
0 m
ins
Les
son
plan
561
Uni
t: 6
Topi
c: W
ater
Teac
hing
obj
ecti
ves
Lea
rnin
g ou
tcom
es
Stud
ents
sho
uld
be a
ble
to:
Res
ourc
es/M
ater
ials
Act
ivit
ies/
CW
/HW
2.
Typ
es o
f wat
er
•to
des
crib
e ty
pes
of w
ater
•to
exp
lain
the
caus
es o
f ha
rdne
ss o
f wat
er
•id
entif
y di
ffere
nt ty
pes
of
wat
er
•ex
plai
n th
e ca
uses
of h
ard
wat
er
Dia
gram
s an
d ch
arts
of
har
d an
d so
ft w
ater
Rea
ding
: p 5
4, 5
5
CW
: Q2
HW
: Q1
(d)
(e)
Key
wor
ds: s
oft
wat
er, h
ard
wat
er, t
empo
rary
har
dnes
s, p
erm
anen
t ha
rdne
ss, c
alci
um h
ydro
gen
carb
onat
e, li
mes
tone
, cha
lk,
calc
ium
car
bona
te
Met
hod:
Ask
: Hav
e yo
u be
en t
o a
hill
stat
ion?
Wha
t ha
ppen
s w
hen
you
rub
soap
on
your
han
ds t
o w
ash
them
? E
xpla
in t
hat
wat
er w
hich
doe
s no
t fo
rm la
ther
with
soa
p is
cal
led
hard
wat
er. T
he h
ardn
ess
of w
ater
is c
ause
d by
som
e ch
emic
als
diss
olve
d in
it. A
s ra
inw
ater
pas
ses
thro
ugh
rock
s so
me
chem
ical
s di
ssol
ve in
it w
hich
mak
es t
he w
ater
har
d. E
xpla
in t
he d
iffer
ent
type
s of
ha
rd w
ater
. Exp
lain
tha
t on
e w
ay t
o m
ake
hard
wat
er s
oft
is b
y bo
iling
it. P
erm
anen
t ha
rdne
ss c
an b
e re
mov
ed b
y ad
ding
ch
emic
als
to h
ard
wat
er t
o m
ake
it so
ft.
Dat
e:
Tim
e: 4
0 m
ins
Les
son
plan
57 1
Uni
t: 6
Topi
c: W
ater
Teac
hing
obj
ecti
ves
Lea
rnin
g ou
tcom
es
Stud
ents
sho
uld
be a
ble
to:
Res
ourc
es/M
ater
ials
Act
ivit
ies/
CW
/HW
3.
Impu
ritie
s in
wat
er•
to d
escr
ibe
the
impu
ritie
s in
wat
er
•to
exp
lain
the
way
s by
whi
ch w
ater
can
be
pur
ified
•de
scri
be t
he im
puri
ties
in
wat
er
•de
scri
be t
he m
etho
ds b
y w
hich
wat
er c
an b
e pu
rifie
d
Cha
rts
and
diag
ram
s of
a w
ater
filt
ratio
n pl
ant,
a L
eibi
g co
nden
ser,
a r
ound
bo
ttom
fla
sk, a
th
erm
omet
er, a
co
nica
l fla
sk
Rea
ding
: p 5
5, 5
6
Act
ivity
: 2, 3
CW
: Q4
HW
: Q1
(g)
(h)
Key
wor
ds: b
acte
rium
, min
eral
sal
t, di
still
atio
n, L
eibi
g co
nden
ser,
sed
imen
tatio
n ta
nk, c
hlor
ine,
pum
p, s
tora
ge t
ank,
fil
trat
ion
plan
t
Met
hod:
Ask
: How
can
dir
ty w
ater
be
puri
fied?
Dem
onst
rate
the
filt
ratio
n of
mud
dy w
ater
in t
he la
bora
tory
. Set
up
the
appa
ratu
s us
ed f
or d
istil
latio
n in
the
labo
rato
ry a
nd d
escr
ibe
the
proc
ess.
Exp
lain
tha
t di
still
ed w
ater
is t
he p
ures
t fo
rm o
f w
ater
. It
is p
rodu
ced
by t
he p
roce
ss o
f ev
apor
atio
n an
d co
nden
satio
n, r
athe
r lik
e th
e w
ater
cyc
le. R
ainw
ater
is a
lso
the
pure
st
natu
ral f
orm
of
wat
er, b
ut it
bec
omes
impu
re a
s it
pass
es t
hrou
gh t
he a
tmos
pher
e w
here
gas
es, s
mok
e, d
ust
part
icle
s, a
nd
bact
eria
get
mix
ed w
ith it
.
Show
the
stu
dent
s a
diag
ram
of
a fil
trat
ion
plan
t. E
xpla
in t
hat
the
wat
er t
hat
reac
hes
our
hom
es is
filt
ered
and
cle
aned
in a
fil
trat
ion
plan
t.
Dat
e:
Tim
e: 4
0 m
ins
Les
son
plan
581
Uni
t: 6
Topi
c: W
ater
Teac
hing
obj
ecti
ves
Lea
rnin
g ou
tcom
esSt
uden
ts s
houl
d be
abl
e to
:R
esou
rces
/Mat
eria
lsA
ctiv
itie
s/C
W/H
W
4.
Use
s of
wat
er
W
ays
to r
educ
e w
asta
ge o
f w
ater
W
ater
pol
lutio
n
•to
iden
tify
the
uses
of
wat
er
•to
dis
cuss
way
s to
sav
e w
ater
•to
exp
lain
wat
er
pollu
tion
•id
entif
y th
e w
ays
we
use
wat
er
•ex
plai
n w
hy w
e m
ust
save
wat
er a
nd s
ugge
st
way
s of
doi
ng s
o
•ex
plai
n ho
w w
ater
po
llutio
n is
cau
sed
and
asse
ss it
s im
pact
Cha
rts
and
diag
ram
s of
the
use
s of
wat
er,
wat
er p
ollu
tion
Rea
ding
: p 5
6, 5
7
CW
: Q1
(i)
HW
: Q1
Q
3
Key
wor
ds: u
se, w
asta
ge, w
ater
pol
lutio
n
Met
hod:
Ask
: Will
dis
tille
d w
ater
con
tain
impu
ritie
s ? W
hy?
How
do
we
use
wat
er?
In w
hat
othe
r w
ays
is w
ater
use
d?
Dis
cuss
the
dom
estic
and
com
mer
cial
use
s of
wat
er. D
iscu
ss w
ater
pol
lutio
n. E
xpla
in t
hat
whe
n w
ater
bec
omes
pol
lute
d it
can
mak
e an
imal
s an
d hu
man
bei
ngs
sick
. If
wat
er is
filt
ered
and
the
n du
mpe
d in
to r
iver
s an
d la
kes,
it h
elps
to
keep
the
w
ater
cle
aner
. Oil
spill
s in
the
oce
an k
ill b
irds
, fis
h, a
nd p
lant
s. D
iscu
ss t
he w
ays
in w
hich
wat
er p
ollu
tion
can
be r
educ
ed
and
the
way
s in
whi
ch w
e ca
n re
duce
pol
lutio
n an
d im
prov
e th
e en
viro
nmen
t.
Dat
e:
Tim
e: 4
0 m
ins
Les
son
plan
59 1
Unit 6: Water Worksheet 1
Name: Date:
Q. Underline the correct word(s) in the sentences below.
a. Water is a chemical / physical substance which is found in abundance on the Earth.
b. Two-thirds / three-quarters of the Earth’s surface is covered with water.
c. Water is a combination of hydrogen and oxygen / hydrogen and nitrogen.
d. Rainwater is the dirtiest / purest form of natural water.
e. When water falls through the atmosphere many gases / solids are dissolved in it.
f. As rainwater sinks into the ground, it dissolves many minerals / gases.
g. Sea water / River water contains a lot of suspended and dissolved impurities and is therefore unfit for drinking.
h. Fresh water contains dissolved air / dust particles, which are used by water plants and animals for breathing.
Photocopiable material
601
Unit 6: Water Worksheet 2
Name: Date:
1. Explain how water is used:
a. by animals and plants
b. by human beings
c. in industry
d. in agriculture
e. for generating electricity
f. for travel and transport
2. List five ways in which water becomes polluted.
Photocopiable material
61 1
Teaching objectives:• to explain the structure of an atom• to explain the difference between atomic number and mass number• to describe the atomic configuration of the first 18 elements in the periodic table• to define valency• to explain the formation of ions• to describe isotopes and explain their uses• to explain the formation of ionic and covalent bonds• to explain the types and number of elements in simple molecules and compounds• to explain the chemical formulae of some compounds• to explain the law of constant composition and verify it, using examples
Teaching strategy:Draw an atom on the board. Ask the students what they know about an atom? What is everything around us made of? Explain the composition of matter and describe the structure of an atom. Every atom is thought to be made up of a nucleus containing protons and neutrons. The nucleus is surrounded by a cloud of electrons. Protons carry a positive charge; electrons carry a negative charge while neutrons do not have any charge. Explain the distribution of electrons in the various shells of an atom.
Ask: How can you write your name in shorthand? Explain that a symbol is a way of writing the names of symbols in shorthand. Discuss the various ways in which symbols can be written. Also discuss the Latin and Greek names of elements and their symbols.
Ask: What happens when lots of atoms of the same kind join up? Explain the structure of elements as being made up of the same kind of atom. Show the students samples of different elements. Ask them to name some elements. Draw the atomic model on the board and explain the different particles and the charges on them. Explain the distribution of electrons in the shells and how ions are formed when electrons are given or taken by atoms. Ask the students to draw diagrams showing the structures of some atoms. Explain what atomic number and mass number mean. Discuss the formation of ionic and covalent bonds.
Ask: What will happen to a piece of coal if we keep on pounding it? Explain that the smallest particle that you get will still be coal or to be more exact carbon. Discuss what an element is and display a chart of the first twenty elements of the periodic table and ask the students to write the number of proton, electrons, neutrons, and the mass number of each element. Discuss isotopes as being heavier atoms of certain elements. Discuss how isotopes are useful in experiments and
Composition of matter
UNIT 7
621
diagnosis of diseases. Ask: What is a compound? Discuss the formation of compounds on the basis of joining up of atoms. Explain valency as the combining capacity of atoms to make compounds. Discuss the types of bonds that help to make compounds. Explain the methods of writing formulae of compounds.
Summarize the lesson.
Answers to Activities
1. Compound Atoms in it Formula Ratio of the atoms
carbon dioxide carbon, oxygen CO2 1:2
ammonia nitrogen, hydrogen NH3 1:3
sodium chloride sodium, chlorine NaCl 1:1
calcium oxide calcium, oxygen CaO 1:1
methane carbon, hydrogen CH4 1:4
2. Element Number of electrons in each shell
1st 2nd 3rd 4th
hydrogen 1 - - -
carbon 2 4
nitrogen 2 5 - -
oxygen 2 6 - -
sodium 2 8 1 -
magnesium 2 8 2 -
aluminium 2 8 3 -
chlorine 2 8 7 -
potassium 2 8 8 1
calcium 2 8 8 2
4. (a) A B E (b) D (c) C (d) B E
(e) A magnesium B Isotope of magnesium C magnesium positive Ion D oxygen negative ion E isotope of flourine
5. (a) The gas is ammonia. (b) Its formula is NH3. (c) Covalent bond (d) Water
Unit 7 Composition of matter
63 1
Amazing Science TG 7
Answers to Exercises in Unit 71. (a) An atom is made up of tiny particles called electrons, protons, and neutrons. Electrons are
negatively charged particles that revolve around the nucleus in a specific path called an orbit. Protons are positively charged particles found in the nucleus of an atom. Neutrons are neutral particles which are also present in the nucleus. The mass of a neutron is equal to the mass of a proton.
(b) (i) An element is a substance that is made up of the same kinds of atoms. For example, the element carbon is made up of carbon atoms only.
(ii) C, N, H, O, S, P, Ca, Cl
(iii) Scientists sometimes call the valency the ‘combining power’ of an element. Depending on the arrangement of electrons around a nucleus, atoms of different elements may tend to ‘lose’ or ‘gain’ electrons. If this tendency is strong, then the element is reactive or unstable. If it is weak, the element is unreactive or stable.
The valency of an element depends on the number of electrons the element has in its outermost shell. If an element has four or fewer electrons in its outer shell, then the number of electrons is the same as the valency. If the element has more than four electrons, its valency is eight minus the number of electrons.
(c) When two or more atoms combine chemically, they form a compound. For example, hydrogen and oxygen combine chemically to form water.
2. (a) Ionic bond
(b) Covalent bond
3. (a) atoms (b) Protons (c) electron (d) atomic number (e) mass number (f) 2 (g) 8 (h) chemical bond (i) positive
4. (a) The proton is a positively charged particle which is present in the nucleus of an atom.
An electron is a negatively charged particle which revolves around the nucleus of an atom in a specific path called an orbit.
(b) The chemical names of elements written in abbreviated form are called symbols; usually the first letter or the first two letters of the name of the element are used. Sometimes the first or the first two letters of the Latin or Greek names of elements are used.
The molecule of a substance written in symbols is called a chemical formula.
(c) The number of protons in an atom is called is atomic number. The oxygen atom has 8 protons so its atomic number is 8.
The sum of the number of protons and neutrons in an atom is called its mass number or atomic mass. A carbon atom has 6 neutrons and 6 protons, so its mass number is 12.
(d) An atom is a tiny indivisible particle of which all matter is composed. It is made up protons, neutrons, and electrons.
A molecule is made up of two or more than two atoms which are held together by chemical bonds. The atoms in a molecule may be of the same or of different elements joined together.
641
(e) An element is a substance that is made of only one kind of atom. Sodium is made of sodium atoms only so it is an element. Carbon, mercury, iron, copper, etc. are all elements. Altogether 117 different elements are known. Of these, 90 have been obtained from the Earth’s crust and atmosphere, and 23 have been artificially made by scientists.Every element has a name and a symbol.
A compound is formed when two or more atoms join together in a chemical reaction. The atoms from the elements are held together by forces which scientists call chemical bonds.Water is a compound. It is made up of water molecules. In the same way sodium chloride (common salt) is formed by the joining up of sodium and chloride ions.
(f) In an ionic bond, the electrons are either given to or received from atoms. The atoms become charged particles called ions. When an atom gives away electrons it becomes a positive ion. When an atom receives electrons it becomes a negative ion. Ions are held together by electrostatic forces
When two atoms react together and both of them need to gain electrons in order to reach the number of electrons to complete their outer shells, they do so by sharing electrons between them.
Because the atoms share electrons, there is a strong force of attraction between them. This force is called a covalent bond. The bonded atoms form a molecule.
(g) Refer to (b)
(h) An element is a substance that is made of only one kind of atom. Sodium is made of sodium atoms only so it is an element. Carbon, mercury, iron, copper, etc. are all elements. Altogether 117 different elements are known. Of these, 90 have been obtained from the Earth’s crust and atmosphere, and 23 have been artificially made by scientists.
Atoms of one element all have the same number of protons and electrons but they do not necessarily have the same number of neutrons. Atoms of the same element, with the same number of protons but different numbers of neutrons are called ‘isotopes’ of that element. They behave in an unusual way that has nothing to do with their electrons. Most elements have more than one isotope, chlorine has two, carbon has three isotopes.
5. Individual work
6. Plants absorb some carbon-14 atoms from the carbon dioxide in the air during the process of photosynthesis. When a plant or animal dies it takes in no more carbon atoms. The carbon-14 atoms in it slowly decay. By measuring the radiation from them, the age of the dead remains can be worked out.
7, 8, 9 Individual work
10. Latin names Symbols Cuprum Cu Argentum Ag Aurum Au Hydrargyrum Hg Ferrum Fe Kalium K Natrium Na Plumbum Pb Stannum Sn
Unit 7 Composition of matter
65 1
Amazing Science TG 7
Additional Exercise
MCQs
(a) The nucleus of an atom contains .
electrons and neutrons protons and electrons protons and neutrons
[protons and neutrons]
(b) Electrons in an atom have .
a positive charge negative charge no charge [negative charge]
(c) The number of protons in an atom is called .
atomic number mass number electronic number [atomic number]
(d) The number of electrons in an atom is the number of protons.
greater than equal to less than [equal to]
(e) A molecule is composed of two or more .
electrons protons atoms [atoms]
(f) A compound is formed when two or more atoms are combined .
physically chemically electronically [chemically]
(g) Isotopes are atoms of the same element.
heavier lighter equal [heavier]
(h) is the combining power of an atom.
Tendency Valency Accuracy [Valency]
(i) The name of a chemical compound written in symbols is called .
chemical equation chemical reaction chemical formula
[chemical formula]
(j) We can find out the of a compound by the number of atoms and their ratios.
formula name valency [formula]
661
Uni
t: 7
Topi
c: C
ompo
siti
on
of m
atte
r
Teac
hing
obj
ecti
ves
Lea
rnin
g ou
tcom
es
Stud
ents
sho
uld
be a
ble
to:
Res
ourc
es/M
ater
ials
Act
ivit
ies/
CW
/HW
1.
Stru
ctur
e of
an
atom
•
to d
escr
ibe
the
stru
ctur
e of
an
atom
•to
exp
lain
the
dist
ribu
tion
of
elec
tron
s in
an
atom
•to
exp
lain
ato
mic
nu
mbe
r an
d m
ass
num
ber
•de
scri
be th
e st
ruct
ure
of
an a
tom
•ex
plai
n th
e di
stri
butio
n of
ele
ctro
ns in
an
atom
•de
fine
mas
s nu
mbe
r an
d at
omic
num
ber
Dia
gram
s an
d ch
arts
of
ato
ms
Rea
ding
: p 6
1, 6
2, 6
3
Act
ivity
: 2
CW
: Q5
HW
: Q1
(a)
(b)
Q
9
Key
wor
ds: a
tom
, ele
ctro
n, p
roto
n, n
eutr
on, n
ucle
us, a
tom
ic m
ass
unit
Met
hod:
Dra
w a
dia
gram
of a
n at
om o
n th
e bo
ard.
Ask
the
stud
ents
wha
t the
y kn
ow a
bout
an
atom
.
Des
crib
e th
e st
ruct
ure
of a
n at
om. E
very
ato
m is
thou
ght t
o be
mad
e up
of a
nuc
leus
con
tain
ing
prot
ons
and
neut
rons
. The
nu
cleu
s is
sur
roun
ded
by a
clo
ud o
f ele
ctro
ns. P
roto
ns c
arry
a p
ositi
ve c
harg
e, e
lect
rons
car
ry a
neg
ativ
e ch
arge
, whi
le th
e ne
utro
ns d
o no
t hav
e an
y ch
arge
on
them
. Exp
lain
the
arra
ngem
ent o
f ele
ctro
ns in
the
vari
ous
shel
ls o
f an
atom
, usi
ng th
e fo
rmul
a 2n
2 , w
here
‘n’ i
s th
e nu
mbe
r of
the
shel
l. eg
. Fir
st s
hell
: 2 x
12 =
2 e
lect
rons
Se
cond
she
ll : 2
x 2
2 =
8 e
lect
rons
T
hird
she
ll : 2
x 3
2 = 1
8 el
ectr
ons,
a
nd s
o on
.
T
he la
st s
hell
can
hold
onl
y up
to e
ight
ele
ctro
ns. H
elp
the
stud
ents
to p
ract
ice
draw
ing
the
elec
tron
ic c
onfig
urat
ion
of
diffe
rent
ato
ms.
Exp
lain
that
the
dist
ribu
tion
of e
lect
rons
in th
e va
riou
s sh
ells
of a
n at
om is
cal
led
its e
lect
roni
c co
nfig
urat
ion.
Dra
w a
sod
ium
ato
m o
n th
e bo
ard.
Exp
lain
that
the
num
ber
of p
roto
ns in
an
atom
is c
alle
d its
ato
mic
num
ber,
whe
reas
the
sum
of
the
prot
ons
and
neut
rons
in th
e at
om is
cal
led
its a
tom
ic m
ass.
Exp
lain
the
way
s of
wri
ting
the
atom
ic n
umbe
r an
d th
e at
omic
m
ass
of a
n at
om.
Dat
e:
Tim
e: 4
0 m
ins
Les
son
plan
67 1
Uni
t: 7
Topi
c: C
ompo
siti
on
of m
atte
r
Teac
hing
obj
ecti
ves
Lea
rnin
g ou
tcom
es
Stud
ents
sho
uld
be a
ble
to:
Res
ourc
es/M
ater
ials
Act
ivit
ies/
CW
/HW
2.
Ele
men
ts
•to
def
ine
an e
lem
ent
•to
exp
lain
the
sym
bols
, and
the
num
ber
of p
artic
les
in a
tom
s
•to
def
ine
isot
opes
•to
exp
lain
the
uses
of
rad
iatio
n
•de
fine
an e
lem
ent
•w
rite
the
sym
bols
, at
omic
num
ber,
and
mas
s nu
mbe
r of
ato
ms
and
be a
ble
to d
raw
di
agra
ms
of th
em
•ex
plai
n w
hat i
soto
pes
are
and
list t
he u
ses
of
radi
atio
n
A c
hart
of t
he fi
rst
twen
ty e
lem
ents
of t
he
peri
odic
tabl
e
Rea
ding
: p 6
3, 6
4
Act
ivity
: 3
CW
: Q1
(b)
(i)
(ii)
HW
: Q6,
Q10
Key
wor
ds: e
lem
ent,
deca
y, is
otop
e, r
adia
tion
Met
hod:
Ask
: Can
you
wri
te y
our
nam
e in
sho
rtha
nd?
Exp
lain
that
a s
ymbo
l is
a sh
orth
and
way
of w
ritin
g th
e na
me
of a
n el
emen
t. D
iscu
ss th
e va
riou
s w
ays
in w
hich
sym
bols
can
be
wri
tten
. Als
o di
scus
s th
e L
atin
and
Gre
ek n
ames
of e
lem
ents
and
thei
r sy
mbo
ls.
Ask
: Wha
t hap
pens
whe
n lo
ts o
f ato
ms
of th
e sa
me
kind
join
up?
Exp
lain
that
ele
men
ts a
re m
ade
up o
f the
sam
e ki
nd o
f ato
m.
Show
the
stud
ents
the
char
t of t
he fi
rst t
wen
ty e
lem
ents
of t
he p
erio
dic
tabl
e an
d di
scus
s th
eir
atom
ic s
truc
ture
s.
Ask
: Wha
t is
an is
otop
e? E
xpla
in th
at a
tom
s ar
e no
t alw
ays
iden
tical
. Ato
ms
havi
ng th
e sa
me
num
ber
of p
roto
ns a
nd e
lect
rons
, bu
t diff
eren
t num
bers
of n
eutr
ons
are
calle
d is
otop
es o
f tha
t ele
men
t. T
hey
beha
ve d
iffer
ently
from
the
norm
al a
tom
s of
the
sam
e el
emen
t. D
iscu
ss th
e be
havi
ours
of i
soto
pes
and
the
proc
ess
of d
ecay
in th
e ca
rbon
-14
isot
ope.
Car
bon-
14 is
sai
d to
be
radi
oact
ive.
Whe
n it
deca
ys it
giv
es o
ut r
adia
tion
from
its
nucl
eus.
Dis
cuss
the
uses
of r
adia
tion.
Dat
e:
Tim
e: 4
0 m
ins
Les
son
plan
681
Uni
t: 7
Topi
c: C
ompo
siti
on
of m
atte
r
Teac
hing
obj
ecti
ves
Lea
rnin
g ou
tcom
es
Stud
ents
sho
uld
be a
ble
to:
Res
ourc
es/M
ater
ials
Act
ivit
ies/
CW
/HW
3.
Vale
ncy
Fo
rmat
ion
of io
ns
•to
exp
lain
val
ency
•
to e
xpla
in h
ow io
ns
are
form
ed
•ex
plai
n va
lenc
y
•de
scri
be th
e fo
rmat
ion
of io
ns
Dia
gram
s of
the
stru
ctur
e of
ato
ms,
ta
ble
of v
alen
cies
of
atom
s
Rea
ding
: p 6
5, 6
6
Act
ivity
: 4
CW
: Q3
HW
: Q1
(b)
(iii)
, Q7
Key
wor
ds: v
alen
cy, i
on, c
atio
n, a
nion
, ion
ic b
ond
Met
hod:
Ask
: How
do
atom
s jo
in u
p w
ith e
ach
othe
r? E
xpla
in th
at th
e co
mbi
ning
pow
er o
f an
elem
ent i
s ca
lled
its v
alen
cy. T
he
vale
ncy
of a
n el
emen
t dep
ends
on
the
num
ber
of e
lect
rons
in th
e ou
term
ost s
hell
of a
n at
om. W
ith e
xam
ples
of e
lem
ents
in th
e pe
riod
ic ta
ble,
exp
lain
the
vale
ncy
of e
lem
ents
. If a
n at
om h
as o
ne e
lect
ron
in it
s ou
term
ost s
hell
its v
alen
cy is
1+
. If a
n at
om h
as
7 el
ectr
ons
its v
alen
cy is
1-
beca
use
it is
one
ele
ctro
n sh
ort o
f the
8 e
lect
rons
that
an
atom
can
hol
d in
its
oute
rmos
t she
ll. D
iscu
ss
how
val
ency
can
be
used
to w
ork
out t
he c
hem
ical
form
ulae
of c
ompo
unds
.
Ask
: Wha
t is
an io
n? E
xpla
in th
at w
hen
atom
s lo
se o
r ga
in e
lect
rons
, ion
s ar
e fo
rmed
. With
dia
gram
s on
the
boar
d ex
plai
n ho
w
nega
tive
and
posi
tive
ions
are
form
ed. N
egat
ive
ions
are
cal
led
anio
ns a
nd p
ositi
ve io
ns a
re c
alle
d ca
tions
. Dis
cuss
the
form
atio
n of
ioni
c bo
nds
with
exa
mpl
es.
Dat
e:
Tim
e: 4
0 m
ins
Les
son
plan
69 1
Uni
t: 7
Topi
c: C
ompo
siti
onof
mat
ter
Teac
hing
obj
ecti
ves
Lea
rnin
g ou
tcom
es
Stud
ents
sho
uld
be a
ble
to:
Res
ourc
es/M
ater
ials
Act
ivit
ies/
CW
/HW
4.
Mol
ecul
es a
nd
com
poun
ds
•to
exp
lain
how
mol
ecul
es
and
com
poun
ds a
re
form
ed
•to
exp
lain
wha
t a
cova
lent
bon
d is
•to
exp
lain
the
law
of
cons
tant
com
posi
tion
•to
exp
lain
how
the
form
ulae
for
com
poun
ds
are
wor
ked
out
•ex
plai
n ho
w m
olec
ules
an
d co
mpo
unds
are
fo
rmed
•ex
plai
n th
e fo
rmat
ion
of
a co
vale
nt b
ond
•st
ate
the
law
of c
onst
ant
com
posi
tion
•de
scri
be th
e m
etho
d fo
r w
orki
ng o
ut th
e
form
ulae
of c
ompo
unds
Cha
rts
and
diag
ram
s of
ato
ms
and
mol
ecul
es, t
he
form
atio
n of
cov
alen
t bo
nds,
exa
mpl
es o
f th
e la
w o
f con
stan
t co
mpo
sitio
n, fo
rmul
ae
of c
ompo
unds
Rea
ding
: p 6
6, 6
7
Act
ivity
: 1, 5
CW
: Q2,
Q8
HW
: Q1
(c),
Q4
Key
wor
ds: m
olec
ule,
com
poun
d, c
oval
ent b
ond,
law
of c
onst
ant c
ompo
sitio
n, fo
rmul
a
Met
hod:
Ask
: Wha
t is
a co
mpo
und?
Dis
cuss
the
form
atio
n of
ioni
c an
d co
vale
nt c
ompo
unds
, with
dia
gram
s on
the
boar
d.
Exp
lain
the
role
of v
alen
cy in
the
join
ing
of a
tom
s in
diff
eren
t way
s. D
iscu
ss th
e ty
pes
of b
ond
that
form
com
poun
ds. E
xpla
in th
e m
etho
ds o
f wor
king
out
and
wri
ting
the
form
ulae
of c
ompo
unds
.
Dat
e:
Tim
e: 4
0 m
ins
Les
son
plan
701
Unit 7: Composition of matter Worksheet 1
Name: Date:
1. Write the valency of each of the following elements.
Element Valency
hydrogen
calcium
aluminium
carbon
sodium
oxygen
nitrogen
chlorine
magnesium
2. Use the valencies to write the chemical formulae of the following compounds:
Compound Valencies of elementsin the compound Formula
sodium chloride
carbon dioxide
aluminium chloride
nitrogen oxide
carbon monoxide
magnesium chloride
Photocopiable material
71 1
Unit 7: Composition of matter Worksheet 2
Name: Date:
Write the names of the elements represented by the following symbols:
Cu
Pt
K
Ag
Hg
Na
Au
Fe
Pb
Photocopiable material
721
Teaching objectives:• to explain the difference between physical and chemical changes• to explain physical and chemical changes taking place in the environment• to describe the characteristics of a chemical change• to explain the difference between exothermic and endothermic reactions• to explain the different types of chemical reactions• to explain how raw materials can be changed into useful products
Teaching strategy:Ask: Have you ever changed a material so that it had different characteristics? What did you do to it? How was it different? Explain that changes in materials are going on around us all the time. Most of the changes in materials are of two main kinds. In one kind of change the volume of the state of the material is changed. We call this a physical change. In the other kind, one material is changed into another material. We call this a chemical change. Explain that when a physical change takes place, a material is changed in size or form without actually becoming another material. If we stretch or squeeze a piece of soft rubber, we change its size, but it is still rubber. It springs back when we let it go. When sugar dissolves in water it changes form from a solid to a liquid, but it is still sugar. Ask: Can you describe some other physical changes? Discuss other physical changes such as the melting of ice. The freezing of water, drying of wet things, etc.
Ask: What happens when we burn a piece of paper? Can we get back the paper in its original form? Explain that when a chemical change takes place, a material is changed into one or more different materials. When we hold a piece of paper close to a lighted match the paper catches fire and burns. A flame is seen, some smoke and then nothing but ashes. Ask: Where has the paper disappeared to? Can we get the paper back? Explain that such a reaction cannot be reversed. We cannot get back the paper we have burnt. Similarly, other chemical changes occur when wood rots, iron rusts, milk sours, and cloth fades.
Ensure that the students understand the difference between a physical and chemical change. Discuss physical and chemical changes in everyday life. Explain that frying an egg is a one-way reaction. Once it has been fried it is impossible to change back into a raw egg. The burning of fuel is another one-way reaction. Many chemical reactions are of this type. Reactions which are one-way are called ‘irreversible reactions’. Ask: Are all reactions irreversible? Explain that there are some changes which can be reversed. A simple example is the physical change when ice is heated to form water. The water can be changed back into ice. Write the equation on the board. Explain that this change can be written as an equation. This is called a reversible reaction. The symbol for this is à ß.
Changes in matter
UNIT 8
73 1
Ask: How can chemical reaction help to produce useful products? Discuss the various chemical reactions used in industry to make fertilizers, plastics, margarine, soaps, and detergents, etc.Help the students to make soap in the laboratory.
Ask: What are fossil fuels? How are fossil fuels extracted from the ground? Discuss the formation of fossil fuels and the extraction of coal, oil, and natural gas. If possible take the students to an oil refinery and show them how crude oil is refined. Draw a fractionating column on the board and explain how the different fractions are separated.
Summarize the lesson.
Answers to Exercises in Unit 81. (a) When no new chemical substance is formed, a change is called a physical change. Physical
changes are easy to reverse.
When iron rusts, or a candle burns, new chemical compounds are made. It may be impossible to reverse the process. These types of changes are called chemical changes or chemical reactions.
(b) In a chemical reaction the following things happen:
• Anewsubstanceismade • Energyiseithergivenoutortakenin • Thechangeisalmostimpossibletoreverse
Although the atoms of each element combine in different ways, the same atoms that were present at the start are there at the end of the reaction. Because of this, the total mass of the substances remains the same.
(c) There are some reactions which can be reversed. A simple example is the physical change when ice is heated to form water. The water can be changed back into ice. Another reversible change is the heating of blue copper sulphate. It decomposes to give white copper sulphate powder and water vapour.
(d) A fertilizer is a combination of elements that a plant needs in order to grow strong and healthy. A good fertilizer contains the elements needed to promote healthy growth in plants. It must also be cheap to produce and soluble in water.
(e) In industry, ammonium nitrate is made by reacting ammonia with nitric acid.
(f) A plastic is a synthetic material which can easily be shaped. Plastics are usually tough and versatile. They are very good electrical insulators. They can be spun into fibres to make clothes and carpets, or moulded to make objects such as cups or chairs.
Plastics are polymers. Polymers contain very large molecules that are made by adding together many small molecules called monomers. Some familiar polymers are polyethene, polystyrene, and poly vinyl chloride (PVC). Nylon, Perspex, and Terylene are the common names of some other important plastics.
polyethene plastic bags
polystyrene ball-point pens
PVC hose pipes
Nylon rope, clothing
Amazing Science TG 7
741
Terylene clothing
(polyester) phenolic resins saucepan handles
Perspex rulers
Bakelite electrical fittings
(g) Crude oil is called a fossil fuel because it was made from fossils of animals that lived in the sea millions of years ago. Hundreds of millions of years ago, while ancient forests were starting to form coal on the land, other fossil fuels were being made under the sea. We use them now as oil and natural gas.
(h) petrol, kerosene
(i) solid fuels wood, coal liquid fuels petrol, kerosene gaseous fuels methane, butane
(j) Some of the fats and plant oils can be turned into valuable food such as margarine. The oil for making margarine comes from the seeds of plants such as sunflowers. The sunflower seeds are crushed and squeezed to extract oil. The oil is refined by heating with sodium hydroxide. The impurities in the oil react to form a sort of soap. The purified oil is separated and then washed. Hydrogenation of the unsaturated acids in the oil takes place when the oil is heated with hydrogen under pressure over a nickel catalyst (the catalyst speeds up the reaction which would otherwise be slow). The fat is then heated and steam is blown over it to take away the unpleasant smell. Colouring, flavouring, and salt may be added. Vitamins are also added to make it healthier to eat.
(k) Detergents are chemicals which, when dissolved in water, can remove dirt and grease from cloth, metal, ceramics, and of course, human skin. Soap is a detergent made from animal fats or plant oils.
(l) Crude oil was made from the microscopic plants and animals which lived in the sea. As they died, their bodies collected at the bottom of the ocean. Here they were covered by mud and sand. Over thousands of years the layers of mud and sand became very thick. High temperature and pressure changed them into thick black liquid called crude oil.
(m) gas, petrol, kerosene, diesel oil, lubricating oil, fuel oil, paraffin waxes, bitumen
2. chemical, physical, physical, chemical, chemical, physical, physical, physical, chemical, chemical
Additional Exercise
MCQs
(a) A change in which no new chemical substance is formed is called .
physical change chemical change ion exchange [physical change]
(b) A change can be easily reversed.
chemical physical ionic [physical]
(c) A change is a permanent change.
physical chemical reversible [chemical]
Unit 8 Changes in matter
75 1
Amazing Science TG 7
(d) A reaction can easily be changed back.
reversible irreversible chemical [reversible]
(e) Chemicals which are needed by plants for their proper growth are called .
nutrients food fertilizers [fertilizers]
(f) A synthetic material made from polymers is called. .
rubber wood plastic [plastic]
(g) Crude oil and natural gas are called .
fossil fuels natural fuels synthetic fuels [fossil fuels]
(h) Fossil fuels have been made from the that were on the Earth millions of years ago.
bodies of plants and animals rocks and soil water and mud
[bodies of plants and animals]
(i) are organic compounds made up of carbon, hydrogen, and oxygen.
Fats Plastics Glass [Fats]
(j) Electrical fittings are made of a plastic called .
melamine nylon bakelite [bakelite]
761
Uni
t: 8
Topi
c: C
hang
es
in m
atte
r
Teac
hing
obj
ecti
ves
Lea
rnin
g ou
tcom
es
Stud
ents
sho
uld
be a
ble
to:
Res
ourc
es/M
ater
ials
Act
ivit
ies/
CW
/HW
1.
Phy
sica
l and
ch
emic
al
chan
ge
•to
def
ine
phys
ical
cha
nge
•to
def
ine
chem
ical
ch
ange
•to
exp
lain
a r
ever
sibl
e re
actio
n
•de
fine
phys
ical
and
ch
emic
al c
hang
es a
nd
diffe
rent
iate
bet
wee
n th
e tw
o
•ex
plai
n ho
w r
ever
sibl
e re
actio
ns ta
ke p
lace
Ice
cube
s, ca
ndle
wax
, sal
t, w
ater
, iro
n fil
ings
, sul
phur
po
wde
r, ba
r mag
net,
rust
y na
il, m
atch
box
, cop
per
sulp
hate
, bur
ner,
chin
a di
sh
Rea
ding
: p 7
3, 7
4
CW
: Q2
HW
: Q1
(a)
(b)
(c)
Key
wor
ds: p
hysi
cal c
hang
e, m
eltin
g, d
isso
lvin
g, c
hem
ical
cha
nge,
che
mic
al r
eact
ion,
rev
ersi
ble
reac
tion
Met
hod:
Ask
: Wha
t hap
pens
whe
n yo
u bo
il an
egg
? Wha
t did
you
do
to it
? H
ow h
as it
cha
nged
? E
xpla
in th
at c
hang
es in
mat
eria
ls
are
taki
ng p
lace
aro
und
us a
ll th
e tim
e. M
ost o
f the
cha
nges
in m
ater
ials
are
of t
wo
mai
n ki
nds.
In o
ne k
ind
of c
hang
e th
e st
ate
and
the
volu
me
of a
mat
eria
l is
chan
ged.
We
call
this
kin
d of
cha
nge
a ph
ysic
al c
hang
e. T
here
is a
noth
er k
ind
of c
hang
e in
whi
ch a
m
ater
ial i
s ch
ange
d in
to a
com
plet
ely
diffe
rent
mat
eria
l. T
his
kind
of c
hang
e is
cal
led
a ch
emic
al c
hang
e.E
xpla
in th
at w
hen
a ph
ysic
al c
hang
e ta
kes
plac
e, a
mat
eria
l is
chan
ged
in s
ize
or fo
rm w
ithou
t act
ually
bec
omin
g an
othe
r m
ater
ial.
If w
e st
retc
h or
squ
eeze
a p
iece
of s
oft r
ubbe
r, w
e ch
ange
its
size
, but
it is
stil
l rub
ber.
It s
prin
gs b
ack
whe
n w
e le
t it g
o.
Whe
n su
gar
diss
olve
s in
wat
er it
cha
nges
form
from
a s
olid
to a
liqu
id, b
ut it
is s
till s
ugar
.A
sk th
e st
uden
ts to
des
crib
e ot
her
phys
ical
cha
nges
from
thei
r ev
eryd
ay o
bser
vatio
n, s
uch
as th
e m
eltin
g of
ice,
free
zing
of w
ater
, dr
ying
of w
et c
loth
es, e
tc. A
sk: W
hat h
appe
ns w
hen
we
burn
a p
iece
of p
aper
? C
an w
e ge
t the
pap
er b
ack
in it
s or
igin
al fo
rm?
Exp
lain
that
whe
n a
chem
ical
cha
nge
take
s pl
ace,
a m
ater
ial i
s ch
ange
d in
to o
ne o
r m
ore
diffe
rent
mat
eria
ls. F
or e
xam
ple,
whe
n w
e ho
ld a
pie
ce o
f pap
er c
lose
to a
ligh
ted
mat
ch th
e pa
per
catc
hes
fire
and
burn
s. A
flam
e is
see
n, s
ome
smok
e, a
nd th
en n
othi
ng
but a
shes
. Ask
: Whe
re h
as th
e pa
per
disa
ppea
red
to?
Can
we
get t
he p
aper
bac
k? E
xpla
in th
at s
uch
a re
actio
n ca
nnot
be
reve
rsed
. W
e ca
nnot
get
bac
k th
e pa
per
we
have
bur
nt. S
imila
rly,
oth
er c
hem
ical
cha
nges
occ
ur w
hen
woo
d ro
ts, i
ron
rust
s, m
ilk tu
rns
sour
, an
d th
e co
lour
of c
loth
fade
s. E
nsur
e th
at th
e st
uden
ts u
nder
stan
d th
e di
ffere
nce
betw
een
phys
ical
and
che
mic
al c
hang
es. D
iscu
ss
phys
ical
and
che
mic
al c
hang
es in
eve
ryda
y lif
e.A
sk: W
hat t
ype
of a
rea
ctio
n is
the
fryi
ng o
f an
egg?
Exp
lain
that
it is
a o
ne-w
ay r
eact
ion.
Onc
e it
has
been
frie
d it
is im
poss
ible
to
cha
nge
it ba
ck in
to a
raw
egg
. The
bur
ning
of f
uel i
s an
othe
r on
e-w
ay r
eact
ion.
Alm
ost a
ll ch
emic
al r
eact
ions
are
of t
his
type
. R
eact
ions
whi
ch a
re o
f thi
s ty
pe a
re c
alle
d ir
reve
rsib
le r
eact
ions
. A
sk: A
re a
ll re
actio
ns ir
reve
rsib
le?
Exp
lain
that
ther
e ar
e so
me
chan
ges
that
can
be
reve
rsed
. A s
impl
e ex
ampl
e is
that
of t
he ic
e ch
angi
ng to
wat
er. T
he w
ater
can
be
chan
ged
back
into
ice.
W
rite
the
chan
ge o
n th
e bo
ard:
ice
wat
er, w
ater
ic
e.
Exp
lain
that
this
cha
nge
can
also
be
wri
tten
with
arr
ows
in th
e op
posi
te d
irec
tion.
ice
wat
er.
Thi
s ty
pe o
f rea
ctio
n is
cal
led
a re
vers
ible
rea
ctio
n.
Dat
e:
Tim
e: 4
0 m
ins
Les
son
plan
77 1
Uni
t: 8
Topi
c: C
hang
es
in m
atte
r
Teac
hing
obj
ecti
ves
Lea
rnin
g ou
tcom
es
Stud
ents
sho
uld
be a
ble
to:
Res
ourc
es/M
ater
ials
Act
ivit
ies/
CW
/HW
1.
Phy
sica
l and
ch
emic
al
chan
ge
•to
def
ine
phys
ical
cha
nge
•to
def
ine
chem
ical
ch
ange
•to
exp
lain
a r
ever
sibl
e re
actio
n
•de
fine
phys
ical
and
ch
emic
al c
hang
es a
nd
diffe
rent
iate
bet
wee
n th
e tw
o
•ex
plai
n ho
w r
ever
sibl
e re
actio
ns ta
ke p
lace
Ice
cube
s, ca
ndle
wax
, sal
t, w
ater
, iro
n fil
ings
, sul
phur
po
wde
r, ba
r mag
net,
rust
y na
il, m
atch
box
, cop
per
sulp
hate
, bur
ner,
chin
a di
sh
Rea
ding
: p 7
3, 7
4
CW
: Q2
HW
: Q1
(a)
(b)
(c)
Key
wor
ds: p
hysi
cal c
hang
e, m
eltin
g, d
isso
lvin
g, c
hem
ical
cha
nge,
che
mic
al r
eact
ion,
rev
ersi
ble
reac
tion
Met
hod:
Ask
: Wha
t hap
pens
whe
n yo
u bo
il an
egg
? Wha
t did
you
do
to it
? H
ow h
as it
cha
nged
? E
xpla
in th
at c
hang
es in
mat
eria
ls
are
taki
ng p
lace
aro
und
us a
ll th
e tim
e. M
ost o
f the
cha
nges
in m
ater
ials
are
of t
wo
mai
n ki
nds.
In o
ne k
ind
of c
hang
e th
e st
ate
and
the
volu
me
of a
mat
eria
l is
chan
ged.
We
call
this
kin
d of
cha
nge
a ph
ysic
al c
hang
e. T
here
is a
noth
er k
ind
of c
hang
e in
whi
ch a
m
ater
ial i
s ch
ange
d in
to a
com
plet
ely
diffe
rent
mat
eria
l. T
his
kind
of c
hang
e is
cal
led
a ch
emic
al c
hang
e.E
xpla
in th
at w
hen
a ph
ysic
al c
hang
e ta
kes
plac
e, a
mat
eria
l is
chan
ged
in s
ize
or fo
rm w
ithou
t act
ually
bec
omin
g an
othe
r m
ater
ial.
If w
e st
retc
h or
squ
eeze
a p
iece
of s
oft r
ubbe
r, w
e ch
ange
its
size
, but
it is
stil
l rub
ber.
It s
prin
gs b
ack
whe
n w
e le
t it g
o.
Whe
n su
gar
diss
olve
s in
wat
er it
cha
nges
form
from
a s
olid
to a
liqu
id, b
ut it
is s
till s
ugar
.A
sk th
e st
uden
ts to
des
crib
e ot
her
phys
ical
cha
nges
from
thei
r ev
eryd
ay o
bser
vatio
n, s
uch
as th
e m
eltin
g of
ice,
free
zing
of w
ater
, dr
ying
of w
et c
loth
es, e
tc. A
sk: W
hat h
appe
ns w
hen
we
burn
a p
iece
of p
aper
? C
an w
e ge
t the
pap
er b
ack
in it
s or
igin
al fo
rm?
Exp
lain
that
whe
n a
chem
ical
cha
nge
take
s pl
ace,
a m
ater
ial i
s ch
ange
d in
to o
ne o
r m
ore
diffe
rent
mat
eria
ls. F
or e
xam
ple,
whe
n w
e ho
ld a
pie
ce o
f pap
er c
lose
to a
ligh
ted
mat
ch th
e pa
per
catc
hes
fire
and
burn
s. A
flam
e is
see
n, s
ome
smok
e, a
nd th
en n
othi
ng
but a
shes
. Ask
: Whe
re h
as th
e pa
per
disa
ppea
red
to?
Can
we
get t
he p
aper
bac
k? E
xpla
in th
at s
uch
a re
actio
n ca
nnot
be
reve
rsed
. W
e ca
nnot
get
bac
k th
e pa
per
we
have
bur
nt. S
imila
rly,
oth
er c
hem
ical
cha
nges
occ
ur w
hen
woo
d ro
ts, i
ron
rust
s, m
ilk tu
rns
sour
, an
d th
e co
lour
of c
loth
fade
s. E
nsur
e th
at th
e st
uden
ts u
nder
stan
d th
e di
ffere
nce
betw
een
phys
ical
and
che
mic
al c
hang
es. D
iscu
ss
phys
ical
and
che
mic
al c
hang
es in
eve
ryda
y lif
e.A
sk: W
hat t
ype
of a
rea
ctio
n is
the
fryi
ng o
f an
egg?
Exp
lain
that
it is
a o
ne-w
ay r
eact
ion.
Onc
e it
has
been
frie
d it
is im
poss
ible
to
cha
nge
it ba
ck in
to a
raw
egg
. The
bur
ning
of f
uel i
s an
othe
r on
e-w
ay r
eact
ion.
Alm
ost a
ll ch
emic
al r
eact
ions
are
of t
his
type
. R
eact
ions
whi
ch a
re o
f thi
s ty
pe a
re c
alle
d ir
reve
rsib
le r
eact
ions
. A
sk: A
re a
ll re
actio
ns ir
reve
rsib
le?
Exp
lain
that
ther
e ar
e so
me
chan
ges
that
can
be
reve
rsed
. A s
impl
e ex
ampl
e is
that
of t
he ic
e ch
angi
ng to
wat
er. T
he w
ater
can
be
chan
ged
back
into
ice.
W
rite
the
chan
ge o
n th
e bo
ard:
ice
wat
er, w
ater
ic
e.
Exp
lain
that
this
cha
nge
can
also
be
wri
tten
with
arr
ows
in th
e op
posi
te d
irec
tion.
ice
wat
er.
Thi
s ty
pe o
f rea
ctio
n is
cal
led
a re
vers
ible
rea
ctio
n.
Uni
t: 8
Topi
c: C
hang
es
in m
atte
r
Teac
hing
obj
ecti
ves
Lea
rnin
g ou
tcom
es
Stud
ents
sho
uld
be a
ble
to:
Res
ourc
es/M
ater
ials
Act
ivit
ies/
CW
/HW
2.
Cha
ngin
g ra
w m
ater
ials
in
to u
sefu
l pr
oduc
ts
Fe
rtili
zers
•to
exp
lain
how
raw
m
ater
ials
can
be
chan
ged
into
use
ful
prod
ucts
•to
des
crib
e fe
rtili
zers
•to
dis
cuss
the
uses
of
fert
ilize
rs
•ex
plai
n ho
w r
aw m
ater
ials
ca
n be
cha
nged
into
use
ful
prod
ucts
•ex
plai
n ho
w fe
rtili
zers
wor
k
•de
scri
be th
e ha
rmfu
l effe
cts
of th
e im
prop
er u
se o
f fe
rtili
zers
Pic
ture
s of
a fe
rtili
zer
fact
ory,
bag
s of
di
ffere
nt ty
pes
of
fert
ilize
rs
Rea
ding
: p 7
4, 7
5
Act
ivity
: 3
CW
: Q1
(d)
HW
: Q1
(e)
Key
wor
ds: f
ertil
izer
, nitr
ogen
, pho
spho
rus,
pot
assi
um, a
mm
oniu
m n
itrat
e
Met
hod:
Ask
: Wha
t do
plan
ts n
eed
to g
row
str
ong
and
heal
thy?
Dis
cuss
pla
nt n
eeds
. Ask
: Fro
m w
here
do
plan
ts g
et m
iner
al
salts
? Why
do
plan
ts n
eed
min
eral
s? D
iscu
ss th
e im
port
ance
of m
iner
als
for
plan
ts. D
iscu
ss th
e ni
trog
en c
ycle
and
how
pla
nts
use
the
nitr
ates
in th
e so
il. E
xpla
in th
e us
es o
f org
anic
and
che
mic
al fe
rtili
zers
for
plan
ts, e
spec
ially
cro
ps. A
sk: H
ow a
re c
hem
ical
fe
rtili
zers
mad
e? E
xpla
in th
e m
anuf
actu
re o
f fer
tiliz
ers
in fa
ctor
ies
with
pic
ture
s an
d ch
arts
.
Wri
te th
e na
mes
of t
he d
iffer
ent c
hem
ical
s th
at a
re u
sed
to p
rodu
ce fe
rtili
zers
. Dis
cuss
the
impo
rtan
ce o
f fer
tiliz
ers.
Als
o di
scus
s th
e ha
rmfu
l effe
cts
of u
sing
too
muc
h fe
rtili
zer.
Dat
e:
Tim
e: 4
0 m
ins
Les
son
plan
781
Uni
t: 8
Topi
c: C
hang
es
in m
atte
r
Teac
hing
obj
ecti
ves
Lea
rnin
g ou
tcom
es
Stud
ents
sho
uld
be a
ble
to:
Res
ourc
es/M
ater
ials
Act
ivit
ies/
CW
/HW
3.
Pla
stic
s •
to d
efin
e pl
astic
s
•to
exp
lain
how
pla
stic
s ar
e m
anuf
actu
red
•to
dis
cuss
the
uses
of
plas
tics
•de
fine
plas
tics
•ex
plai
n ho
w p
last
ics
are
mad
e
•de
scri
be h
ow w
e us
e pl
astic
s
Pla
stic
item
s or
pi
ctur
es o
f thi
ngs
mad
e of
pla
stic
Rea
ding
: p 7
5, 7
6
Act
ivity
: 4
Pro
ject
: 1
CW
: Q1
(f)
Key
wor
ds: p
last
ic, s
ynth
etic
, pol
ymer
, pol
yeth
ene,
mon
omer
Met
hod:
Sho
w th
e st
uden
ts o
bjec
ts m
ade
of p
last
ic. A
sk: W
hat i
s pl
astic
? D
iscu
ss th
e pr
oper
ties
of p
last
ic.
Exp
lain
that
pla
stic
s ar
e m
ade
up o
f man
y sm
all m
olec
ules
cal
led
mon
omer
s. L
ots
of m
onom
ers
join
toge
ther
to m
ake
the
poly
mer
s of
whi
ch p
last
ics
are
mad
e. W
rite
the
nam
es o
f som
e fa
mili
ar p
olym
ers
such
as
poly
ethe
ne, p
olys
tyre
ne, a
nd P
VC
. D
iscu
ss th
e us
es o
f diff
eren
t kin
ds o
f pla
stic
to m
ake
ever
yday
item
s.
Dat
e:
Tim
e: 4
0 m
ins
Les
son
plan
79 1
Uni
t: 8
Topi
c: C
hang
es
in m
atte
r
Teac
hing
obj
ecti
ves
Lea
rnin
g ou
tcom
es
Stud
ents
sho
uld
be a
ble
to:
Res
ourc
es/M
ater
ials
Act
ivit
ies/
CW
/HW
4.
Foss
il fu
els
R
efin
ing
crud
e oi
l
•to
des
crib
e fo
ssil
fuel
s
•to
exp
lain
how
cru
de o
il is
ref
ined
to m
ake
usef
ul
prod
ucts
•ex
plai
n ho
w fo
ssil
fuel
s w
ere
mad
e
•ex
plai
n th
e re
finin
g pr
oces
s of
cru
de o
il to
m
ake
usef
ul p
rodu
cts
Pic
ture
s of
foss
ils,
coal
, pet
role
um,
natu
ral g
as p
lant
, fr
actio
natin
g co
lum
n
Rea
ding
: p 7
6, 7
7
Pro
ject
: 2
CW
: Q
1 (g
) (h
)
HW
: Q
1 (i
) (l
) (m
)
Key
wor
ds: f
ossi
l fue
l, cr
ude
oil,
frac
tiona
l dis
tilla
tion,
ref
inin
g cr
ude
oil,
hydr
ocar
bon,
frac
tiona
l dis
tilla
tion,
frac
tiona
ting
tow
er,
frac
tion
Met
hod:
Sho
w th
e st
uden
ts p
ictu
res
of fo
ssils
. Ask
: Wha
t are
foss
ils?
How
are
foss
ils m
ade?
Wha
t inf
orm
atio
n do
we
get f
rom
fo
ssils
?
Dis
cuss
the
form
atio
n of
foss
il fu
els
in th
e se
a an
d on
land
. Exp
lain
that
mill
ions
of y
ears
ago
coa
l was
form
ed fr
om p
lant
s, a
nd o
il w
as m
ade
from
the
bodi
es o
f mic
rosc
opic
pla
nts
and
anim
als
that
live
d in
the
sea.
Show
the
stud
ents
cha
rts
and
diag
ram
s of
the
frac
tiona
l dis
tilla
tion
of c
rude
oil
and
expl
ain
the
use
of th
e di
ffere
nt g
roup
s of
co
mpo
unds
cal
led
frac
tions
.
Dat
e:
Tim
e: 4
0 m
ins
Les
son
plan
801
Uni
t: 8
Topi
c: C
hang
esin
mat
ter
Teac
hing
obj
ecti
ves
Lea
rnin
g ou
tcom
es
Stud
ents
sho
uld
be a
ble
to:
Res
ourc
es/M
ater
ials
Act
ivit
ies/
CW
/HW
5.
Fat
s
M
akin
g m
arga
rine
and
so
ap fr
om fa
ts
•to
def
ine
fats
•to
exp
lain
the
impo
rtan
ce o
f fat
s fo
r al
l liv
ing
thin
gs
•ex
plai
n th
e co
mpo
sitio
n of
fats
•id
entif
y th
e us
es o
f fat
s
•ex
plai
n ho
w fa
ts c
an
be u
sed
to m
ake
usef
ul
prod
ucts
Pic
ture
s an
d ch
arts
of
the
uses
of f
ats,
m
akin
g m
arga
rine
, de
terg
ents
, and
soa
ps
Rea
ding
: p 7
7, 7
8, 7
9
Act
ivity
: 1, 2
CW
: Q1
(j)
HW
: Q1
(k)
Key
wor
ds: f
at, l
ipid
, fat
ty a
cid,
mar
gari
ne, h
ydro
gena
tion
dete
rgen
t, so
ap
Met
hod:
Ask
: Wha
t are
fats
? Wha
t are
fats
mad
e of
? E
xpla
in th
at fa
ts a
re m
ade
from
fatt
y ac
ids.
Oils
are
liqu
id a
nd fa
ts a
re s
olid
.
Ask
: How
are
fats
use
d in
the
body
? D
iscu
ss th
e im
port
ance
of f
ats.
Dis
cuss
the
proc
ess
by w
hich
mar
gari
ne is
mad
e, w
ith th
e he
lp o
f cha
rts
and
diag
ram
s.
Ask
: Wha
t is
soap
? Wha
t is
the
diffe
renc
e be
twee
n a
soap
and
a d
eter
gent
? E
xpla
in th
e di
ffere
nce
betw
een
soap
and
det
erge
nt.
Exp
lain
the
proc
ess
by w
hich
soa
p is
mad
e in
dust
rial
ly.
Dat
e:
Tim
e: 4
0 m
ins
Les
son
plan
81 1
Unit 8: Changes in matter Worksheet 1
Name: Date:
1. Label the diagram of the fractional distillation of crude oil:
2. Complete the table below.
Name of the fraction Use
bitumen
paraffin wax
fuel oil
lubricating oil
diesel oil
kerosene
petrol
gas
Photocopiable material
821
Unit 8: Changes in matter Worksheet 2
Name: Date:
1. Write the stages in the production of margarine in the correct order:
a. Vitamins are added to make it healthier to eat.
b. Sunflower seeds are crushed and squeezed to extract oil.
c. The impurities in oil react to form a sort of soap.
d. The purified oil is separated and then washed.
e. The oil is refined by heating with sodium hydroxide.
f. Colour, flavouring, and salt may be added.
g. The fat is heated and steam blown over it to take away the unpleasant smell.
h. Oil is heated under pressure over a nickel catalyst, with hydrogen, for the hydrogenation of the unsaturated acids in the oil, to make fats.
2. Explain the difference between a soap and a detergent.
3. What are the harmful effects of using too much chemical fertilizer?
Photocopiable material
83 1
Test paper 2Time: 3 hours Total marks: 100
1. Attempt any five questions. (All questions carry equal marks.] [50]
(a) What is hard water? What causes the hardness of water? How can hard water be made soft?
(b) Describe the structure of an atom. What is the atomic number and mass number of an atom?
(c) (i) What is an element? (ii) Write the symbols of the following elements: carbon, nitrogen, hydrogen, oxygen, sulphur, iodine, phosphorus, calcium, chlorine, zinc.
(d) What is a compound? Write the formulae for the following compounds:
sodium chloride, sodium hydroxide, potassium hydroxide, carbon dioxide, water, sugar, glucose, copper oxide, copper sulphate, ammonia.
(e) Explain the difference between the following:
(i) proton and electron (ii) symbol and formula (iii) atom and molecule (iv) ionic bond and covalent bond (v) element and compound
(f) Explain the difference between a physical and a chemical change.
How do we know that a chemical change has taken place?
(g) What is a fertilizer? What are some of the harmful effects of the improper use of fertilizer?
(h) What are plastics? Write the names of the plastic that is used for making:
plastic bags, ballpoint pens, hose pipes, rope, clothing, saucepan handles, rulers, electrical fittings.
2. Draw a diagram to show what happens when a sodium atom reacts with a chlorine atom. [5]
3. Draw diagrams to show the bonding in a molecule of water, ammonia, methane. [5]
4. How can soap be made in the laboratory? [10]
5. Draw a fractionating column and write the names of the different fractions being separated in it.
[10]
6. Fill in the blanks to describe how margarine is made.
Some of the fats and plant oils can be turned into valuable food such as . The oil for making margarine comes from the of plants such as sunflowers.
Test paper 2
841
The sunflower seeds are and squeezed to extract oil. The oil is refined by heating with . The in the oil react to form a sort of soap. The purified oil is separated and then . of the unsaturated acids in the oil takes place when the oil is heated with hydrogen under pressure over a nickel catalyst (the catalyst speeds up the reaction which would otherwise be slow). The fat is then heated and is blown over it to take away the unpleasant smell. Colouring,
, and salt may be added. are also added to make it healthier to eat.
[10]
7. Label this diagram of a filtration plant. [10]
Test paper 2
85 1
Teaching objectives:• to explain heat energy transfers from one body to another• to explain the methods of heat transfer by conduction, convection, and radiation• to explain by giving everyday examples of convection currents in nature• to describe the use of conductors in everyday life• to explain what a vacuum flask is and describe how it helps to maintain the temperature
Teaching strategy:Place some ice cubes in a glass dish and press them with your finger. Ask: Why does the ice melt? Explain the movement of molecules as they gain energy from the hand. Ask: Why does water in a pan begin to boil when placed on a stove? Explain the gain of energy by the molecules from the fire. Dip a teaspoon in a cup of hot tea. Ask: Why does the metallic handle get hot? Why do we feel warm when we sit in front of a room heater? Explain heat as a form of energy that travels from one place to another in waves and radiations. Perform simple experiments shown in the textbook to explain the methods of heat transfer.
Ask: Why do we cover a teapot with a tea cosy? How does a blanket keep us warm? Explain the use of insulators in daily life. Ask: Why do you feel hot after exercise? Why do you feel cool under a fan? Explain heat loss by convection. Ask: What is the normal temperature of the human body? How is the normal body temperature maintained at a constant level? Explain the process of sweating and cooling. Ask: How do we measure the temperature of our bodies? Explain the use of thermometers. Show a clinical and a laboratory thermometer to the students and explain their working. Draw the temperature scales on the board and show them the lower and upper marks. Explain the difference between the scales and explain the absolute zero and its use in scientific experiments. Explain the uses of the various thermometers. Explain the interconversion of the temperature scales with the help of formulae.
Summarize the lesson.
Answers to Activities7. (a) Heat will flow from a hotter body to a cooler one.
(b) The particles will begin to vibrate faster on gaining heat energy.
(c) Heat flow will be greatest between A and D, because there is a great temperature difference.
(d) Heat flow will be the least between A and B , because the particles of cold objects have least energy.
UNIT 9Heat and energy
861
8. Alcohol thermometer
Electrical thermometer
Electrical thermometer
Alcohol thermometer
Mercury thermometer
Answers to Exercises in Unit 91. (a) Heat is a type of energy found in an object that has a higher temperature than its surroundings.
(b) When an object is heated, its molecules gain energy and start moving faster. As they vibrate, they bump into each other at a faster rate and push the particles in front of them. As this movement continues, heat travels from one end of the object to the other.
(c) Materials, like rubber, wood, and plastic that do not allow heat to travel through them are called bad conductors of heat. Materials, like wool, fur, and feathers that do not conduct heat or electricity easily are called insulators.
Insulators are substances that are poor conductors of heat and electricity. The handles of pots and pans are made of wood or plastic, so that heat is not conducted from the pan to the handle and we do not burn our hands. Firefighters wear clothes made of an insulating material called fiberglass. Air is a good insulator. We wear woollen clothes in winter to keep warm because wool traps air between its fibres.
(d) Heat can travel through solids by conduction. If one end of a metal spoon is dipped in hot water, the other end heats up after a short while. This happens because the molecules at the dipped end gain energy from the hot water, start vibrating, and push the molecules in front of them. On gaining energy, these molecules also start vibrating, and in this way a chain reaction is set up by which the other end of the spoon heats up.
Convection occurs when heat is transferred from one part of a fluid to another by the movement of the fluid itself. The ventilation of a room and heating water in a pan are examples of convection.
Radiation is a particular way in which energy travels. This energy need not be carried by a medium such as a solid, liquid, or gas. It can travel in space because it is not carried by moving particles which need a medium to travel in. Earth is heated by the heat radiation of the Sun. This heat travels through space and reaches the Earth.
(e) Conductivity is the ability of a material to conduct heat. To compare the conductivity of different materials take some rods which are of the same length and thickness but are made of different materials, such as wood, iron, copper, aluminium, etc. Dip them in wax and allow them to cool, then pass them through a specially made metallic box which has holes in its sides. Pour hot water in the box. After a few minutes, remove the rods. You will observe that the wax melts to a different distance on each rod.
(f) To prove that water is a bad conductor of heat wrap a cube of ice in a piece of gauze and drop it into a test tube full of water. Hold the top of the tube close to a Bunsen flame. You will observe that although the water at the top boils, the ice at the bottom of the tube does not melt.
(g) To demonstrate convection in liquids fill a conical flask with tap water and drop a large crystal of potassium permanganate into it. Heat the flask. An upward current of coloured water will
Unit 9 Heat and energy
87 1
Amazing Science TG 7
rise and spread outwards. It will then move down the sides of the flask, showing that a convection current has been set up.
(h) During the daytime, the land heats up quickly by the heat of the Sun. As a result, the air above it becomes hot. As this air expands and rises, the cooler air above the sea blows in to take its place. This is called a sea breeze.
At night, the sea water, which has absorbed heat during the day, remains hot for a longer time than the land, and so the air above the sea warms up. It expands and rises and in this way the convection current is reversed. The breeze now blows from the cooler land to the sea and is called a land breeze.
(i) Radiation is a particular way in which energy travels. This energy need not be carried by a medium such as a solid, liquid, or gas. It can travel in space because it is not carried by moving particles which need a medium to travel in. The Earth is heated by the heat radiation of the Sun. This heat travels through space and reaches the Earth.
(j) A thermos flask consists of a double-walled glass bottle which has a vacuum between the two walls. The inner sides of the walls are shiny. The mouth of the bottle is closed with a cork or plastic stopper. The glass bottle is fitted into a metallic or plastic container. Heat cannot enter or leave the flask due to the vacuum which checks conduction and convection. The shiny surface reflects the heat waves. Anything inside the flask will remain hot or cold for a long time.
(k) The degree of hotness or coldness of a body is called its temperature. Temperature depends on the internal kinetic energy of the molecules of a substance. When a body is cold, its molecules move slowly. When it is heated, its molecules begin to move faster. As these molecules move, they begin to vibrate and bump into each other. In doing so, they push each other apart and that is how the change of state in a substance occurs (from solid to liquid and liquid to gas). This also explains the expansion of solids, liquids, and gases on heating.
(l) We cannot rely on our sense of touch to measure the temperature of a body. If you keep your hands in cold water and then dip them in warm water, the water will feel very hot. If you keep your hands in hot water, and then dip them in warm water, the water will feel cold. In order to find out the exact temperature of a body an instrument called a thermometer is used.
(m) A mercury thermometer contains mercury, which expands and contracts with the rise and fall of temperature. The clinical thermometer is a mercury thermometer, and is used to measure the temperature of the human body. It cannot be used to measure temperatures below –39°C because mercury solidifies at temperatures below this.
An alcohol thermometer contains alcohol. It is cheap and easy to use. It can measure very low temperatures because alcohol does not solidify even at –115°C. It is used in the laboratory, in refrigerators, and in deep-freezes.
A maximum and minimum thermometer is used to record the maximum and minimum temperatures of a place every 24 hours. It consists of two bulbs, A and B. Bulb A is partly filled with alcohol and has a vacuum at the top, while bulb B is completely filled with mercury. A U- shaped tube filled with mercury is attached to the bulbs. Indices x and y are attached with springs to the top of the mercury column. Temperature scales are marked on both arms of the U- shaped tube. The expansion and contraction of the alcohol due to the rise and fall in temperature indicate the maximum temperature on the scale towards the A-bulb side and the minimum temperature on the scale on the B-bulb side.
881
Digital thermometers are electronic thermometers. They are compact and inexpensive and are used for measuring and displaying temperature in numeric values with great precision.
The temperature deep inside a furnace or a kiln needs constant checking. Mercury or alcohol thermometers are not suitable because they ca not measure very high temperatures. Besides you cannot get close enough to the scale to read it. Electrical thermometers are easy to read because they have a digital display. The scale is placed well away from the temperature detector. Temperature readings can be read by a computer, and the temperature range is from -200 to 1600 degrees centigrade or more.
2. (a) When an object is heated its molecules gain energy.
(b) Rubber and wood are bad conductors of electricity.
(c) The ability to conduct heat is called conductivity.
(d) Water is a bad conductor of heat.
(e) The flow of heat through a liquid is called convection.
(f) Monsoon winds are convection current winds.
(g) During the daytime, land gets heated up more quickly than water.
(h) Radiation does not need a medium to travel in.
(i) When a substance is hot its molecules move more quickly.
(j) Absolute zero is equal to 273 K.
3. a) 0+273 b) 100 +273 c) 180 + 273 d) -173 + 273 e) -100 + 273
4. a) 0 - 273 b) 73 -273 c) 150 - 273 d) 473 - 273 e) 561 - 273
Additional Exercise
MCQs
(a) The transfer of heat energy by the vibration of particles is called .
conduction convection radiation [conduction]
(b) The particles in the hotter region move to the colder region when heat energy travels by .
conduction convection radiation [convection]
(c) are better conductors than fluids.
Solids Liquids Gases [Solids]
(d) Which one of the following is the best conductor of heat?
Copper Glass Air [Copper]
(e) Heat travels from one end of an iron rod to the other end by .
conduction convection radiation [conduction]
Unit 9 Heat and energy
89 1
Amazing Science TG 7
(f) Water is a conductor of heat.
good conductor bad conductor bad insulator [bad conductor]
(g) Liquids and gases are of heat.
good conductors poor conductors bad insulators [poor conductors]
(h) Hot air moves .
downwards upwards forwards [upwards]
(i) Which one of the following statements is wrong?
Convection can take place in a liquid. Convection can take place in a vacuum.
A convection current can be present in gas. [Convection can take place in a vacuum.]
(j) The sun heats up the Earth by .
conduction convection radiation [radiation]
901
Uni
t: 9
Topi
c: H
eat a
nd
ener
gy
Teac
hing
obj
ecti
ves
Lea
rnin
g ou
tcom
es
Stud
ents
sho
uld
be a
ble
to:
Res
ourc
es/M
ater
ials
Act
ivit
ies/
CW
/HW
1.
Con
duct
ors
and
insu
lato
rs•
to d
efin
e he
at
•to
com
pare
co
nduc
tors
and
in
sula
tors
•de
scri
be h
eat a
s a
form
of
ene
rgy
•di
ffere
ntia
te b
etw
een
cond
ucto
r an
d in
sula
tors
Sam
ples
of i
nsul
ator
s an
d co
nduc
tors
R
eadi
ng: p
84
CW
: Q1
(a)
HW
: Q1
(b)
(c)
Key
wor
ds: v
ibra
te, t
empe
ratu
re, i
nter
nal e
nerg
y, g
ood
cond
ucto
r, ba
d co
nduc
tor,
insu
lato
r
Met
hod:
Dis
cuss
the
com
posi
tion
of m
atte
r. E
xpla
in th
at p
artic
les
of m
atte
r ar
e al
way
s m
ovin
g. W
hen
an o
bjec
t is
heat
ed, i
t ab
sorb
s he
at e
nerg
y. I
ts p
artic
les
gain
ene
rgy
and
they
sta
rt m
ovin
g fa
ster
. Whe
n th
is h
appe
ns th
e te
mpe
ratu
re r
ises
. The
par
ticle
s ha
ve m
ore
inte
rnal
ene
rgy.
Exp
lain
that
hea
t is
a de
gree
of t
empe
ratu
re. S
cien
tific
ally
spe
akin
g, h
eat i
s a
kind
of e
nerg
y fo
und
in
an o
bjec
t tha
t has
a h
ighe
r te
mpe
ratu
re th
an it
s su
rrou
ndin
gs.
Ask
: How
doe
s he
at tr
avel
from
one
end
of a
n ob
ject
to th
e ot
her?
Exp
lain
that
whe
n an
obj
ect i
s he
ated
its
part
icle
s ga
in e
nerg
y an
d th
ey b
egin
to m
ove
fast
er. A
s th
ey v
ibra
te th
ey b
ump
into
eac
h ot
her
at a
fast
er r
ate
and
they
pus
h th
e pa
rtic
les
in fr
ont o
f th
em. A
s th
is m
ovem
ent c
ontin
ues,
hea
t tra
vels
from
one
end
of t
he o
bjec
t to
the
othe
r. D
efin
e co
nduc
tors
as
mat
eria
ls th
at a
llow
he
at to
trav
el th
roug
h th
em, a
nd in
sula
tors
as
mat
eria
ls th
at d
o no
t.
Dat
e:
Tim
e: 4
0 m
ins
Les
son
plan
91 1
Uni
t: 9
Topi
c: H
eat
and
ener
gy
Teac
hing
obj
ecti
ves
Lea
rnin
g ou
tcom
es
Stud
ents
sho
uld
be a
ble
to:
Res
ourc
es/M
ater
ials
Act
ivit
ies/
CW
/HW
2.
Met
hods
of
heat
tran
sfer
: co
nduc
tion
•to
des
crib
e he
at tr
ansf
er
in m
ater
ials
•to
exp
lain
con
duct
ion
of h
eat
•ex
plai
n th
at h
eat i
s tr
ansf
erre
d in
mat
eria
ls
•ex
plai
n ho
w th
e
cond
uctio
n of
hea
t tak
es
plac
e in
sol
ids
Cop
per
wir
e, b
eake
r, ho
t wat
er, m
etal
spo
on,
rods
of w
ood,
iron
, co
pper
, alu
min
ium
, m
etal
lic b
ox w
ith h
oles
, m
olte
n w
ax, t
est t
ube,
bu
rner
, ice
, gau
ze
Rea
ding
: p 8
4, 8
5
Act
ivity
: 4, 7
CW
: Q1
(d)
HW
: Q1
(e)
(f)
Key
wor
ds: c
ondu
ctio
n, c
ondu
ctiv
ity
Met
hod:
Ask
: Wha
t hap
pens
to a
met
al te
aspo
on if
it is
pla
ced
in a
cup
of h
ot w
ater
? D
iscu
ss c
ondu
ctio
n of
hea
t thr
ough
sol
ids.
Exp
lain
that
the
mol
ecul
es a
t the
dip
ped
end
gain
ene
rgy
from
the
hot w
ater
, sta
rt v
ibra
ting,
and
pus
h th
e m
olec
ules
in fr
ont o
f th
em. I
n th
is w
ay a
cha
in r
eact
ion
is s
et u
p an
d th
e ot
her
end
of th
e sp
oon
beco
mes
hot
.
Perf
orm
the
expe
rim
ents
on
page
s 84
and
85
to d
emon
stra
te th
e co
nduc
tion
of h
eat.
Dat
e:
Tim
e: 4
0 m
ins
Les
son
plan
921
Uni
t: 9
Topi
c: H
eat a
nd
ener
gy
Teac
hing
obj
ecti
ves
Lea
rnin
g ou
tcom
es
Stud
ents
sho
uld
be a
ble
to:
Res
ourc
es/M
ater
ials
Act
ivit
ies/
CW
/HW
3.
Met
hods
of h
eat
tran
sfer
: con
vect
ion
•to
exp
lain
how
hea
t is
tran
sfer
red
by
conv
ectio
n
•to
des
crib
e co
nvec
tion
curr
ents
in
nat
ure
•ex
plai
n ho
w h
eat i
s tr
ansf
erre
d in
flui
ds
•de
scri
be th
e ro
le o
f co
nvec
tion
curr
ents
in
natu
re
Dia
gram
s of
land
an
d se
a br
eeze
s,
coni
cal f
lask
, cr
ysta
l of p
otas
sium
pe
rman
gana
te, s
tand
, bu
rner
, car
dboa
rd b
ox,
cand
le, p
aper
Rea
ding
: p 8
5, 8
6
Act
ivity
: 1, 2
, 3
CW
: Q1
(g)
HW
: Q1
(h)
Key
wor
ds: c
onve
ctio
n, w
ind,
ther
mal
, lan
d br
eeze
, sea
bre
eze
Met
hod:
Ask
: How
doe
s co
ol a
ir fr
om o
utsi
de e
nter
a r
oom
? H
ow d
oes
wat
er in
a p
an o
n th
e st
ove
beco
me
heat
ed?
Exp
lain
that
co
nvec
tion
occu
rs in
flui
ds w
hen
heat
is tr
ansf
erre
d fr
om o
ne p
art o
f a fl
uid
to a
noth
er w
ith th
e m
ovem
ent o
f the
flui
d its
elf.
With
ch
arts
and
dia
gram
s ex
plai
n th
e co
nvec
tion
curr
ents
in a
ir, a
nd in
liqu
ids.
Ask
: Hav
e yo
u be
en to
the
sea
coas
t? W
hat k
ind
of b
reez
e bl
ows
ther
e du
ring
the
day?
At n
ight
? E
xpla
in la
nd a
nd s
ea b
reez
es w
ith
the
help
of c
hart
s an
d di
agra
ms
on th
e bo
ard.
Dat
e:
Tim
e: 4
0 m
ins
Les
son
plan
93 1
Uni
t: 9
Topi
c: H
eat a
nd
ener
gy
Teac
hing
obj
ecti
ves
Lea
rnin
g ou
tcom
es
Stud
ents
sho
uld
be a
ble
to:
Res
ourc
es/M
ater
ials
Act
ivit
ies/
CW
/HW
4.
Rad
iatio
n •
to e
xpla
in h
ow h
eat i
s
tran
sfer
red
by r
adia
tion
•to
des
crib
e pr
actic
al
appl
icat
ions
of h
eat
tran
sfer
•ex
plai
n ho
w h
eat i
s tr
ansf
erre
d by
rad
iatio
n
•id
entif
y th
e pr
actic
al
appl
icat
ions
of r
adia
tion
Pic
ture
s of
shi
ny, d
ull,
blac
k, w
hite
sur
face
s,
diag
ram
of a
ther
mos
fla
sk, d
iagr
am o
f a
gree
nhou
se
Rea
ding
: p 8
6, 8
7
Act
ivity
: 5, 6
CW
: Q1
(i)
HW
: Q1
(j)
Key
wor
ds: r
adia
tion,
abs
orb,
ref
lect
, em
it, g
reen
hous
e, th
erm
os fl
ask,
vac
uum
Met
hod:
Ask
: Wha
t is
radi
atio
n? D
oes
radi
atio
n ne
ed a
med
ium
to tr
avel
in?
Exp
lain
that
rad
iatio
n do
es n
ot n
eed
a m
ediu
m to
tr
avel
in. T
hat i
s w
hy th
e he
at o
f the
Sun
can
trav
el th
roug
h sp
ace
to r
each
the
Ear
th.
Show
the
stud
ents
diff
eren
t typ
es o
f sur
face
. Exp
lain
that
a w
hite
sur
face
ref
lect
s m
ore
heat
, a b
lack
sur
face
abs
orbs
mor
e he
at.
Som
e su
rfac
es a
re b
ette
r at
abs
orbi
ng r
adia
tion
than
oth
ers.
Som
e su
rfac
es a
re b
ette
r at
em
ittin
g ra
diat
ion.
Ask
the
stud
ents
to m
ake
a lis
t of t
he s
urfa
ces
that
are
: goo
d ab
sorb
ers,
goo
d em
itter
s, g
ood
refle
ctor
s, b
ad a
bsor
bers
, bad
em
itter
s, b
ad r
efle
ctor
s.
Do
the
activ
ities
des
crib
ed o
n pa
ge 8
7.
Des
crib
e a
ther
mos
flas
k w
ith th
e he
lp o
f a d
iagr
am a
nd e
xpla
in h
ow it
hel
ps to
kee
p th
ings
col
d or
hot
.
Dat
e:
Tim
e: 4
0 m
ins
Les
son
plan
941
Uni
t: 9
Topi
c: H
eat a
nd
ener
gy
Teac
hing
obj
ecti
ves
Lea
rnin
g ou
tcom
es
Stud
ents
sho
uld
be a
ble
to:
Res
ourc
es/M
ater
ials
Act
ivit
ies/
CW
/HW
5.
Tem
pera
ture
•
to d
efin
e te
mpe
ratu
re
•to
exp
lain
how
to
mea
sure
tem
pera
ture
•to
exp
lain
tem
pera
ture
sc
ales
•to
des
crib
e di
ffere
nt
type
s of
ther
mom
eter
s
•to
exp
lain
how
to c
onve
rt
tem
pera
ture
sca
les
•ex
plai
n w
hat t
empe
ratu
re
is
•de
scri
be a
ther
mom
eter
an
d th
e te
mpe
ratu
re s
cale
s m
arke
d on
it
•de
scri
be d
iffer
ent t
ypes
of
ther
mom
eter
and
thei
r us
es
•co
nver
t tem
pera
ture
sca
les
Pic
ture
s of
diff
eren
t ki
nds
of th
erm
omet
er,
a cl
inic
al a
nd
a la
bora
tory
th
erm
omet
er, a
tabl
e of
te
mpe
ratu
re s
cale
s
Rea
ding
: p 8
8, 8
9
Act
ivity
: 8
CW
: Q2,
Q3,
Q4
HW
: Q1
(k)
(l)
(m)
Key
wor
ds: t
empe
ratu
re, t
herm
omet
er, c
apill
ary
tube
, Cel
sius
sca
le, F
ahre
nhei
t sca
le, K
elvi
n sc
ale,
abs
olut
e ze
ro, a
lcoh
ol
ther
mom
eter
, max
imum
and
min
imum
ther
mom
eter
, dig
ital t
herm
omet
er, e
lect
rica
l the
rmom
eter
Met
hod:
Ask
: Wha
t is
tem
pera
ture
? Wha
t is
the
norm
al te
mpe
ratu
re o
f the
hum
an b
ody?
How
is th
e no
rmal
bod
y te
mpe
ratu
re
mai
ntai
ned
at a
con
stan
t lev
el?
Exp
lain
that
tem
pera
ture
is th
e de
gree
of h
otne
ss o
f a b
ody.
It c
an b
e m
easu
red
usin
g a
ther
mom
eter
. Ask
: How
do
we
mea
sure
the
tem
pera
ture
of o
ur b
odie
s? E
xpla
in th
e us
es o
f the
rmom
eter
s. Sh
ow th
e st
uden
ts a
cl
inic
al a
nd a
labo
rato
ry th
erm
omet
er, a
nd d
emon
stra
te h
ow th
ey w
ork.
Wri
te th
e te
mpe
ratu
re s
cale
s on
the
boar
d, a
nd m
ark
the
uppe
r an
d lo
wer
lim
its. E
xpla
in th
e di
ffere
nces
bet
wee
n th
e sc
ales
and
exp
lain
abs
olut
e ze
ro, a
nd it
s us
e in
sci
entif
ic e
xper
imen
ts.
Show
the
stud
ents
pic
ture
s of
the
vari
ous
kind
s of
ther
mom
eter
and
exp
lain
thei
r us
e. W
ith th
e he
lp o
f for
mul
ae e
xpla
in h
ow
tem
pera
ture
sca
les
can
be c
onve
rted
.
Dat
e:
Tim
e: 4
0 m
ins
Les
son
plan
95 1
Unit 9: Heat and energy Worksheet 1
Name: Date:
1. Fill in the blanks to complete the text below.
Heat is a degree of . In scientific terms, heat is a type of energy
found in a body that has a temperature than its surroundings.
When an object is heated, its molecules energy and they start
moving . As they , they bump into
each other at a rate, and push the
in front of them. As this movement continues, travels from one
end of the object to the other.
2. Complete the table below by writing the correct temperatures.
Temperature scales Fahrenheit Celsius Kelvin
Melting point of ice
Boiling point of water
Human body temperature
Photocopiable material
961
Unit 9: Heat and energy Worksheet 2
Name: Date:
Q. Underline the correct word(s) in the sentences below.
1. Radiation is a particular way in which energy / electricity travels.
2. Radiation needs / does not need a medium to be carried.
3. Radiation can travel through solids / space.
4. The Earth is heated by the radiation from the Sun / Moon.
5. Clouds / Stars cut down some of the heat radiation reaching the Earth.
6. A white surface absorbs / reflects more heat.
7. A black surface absorbs / reflects more heat.
8. Good absorbers of heat radiation are good / bad emitters.
9. Dull black surfaces are the best emitters / absorbers of radiation.
10. Shiny silvery surfaces are the best / worst absorbers of radiation.
11. Dull black surfaces are the best / worst emitters of radiation.
12. Shiny, silvery surfaces are the best / worst emitters of radiation.
Photocopiable material
97 1
Teaching objectives:• to define refraction and explain how refraction is caused• to explain the effects of refraction with examples• to explain the laws of refraction with the help of an experiment• to describe what refractive index means• to explain what critical angle of refraction is• to show how to find the critical angle of glass and water by means of an experiment• to explain how total internal reflection is caused• to explain dispersion of light and describe it using a prism• to discuss primary colours and secondary colours• to show by an experiment that white light is made up of seven colours• to explain why objects appear coloured
Teaching strategy:Place a beaker of water on the desk. Dip one end of a pencil in it. Ask: Does the pencil seem straight? Can you tell why this happens? Explain that if we fill a tub with water, it appears shallower than it actually is. This is because when light travels from one transparent medium into another, it bends. This bending of light is called refraction. The bending of light occurs because when light rays pass into a denser medium, the speed of light slows down. When light passes into a thinner or rarer medium, its speed increases. Demonstrate the glass slab experiment, and help the students to perform the experiment with pins and a glass slab. Ask them to measure the angles of incidence and refraction. Ask: What do you see in the drawing? Explain that the rays of light go out of the block and bends at the surface. Your eyes see the rays after they have been bent. A ray of light is always refracted in a definite direction. As light passes from a dense material into a less dense material (e.g. from glass to air) it is bent away from the normal (the line drawn at right angles to the surface). As light goes into a more dense material (e.g. from air to glass) it bends towards the normal. Explain the laws of refraction.
Ask: What do you think would happen if you pass a beam of light through a rectangular block? Explain that the ray of light is refracted as it enters and leaves the block. The emerging ray is parallel to the incoming ray. Ask: When you look through the front of a fish tank, why does a fish look closer than it really is? Explain refraction using a diagram. Ask: Can you explain why refraction of light occurs? Explain that light waves travel at a speed of about 300,000 km/s in air, but they slow down when they enter any other material such as water or glass. If a ray of light meets the new material at an angle it bends. This is refraction. Discuss refractive index as the ratio of the speed of light in vacuum to the speed of light in a medium. The greater the speed of light the greater the change of
Dispersion of light
UNIT 10
981
direction. Ask: Why does a pool appear shallower than it actually is? Explain that one of the effects of refraction is that our brains can be tricked into thinking that pools are shallower or glass blocks are thinner than they actually are. The apparent depth is given by the real depth divided by the refractive index. The refractive index of water is about 4/3 so a 2 m pool only looks 1.5 m deep.
Ask: What is ‘critical angle’? Perform an experiment with a glass slab and pins to demonstrate the critical angle. You can see what happens when the angle of incidence inside a glass block increases from 35 to 50 degrees. At 35 degrees most of the light gets out of the glass with just a small part being reflected. At about 42 degrees the refracted ray just gets out of the block but much more of the light is being reflected. This is the ‘critical angle’. At angles greater than 42 degrees all the light is reflected. This is called total internal reflection. Explain that ‘critical angle’ is defined as the angle of incidence that provides an angle of refraction that is of 90 degrees, above which all the light is reflected and total internal reflection occurs. Discuss the uses of total internal reflection in optical instruments and optical fibres. Explain that optical fibres can also carry coded signals as pulses of light from a laser. These can be changed into electrical signals at the receiving end. For example many of our telephone calls are now transmitted down light which can carry several thousand conversations at once! Glass fibres are more efficient at transmitting messages than copper wires and so fewer booster stations are needed. this keeps costs low.
Ask: What is coloured light? How do we see colours? Discuss coloured light and primary and secondary colours. Explain how we can see coloured objects. Discuss the mixing of pigments and the use of filters to see coloured objects. Help the students to mix coloured lights and paints to see for themselves how we can see coloured objects. Make a colour viewing box.
Summarize the lesson.
Answers to Exercises in Unit 101. (a) 300,000 km
(b) Light waves travel at a speed of about 300,000 km/s in air, but they slow down when they enter another transparent material such as water or glass. If a ray of light meets the new material at an angle, it bends. This bending of light is called ‘refraction’.
(c) The ratio of the speed of light in a vacuum to the speed of light in the material is called the refractive index of the material.
refractive index = speed of light in vacuumspeed of light in material
(d) refractive index = speed of light in vacuum / speed of light in medium
1.33 = 300,000 / ?
? = 300,000 / 1.33
speed of light in medium = 225,000 km/s (the medium is water)
(e) This happens because light bends as it passes from one transparent material to another.
A ray of light is always refracted in a definite direction. As light passes from water to air it bends away from the normal. As light goes into a denser material it bends towards the normal.
(f) Glass prisms can act like perfect mirrors if light rays strike an inside face at an angle greater than its critical angle.
Unit 10 Dispersion of light
99 1
Amazing Science TG 7
(g) Critical angle is defined as the angle of incidence that provides an angle of refraction that is of
90 degrees, above which all the light is reflected and total internal reflection occurs.
When the angle of incidence inside a glass block increases from 35 to 50 degrees. At 35 degrees most of the light gets out of the glass with just a small part being reflected. At about 42 degrees the refracted ray just gets out of the block but much more of the light is being reflected. This is the ‘critical angle’. At angles greater than 42 degrees all the light is reflected. This is called total internal reflection.
2. Refer to Pupil’s Book.
3. Optical fibres are thin fibres of glass through which light can pass. They are bundled together and used as a ‘light pipe’. Light hits the sides of the fibres at an angle greater than the critical angle. All the light is reflected and it emerges from the other end of the fibres almost as bright as when it went in.
Optical fibres can be used for inspection inside machines and even inside the human body. Optical fibres can carry coded signals as pulses of light from a laser. They can be changed into electrical signals at the receiving end. They are used to transmit telephone signals.
4. Refer to Pupil’s Book.
5. (a) red (b) blue
6. Objects appear coloured because the materials that they are made of absorb some of the colours of the spectrum and reflect the rest. As a result we only see the colours of the reflected light. The petals reflect yellow light and the leaves reflect green light.
7. Primary colours: white, yellow, magenta, cyan Primary pigments: green, purple, orange
Additional Exercise
MCQs
(a) The bending of light waves when passing from a one transparent medium to another is called .
reflection refraction dispersion [refraction]
(b) When a ray of light passes from a rarer to a denser medium it bends from the normal.
away towards like a wave [towards]
(c) The angle which the incident ray makes with the medium is called the angle of .
incidence refraction reflection [incidence]
(d) The ratio of the speed of light in air to the speed of light in a medium is called index.
reflective refractive objective [refractive]
1001
(e) The size of the angle of incidence at which the refracted ray runs parallel to the surface of the medium is called .
angle of incidence angle of refraction critical angle [critical angle]
(f) Very thin fibres of glass through which light can pass are called .
fibre glass fibres optical fibres [optical fibres]
(g) The splitting of light when it passes through a prism is called .
refraction reflection dispersion [dispersion]
(h) Red, blue, and green are called colours.
primary secondary plastic [primary]
(i) Cyan, magenta, and are secondary colours.
blue green yellow [yellow]
(j) Objects appear coloured because they reflect or some of the colours of the spectrum.
absorb disperse refract [absorb]
Unit 10 Dispersion of light
101 1
Uni
t: 1
0
Topi
c: D
ispe
rsio
n of
ligh
t
Teac
hing
obj
ecti
ves
Lea
rnin
g ou
tcom
es
Stud
ents
sho
uld
be a
ble
to:
Res
ourc
es/M
ater
ials
Act
ivit
ies/
CW
/HW
1.
Ref
ract
ion
of
light
•to
def
ine
refr
actio
n
•to
exp
lain
ref
ract
ive
inde
x
•to
des
crib
e re
al a
nd
appa
rent
dep
th
•ex
plai
n ho
w r
efra
ctio
n oc
curs
•de
scri
be r
efra
ctiv
e in
dex
•di
stin
guis
h be
twee
n re
al
and
appa
rent
dep
th
Gla
ss s
lab,
pin
s,
trou
gh o
f wat
er, a
st
one,
bea
ker,
penc
il
Rea
ding
: p 9
4, 9
5
Act
ivity
: 1
CW
: Q1
(a)
(b)
HW
: Q1
(c)
(d)
(e)
Key
wor
ds: r
efra
ctio
n, r
efra
ctiv
e in
dex,
rea
l dep
th, a
ppar
ent d
epth
Met
hod:
Pla
ce o
ne e
nd o
f a p
enci
l in
a be
aker
of w
ater
.
Ask
: Doe
s th
e pe
ncil
appe
ar s
trai
ght?
Can
you
exp
lain
why
this
hap
pens
? E
xpla
in th
at w
hen
light
pas
ses
from
one
med
ium
into
an
othe
r it
bend
s. T
his
bend
ing
of li
ght i
s ca
lled
refr
actio
n. T
he b
endi
ng o
f lig
ht r
ays
occu
rs b
ecau
se w
hen
light
ray
s pa
ss in
to a
de
nser
med
ium
, the
spe
ed o
f lig
ht s
low
s do
wn.
Whe
n lig
ht p
asse
s fr
om a
den
ser
to a
rar
er o
r th
inne
r m
ediu
m, i
ts s
peed
incr
ease
s.
Dem
onst
rate
the
glas
s sl
ab a
ctiv
ity d
escr
ibed
on
page
94
and
help
the
stud
ents
to s
et u
p th
e ex
peri
men
t the
mse
lves
and
mea
sure
th
e an
gle
of in
cide
nce.
Ask
: Wha
t do
you
see
in th
e dr
awin
g? E
xpla
in th
at th
e ra
ys o
f lig
ht g
o ou
t of t
he b
lock
and
ben
d at
the
surf
ace.
You
r ey
es s
ee th
e ra
ys a
fter
they
hav
e be
nt. A
s lig
ht p
asse
s fr
om a
den
se m
ater
ial i
nto
a le
ss d
ense
mat
eria
l (fr
om g
lass
to a
ir)
it be
nds
away
from
the
norm
al r
ay w
hich
is p
erpe
ndic
ular
to th
e su
rfac
e. A
s lig
ht g
oes
into
a m
ore
dens
e m
ater
ial (
from
air
to g
lass
) it
bend
s to
war
ds th
e no
rmal
. Exp
lain
the
law
s of
ref
ract
ion.
Ask
: Wha
t is
the
spee
d of
ligh
t? D
iscu
ss r
efra
ctiv
e in
dex
as a
rat
io o
f the
spe
ed o
f lig
ht to
the
spee
d of
ligh
t in
a m
ediu
m. T
he
grea
ter
the
spee
d of
ligh
t, th
e gr
eate
r th
e ch
ange
of d
irec
tion.
Ask
: Why
doe
s a
pool
app
ear
shal
low
er th
an it
act
ually
is?
Exp
lain
that
one
of t
he e
ffect
s of
ref
ract
ion
is th
at o
ur b
rain
s ca
n be
tr
icke
d in
to th
inki
ng th
at p
ools
are
sha
llow
er o
r gl
ass
bloc
ks a
re th
inne
r th
an th
ey a
ctua
lly a
re. T
he r
eal d
epth
can
be
calc
ulat
ed
by m
ultip
lyin
g th
e ap
pare
nt d
epth
by
the
refr
activ
e in
dex
of th
e m
ediu
m. T
he r
efra
ctiv
e in
dex
of w
ater
is a
bout
4/3
, so
a po
ol 2
m
etre
s de
ep a
ppea
rs to
be
only
1.5
met
res
deep
.
Dat
e:
Tim
e: 4
0 m
ins
Les
son
plan
1021
Uni
t: 1
0
Topi
c: D
ispe
rsio
n of
ligh
t
Teac
hing
obj
ecti
ves
Lea
rnin
g ou
tcom
es
Stud
ents
sho
uld
be a
ble
to:
Res
ourc
es/M
ater
ials
Act
ivit
ies/
CW
/HW
2.
Cri
tical
ang
le
T
otal
inte
rnal
re
flect
ion
•to
def
ine
criti
cal a
ngle
•to
des
crib
e to
tal
inte
rnal
ref
lect
ion
•de
fine
criti
cal a
ngle
•de
scri
be to
tal i
nter
nal
refle
ctio
n
•ex
plai
n ho
w to
tal i
nter
nal
refle
ctio
n is
use
ful
Gla
ss b
lock
, lam
p,
pris
m, p
ictu
res
of
optic
al fi
bre
and
peri
scop
e
Rea
ding
: p
95, 9
6
Act
ivity
: 2
CW
: Q2,
Q3
HW
: Q1
(f)
((g)
Key
wor
ds: c
ritic
al a
ngle
, tot
al in
tern
al r
efle
ctio
n, o
ptic
al fi
bre,
per
isco
pe
Met
hod:
Ask
: Wha
t is
criti
cal a
ngle
? Pe
rfor
m a
n ex
peri
men
t with
a g
lass
sla
b an
d pi
ns to
dem
onst
rate
the
criti
cal a
ngle
of g
lass
. E
xpla
in th
at y
ou c
an s
ee w
hat h
appe
ns w
hen
the
angl
e of
inci
denc
e in
side
a g
lass
blo
ck in
crea
ses
from
35
to 5
0 de
gree
s. A
t 35
degr
ees
mos
t of t
he li
ght g
ets
out o
f the
gla
ss w
ith ju
st a
sm
all p
art b
eing
ref
lect
ed. A
t abo
ut 4
2 de
gree
s th
e re
frac
ted
ray
just
get
s ou
t of t
he b
lock
, but
muc
h m
ore
of th
e lig
ht is
ref
lect
ed. T
his
is th
e cr
itica
l ang
le. A
t ang
les
grea
ter
than
42
degr
ees
all t
he li
ght i
s re
flect
ed. T
his
is c
alle
d to
tal i
nter
nal r
efle
ctio
n.
Def
ine
criti
cal a
ngle
as
the
angl
e of
inci
denc
e th
at p
rovi
des
an a
ngle
of r
efra
ctio
n of
90
degr
ees,
bey
ond
whi
ch a
ll th
e lig
ht is
re
flect
ed a
nd to
tal i
nter
nal r
efle
ctio
n oc
curs
. Dis
cuss
how
cri
tical
ang
les
of g
lass
are
use
d in
opt
ical
inst
rum
ents
and
how
opt
ical
fib
res
are
used
for
insp
ectio
n in
side
mac
hine
s an
d ev
en in
side
the
hum
an b
ody.
Opt
ical
fibr
es c
an a
lso
carr
y co
ded
sign
als
as
puls
es o
f lig
ht fr
om a
lase
r. T
hese
can
be
chan
ged
into
ele
ctri
cal s
igna
ls a
t the
rec
eivi
ng e
nd. M
any
of o
ur te
leph
one
calls
are
no
w tr
ansm
itted
thro
ugh
optic
al fi
bres
whi
ch c
an c
arry
sev
eral
thou
sand
con
vers
atio
ns a
t onc
e. G
lass
fibr
es a
re m
ore
effic
ient
at
tran
smitt
ing
mes
sage
s th
an c
oppe
r w
ires
and
so
few
er b
oost
er s
tatio
ns a
re n
eede
d an
d th
is k
eeps
the
cost
s lo
w.
Dat
e:
Tim
e: 4
0 m
ins
Les
son
plan
103 1
Uni
t: 1
0
Topi
c: D
ispe
rsio
n of
ligh
t
Teac
hing
obj
ecti
ves
Lea
rnin
g ou
tcom
es
Stud
ents
sho
uld
be a
ble
to:
Res
ourc
es/M
ater
ials
Act
ivit
ies/
CW
/HW
3.
Col
ours
•
to d
iscu
ss c
olou
rs
•to
iden
tify
prim
ary
and
seco
ndar
y co
lour
s
•to
exp
lain
why
obj
ects
ap
pear
col
oure
d
•to
exp
lain
pig
men
ts
and
filte
rs
•ex
plai
n th
at w
hite
ligh
t is
com
pose
d of
sev
en c
olou
rs
•ex
plai
n co
lour
ed li
ght
•ex
plai
n pi
gmen
ts a
nd
filte
rs
Pri
sm, t
orch
, col
oure
d lig
hts,
pai
nts,
col
oure
d fil
ters
Rea
ding
: p 9
6, 9
7, 9
8
Act
ivity
: 3, 4
CW
: Q4,
Q5
HW
: Q6,
Q7
Key
wor
ds: c
olou
r, di
sper
sion
, spe
ctru
m, p
rim
ary
and
seco
ndar
y co
lour
, sen
sors
, pig
men
t, fil
ter
Met
hod:
Ask
: Wha
t is
colo
ured
ligh
t? H
ow d
o w
e se
e co
lour
s?
Exp
lain
col
oure
d lig
ht a
nd p
rim
ary
and
seco
ndar
y co
lour
s w
ith th
e he
lp o
f cha
rts
and
prac
tical
dem
onst
ratio
ns. E
xpla
in h
ow w
e se
e th
e co
lour
s of
obj
ects
. Obj
ects
app
ear
colo
ured
bec
ause
the
mat
eria
ls th
ey a
re m
ade
of a
bsor
b so
me
colo
urs
of th
e sp
ectr
um
and
refle
ct th
e re
st.
Ask
: Wha
t are
pai
nts,
ink,
and
cra
yons
mad
e of
? Why
do
they
app
ear
colo
ured
? E
xpla
in th
at p
igm
ents
are
che
mic
al s
ubst
ance
s w
hich
ref
lect
som
e co
lour
s on
ly. O
ur s
kin,
leav
es a
nd p
etal
s of
pla
nts,
all
cont
ain
pigm
ents
. Exp
lain
by
prac
tical
dem
onst
ratio
ns
the
mix
ing
of p
igm
ents
to p
rodu
ce a
wid
e ra
nge
of c
olou
rs.
Show
the
stud
ents
filte
rs o
f diff
eren
t col
ours
. Ask
them
to lo
ok th
roug
h th
e fil
ters
and
say
wha
t col
ours
they
can
see
. Exp
lain
that
fil
ters
allo
w s
ome
colo
urs
to p
ass
thro
ugh,
and
filte
r ou
t all
the
othe
rs. F
or e
xam
ple
a gr
een
leaf
look
s bl
ack
if w
e ob
serv
e it
thro
ugh
a re
d fil
ter.
Thi
s is
bec
ause
the
filte
r ha
s ab
sorb
ed th
e gr
een
colo
ur a
nd th
ere
is n
o gr
een
light
to r
efle
ct.
Dat
e:
Tim
e: 4
0 m
ins
Les
son
plan
1041
Unit 10: Dispersion of light Worksheet 1
Name: Date:
1. Using the formula: refractive index = speed of light in vacuum/speed of light in a material, calculate the speed of light in the given materials.
Material Refractive index Speed of light in vacuum ( 300,000 km/ s)
Air 1.00
Water 1.33
Glass 1.51
2. What colour will you see when:
a. red light falls on a red surface?
b. blue light falls on a red surface?
c. magenta light falls on a red surface?
d. red light falls on a cyan surface?
e. magenta light falls on a cyan surface?
f. yellow light falls on a cyan surface?
Photocopiable material
105 1
Unit 10: Dispersion of light Worksheet 2
Name: Date:
1. Fill in the blanks to complete the text about pigments.
Pigments are which reflect only certain colours.
is an example of a pigment. Petals, leaves, and animal skins also
contain . There are primary pigment
colours, , , . We
can produce a wide range of colours by __________________ pigments, this is because they do
not reflect only
colour, but a small part of the .
2. Complete the table below.
Colours of pigments Colour produced
red + blue
yellow + red
blue + yellow
red + blue
red + blue + yellow
3. Fill in the blanks to complete the text.
A filter is a piece of glass or plastic which allows some colours to
pass through, but out all the others. A leaf looks green because
it reflects light. If we look at it in red light it will look
. This is because there is no light to reflect.
4. What will be the colour of white light when it is passed through the filters listed below?
Colour of the filter Colour of light
red
green
blue
Photocopiable material
1061
Teaching objectives:• to define the terms wavelength, frequency, and amplitude• to describe the factors which are essential for producing sound• to discuss the audible frequency range of humans and other animals• to explain how to design a musical instrument• to discuss the application of different sounds in daily life
Teaching strategy:Ask: What kinds of sounds can you hear in a busy street? Which kind of sound do you like? Make a pendulum by tying a bob to a piece of string. Pull it to one side to make it swing. Explain that the to and fro movement that takes to complete one oscillation is called a period. Count the number of oscillations that the pendulum makes in one minute. Calculate the number of oscillations in one second. Explain that the number of oscillations completed in one second is called the frequency of the oscillation. Draw a pendulum on the board. Explain the mean and extreme position of the bob. The distance that the bob travels from the centre to the extreme position is called its amplitude.
Tie a rope to a fixed point. Move the free end from side to side. Explain that a transverse wave is being made. Fix a soft spring at one end and pull it backwards and forwards, waves will travel along the spring. Sections of the spring will be compressed and others will be loose. Explain that the tight coil of the spring is called a compression and the loose coil is called a rarefaction. Such waves are called longitudinal waves. Sound waves are also made in this way. Sound waves are longitudinal waves, which are produced by a vibrating body. Compressions and rarefaction produced by vibrating bodies produce sound waves that travel in air.
Ask: Do you know the speed of sound? What is the speed of light? Which travels faster, sound or light? How do you know? Explain that during a thunderstorm the flash of lightning can be seen before the clap of thunder. Take two balloons and inflate them. Heat one of the balloons till it bursts. Prick the cold balloon with a pin at the same time. Ask: Which balloon made a louder sound? Explain that sound waves travel faster in hot air. Ask: Can you hear sound through a door? Explain that sound waves need a medium to travel in. Sound can travel in solids, liquids, and gases. The denser the medium, the faster the waves will travel. Explain the experiment of an electric bell in a jar. The sound of the ringing bell will gradually decrease as the air is evacuated from the jar, this happens because sound waves cannot be produced without a medium.
Ask: Which will produce a louder sound, a small drum struck lightly or a big drum struck strongly? Explain that the amplitude of the vibrations produced by the bigger drum will be large and so a louder
Oscillations and waves
UNIT 11
107 1
sound will be produced. Also the bigger drum has a larger surface area; therefore it will produce a louder sound than the smaller drum. Explain the activity at the end of the lesson in which the cone is being used to carry sound waves. Ask: Can you hear a louder sound if you stand near a vibrating body or if you are away from it? Explain that sound waves spread in all directions, and the sound becomes weaker as the distance from the vibrating body increases.
Ask: What is the difference between the sound of a whistle and that of a buzzer? Explain that the sound of a whistle is shrill because it has a high pitch. The pitch of the sound depends on the frequency of the sound waves produced by a vibrating body. A fast vibrating body has a high frequency. It produces a shrill sound.
Send two children out of the class. Tell them to say ‘hello’ from behind the door. Ask: Can you tell who said ‘hello’ first? Explain that voices and sounds of musical instruments can be recognized by their timbre. Timbre is the combination of sound waves of different frequencies which collectively make up a particular sound.
Ask: What can you hear when you clap or shout in an empty hall? Why does your voice resound? Explain that when sound waves strike a hard surface, they are reflected back. This reflection of sound is called an echo. Explain how echoes are used in echo sounders in ships to calculate the depth of the sea. Explain how bats use echoes to detect obstructions in the dark. Ask: How do you feel in a crowded room where everyone is talking? Why do little children begin to cry in a noisy room? What is noise? Explain that noise is an abrupt change in the frequency and amplitude of sound waves. Noise is a kind of pollution that can produce harmful effects in the body. It can cause headache and even deafness.
Summarize the lesson.
Answers to Activities1. Yes2. The pieces of paper bob up and down. The waves move towards the edge of the basin.
Answers to Exercises in Unit 111. (a) A to and fro movement is called an oscillation. (b) The time taken for one complete oscillation is called a period. (c) The number of oscillations that are completed in one second is the frequency of the oscillation.
It can also be described as the number of waves passing every second. A frequency of 100 Hz means that 100 waves are passing every second.
For example if the period of a pendulum is ½ a second, it will make two complete swings in 1 second.
2. frequency = 1 / period a period = to time taken for 1 oscillation frequency = number of oscillations in one second 5min = 5 x 60 = 300 s period of oscillation = 300 / 100 = 3 s
3. The period of oscillation in seconds is = 28days x 24 hrs x 60 min x 60 s = 2419200 s
4. Its period is too long. The pendulum should be made shorter.
Amazing Science TG 7
1081
5. Waves can be transverse or longitudinal. Transverse waves are produced when the oscillation is from side to side at right angles to the direction in which the wave travels.
If one end of a spring is fixed to a wall and the other end is pulled backwards and forwards, a wave will be seen travelling along the spring. Each wave is a compressed section followed by a stretched-out section. Waves produced by these backward and forward movements are called longitudinal waves. The wave on the spring and sound waves are longitudinal waves. The oscillations producing them are in the same direction as the motion of the wave. The squashes are called compressions and the stretches are called rarefactions.
6. A, A, D, C
7. Using the formula: speed = frequency x wavelength
wave speed frequency wavelength1 32 m/s 8 Hz 4 m2 32 m/s 16 Hz 2 m3 32 m/s 32 Hz 1m
8. (i) B (ii) A (iii) C
9. The loudness of sound depends on the amplitude of the vibrating body. If the amplitude is large, a loud sound will be heard. The loudness of sound also depends on the surface area of the vibrating body. A small drum will produce a softer sound than a big one.
10. Electric doorbell
When the switch of the doorbell is pressed the circuit is closed and the current begins to flow through a solenoid. The hammer begins to vibrate striking the gong and the bell continues to ring as long as the push button is pressed.
Smoke detector
All smoke detectors consist of two basic parts–a ‘sensor’ to sense the smoke and a very loud electric horn to wake up people in case of fire.
Radio
At the radio station the sound waves of a program go into a microphone that has an electric current running through it. These sound waves create vibrations in the current as they travel through wires to the control room. In the control room technicians control their volume and send them out through a transmitter. An antenna on the transmitter sends these electrical waves out through the air as radio waves.
The radio in your home has an antenna that picks up these waves from many stations at the same time. By turning the tuning dial you can select the station you want to listen to.
Television
A television station broadcasts a program by converting a sound and video program into a radio frequency. A television set receives these signals and turns them into sound and video by converting the radio frequency into an image.
Safety alarm
Safety alarms are electric alarms which are used to indicate the opening of a door or window or detect motion using infrared waves. These types of sensors are designed for indoor use.
Unit 11 Oscillations and waves
109 1
Amazing Science TG 7
Additional Exercise
MCQs
(a) The regular to and fro movements of a swinging body are called .
waves oscillations movements [oscillations]
(b) The time taken for one complete oscillation is called .
period wave requency [period]
(c) The number of oscillations completed in one second is called .
frequency period wave [frequency]
(d) Frequency is measured in .
seconds hertz ohms [hertz]
(e) The loudness of sound produced by a vibrating body depends on its .
amplitude oscillations frequency [amplitude]
(f) Waves that travel perpendicular to the direction of the oscillations are called .
longitudinal waves transverse waves vibrations [transverse waves]
(g) Sound waves are waves.
transverse longitudinal horizontal [longitudinal]
(h) A small drum will produce a sound than a big one.
louder softer shriller [softer]
(i) Humans can hear sound of frequencies between .
50 to 20,000 Hz 500 to 50,000 Hz 500 to 66,000 Hz [50 to 20,000 Hz]
(j) Wavelength is the distance between two .
waves wavefront oscillations [wavefronts]
1101
Uni
t: 1
1
Topi
c: O
scil
lati
ons
and
wav
es
Teac
hing
obj
ecti
ves
Lea
rnin
g ou
tcom
es
Stud
ents
sho
uld
be a
ble
to:
Res
ourc
es/M
ater
ials
Act
ivit
ies/
CW
/HW
1.
Osc
illat
ion,
pe
riod
, and
fr
eque
ncy
•to
exp
lain
osc
illat
ion,
pe
riod
, and
freq
uenc
y•
defin
e th
e te
rms
osci
llatio
n, p
erio
d, a
nd
freq
uenc
y
A p
endu
lum
, a m
etre
ru
le, a
sto
pwat
chR
eadi
ng: p
103
Act
ivity
: 1
CW
: Q2,
Q3,
Q4
HW
: Q1
(a)
(b)
(c)
Key
wor
ds: o
scill
atio
n, p
erio
d, fr
eque
ncy,
her
tz, a
mpl
itude
Met
hod:
Ask
: Wha
t kin
ds o
f sou
nd c
an y
ou h
ear
in a
bus
y st
reet
? Whi
ch s
ound
s do
you
like
? M
ake
a pe
ndul
um b
y ty
ing
a bo
b to
a
piec
e of
str
ing.
Pul
l it t
o on
e si
de to
mak
e it
swin
g. E
xpla
in th
at th
e to
and
fro
mov
emen
t tha
t it t
akes
to c
ompl
ete
one
osci
llatio
n is
ca
lled
a pe
riod
. Cal
cula
te th
e nu
mbe
r of
osc
illat
ions
in o
ne s
econ
d. E
xpla
in th
at th
e nu
mbe
r of
osc
illat
ions
com
plet
ed in
one
sec
ond
is c
alle
d th
e fr
eque
ncy
of th
e os
cilla
tion.
Dra
w a
pen
dulu
m o
n th
e bo
ard.
Exp
lain
the
mea
n an
d ex
trem
e po
sitio
ns o
f the
bob
. The
dis
tanc
e th
at th
e bo
b tr
avel
s fr
om th
e ce
ntre
to th
e ex
trem
e po
sitio
n is
cal
led
its a
mpl
itude
.
Dat
e:
Tim
e: 4
0 m
ins
Les
son
plan
111 1
Uni
t: 1
1
Topi
c: O
scil
lati
ons
and
wav
es
Teac
hing
obj
ecti
ves
Lea
rnin
g ou
tcom
es
Stud
ents
sho
uld
be a
ble
to:
Res
ourc
es/M
ater
ials
Act
ivit
ies/
CW
/HW
2.
Wav
es
•to
def
ince
wav
es
•to
des
crib
e th
e di
ffere
nt
kind
s of
wav
e
•de
scri
be w
aves
•id
entif
y di
ffere
nt k
inds
of
wav
e
Rop
e, s
prin
gR
eadi
ng: p
104
Act
ivity
: 2
CW
: Q6,
Q8
HW
: Q5,
Q7
Key
wor
ds: w
ave,
tran
sver
se w
ave,
long
itudi
nal w
ave,
com
pres
sion
, rar
efac
tion,
wav
efro
nt, w
ave
leng
th, p
eak,
trou
gh
Met
hod:
Tie
a r
ope
to a
fixe
d po
int.
Mov
e th
e fr
ee e
nd fr
om s
ide
to s
ide.
Exp
lain
that
a tr
ansv
erse
wav
e is
bei
ng m
ade.
Fix
a s
oft s
prin
g at
one
end
and
pul
l it b
ackw
ards
and
forw
ards
. You
will
see
that
wav
es w
ill tr
avel
alo
ng th
e sp
ring
. Sec
tions
of t
he
spri
ng w
ill b
e co
mpr
esse
d an
d ot
hers
will
be
loos
e. E
xpla
in th
at th
e tig
ht c
oil o
f the
spr
ing
is c
alle
d a
com
pres
sion
and
the
loos
e co
il is
cal
led
a ra
refa
ctio
n. S
uch
wav
es a
re c
alle
d lo
ngitu
dina
l wav
es.
Soun
d w
aves
are
als
o m
ade
in th
is w
ay. S
ound
wav
es a
re lo
ngitu
dina
l wav
es w
hich
are
pro
duce
d by
a v
ibra
ting
body
. Com
pres
sion
s an
d ra
refa
ctio
ns p
rodu
ced
by v
ibra
ting
bodi
es p
rodu
ce s
ound
wav
es th
at tr
avel
in a
ir.
Dra
w a
dia
gram
of a
wav
e on
the
boar
d. M
ark
the
cres
t and
the
trou
gh. E
xpla
in th
at w
ave
leng
th is
the
dist
ance
bet
wee
n tw
o pe
aks
or tw
o tr
ough
s (w
avef
ront
s). T
he s
peed
of a
wav
e te
lls u
s ho
w fa
r ea
ch w
ave
fron
t mov
es in
one
sec
ond.
The
spe
ed c
an b
e ca
lcul
ated
by
the
dist
ance
trav
elle
d by
a w
ave
divi
ded
by th
e tim
e ta
ken.
Dat
e:
Tim
e: 4
0 m
ins
Les
son
plan
1121
Uni
t: 1
1
Topi
c: O
scil
lati
ons
and
wav
es
Teac
hing
obj
ecti
ves
Lea
rnin
g ou
tcom
es
Stud
ents
sho
uld
be a
ble
to:
Res
ourc
es/M
ater
ials
Act
ivit
ies/
CW
/HW
3.
Fre
quen
cy a
nd
pitc
h
C
hara
cter
istic
s of
so
und
•to
def
ine
freq
uenc
y an
d pi
tch
of s
ound
•to
des
crib
e ch
arac
teri
stic
s of
sou
nd
•to
des
crib
e fr
eque
ncy
rang
es o
f diff
eren
t an
imal
s
•ex
plai
n ho
w fr
eque
ncy
and
pitc
h of
a s
ound
are
re
late
d
•de
scri
be th
e ch
arac
teri
stic
s of
sou
nd
•de
scri
be th
e fr
eque
ncy
rang
es o
f som
e an
imal
s
A ta
ble
of fr
eque
ncy
and
pitc
h
A ta
ble
of th
e fr
eque
ncy
rang
e of
so
unds
pro
duce
d by
di
ffere
nt a
nim
als
Rea
ding
: p 1
05
Act
ivity
: 3
HW
: Q9
Key
wor
ds: f
requ
ency
, pitc
h, a
mpl
itude
, vib
ratio
n, lo
ud s
oft,
freq
uenc
y ra
nge,
her
tz
Met
hod:
Ask
: Wha
t is
the
diffe
renc
e be
twee
n th
e so
und
of a
whi
stle
and
that
of a
buz
zer?
Exp
lain
that
the
soun
d of
a w
hist
le
is s
hrill
bec
ause
it h
as a
hig
h pi
tch.
The
pitc
h of
a s
ound
dep
ends
on
the
freq
uenc
y of
the
soun
d w
aves
pro
duce
d by
a v
ibra
ting
body
. A fa
st v
ibra
ting
body
pro
duce
s a
shri
ll so
und.
Ask
: Whi
ch w
ill p
rodu
ce a
loud
er s
ound
, a s
mal
l dru
m s
truc
k lig
htly
or
a bi
g dr
um s
truc
k st
rong
ly?
Exp
lain
that
the
ampl
itude
of
the
vibr
atio
ns p
rodu
ced
by th
e bi
gger
dru
m w
ill b
e la
rge
and
so a
loud
er s
ound
will
be
prod
uced
. Als
o th
e bi
gger
dru
m h
as a
la
rger
sur
face
are
a, th
eref
ore
it w
ill p
rodu
ce a
loud
er s
ound
than
the
smal
ler
drum
.
Show
the
stud
ents
the
tabl
e of
the
freq
uenc
y ra
nges
of a
nim
al s
ound
s an
d di
scus
s th
em.
Dat
e:
Tim
e: 4
0 m
ins
Les
son
plan
113 1
Uni
t: 1
1
Topi
c: O
scil
lati
ons
and
wav
es
Teac
hing
obj
ecti
ves
Lea
rnin
g ou
tcom
es
Stud
ents
sho
uld
be a
ble
to:
Res
ourc
es/M
ater
ials
Ass
ignm
ents
/HW
4.
App
licat
ions
of
soun
d in
dai
ly li
fe
•to
dis
cuss
the
appl
icat
ions
of s
ound
in
dai
ly li
fe
•ex
plai
n ho
w w
e m
ake
the
use
of s
ound
in o
ur d
aily
liv
es
Pic
ture
s of
an
elec
tric
do
orbe
ll, e
lect
ric
sire
n, te
leph
one,
rad
io
and
ster
eo p
laye
r, te
levi
sion
, sm
oke
dete
ctor
, saf
ety
alar
m
Rea
ding
: p 1
06
Pro
ject
: p 1
07
HW
: Q10
Key
wor
ds: e
lect
rica
l app
lianc
e
Met
hod:
Sho
w th
e st
uden
ts p
ictu
res
of a
pplia
nces
that
pro
duce
sou
nd. D
escr
ibe
the
appl
icat
ions
of e
lect
rica
l app
lianc
es s
uch
as
elec
tric
doo
rbel
ls, s
iren
s, te
leph
ones
, tel
evis
ion,
etc
. tha
t we
use.
Dis
cuss
noi
se p
ollu
tion
and
its h
arm
ful e
ffect
s, a
nd a
lso
the
way
s in
whi
ch w
e ca
n tr
y to
red
uce
nois
e po
llutio
n.
Dat
e:
Tim
e: 4
0 m
ins
Les
son
plan
1141
Unit 11: Oscillations and waves Worksheet 1
Name: Date:
Q. Fill in the blanks to complete the sentences below.
a. The to and fro movement of a pendulum is called .
b. The time taken for one complete oscillation is a .
c. The number of oscillations completed in one second is called .
d. The number of waves passing every second is called .
e. Frequency is measured in .
f. A Hertz is equal to .
g. The size of the oscillation is called .
h. Oscillations can be used to make .
i. Side to side oscillations at right angles to the direction in which the wave travels are called
.
j. Oscillations that are in the same direction as the motion of the wave are called
.
Photocopiable material
115 1
Unit 11: Oscillations and waves Worksheet 2
Name: Date:
1. Mark the amplitude of the pendulum shown in the diagram.
2. Draw a line to the frequency range in Hz of the following:
Animal Frequency range (Hz) of the sound produced
human 500 to 4000
dog 500 to 5000
cat 4000 to 100,000
porpoise 500 to 2500
grasshopper 12000 to 120,000
rat 800 to 120,000
a. Which animal can produce the loudest sound?
b. What is its frequency range?
c. Which animal produces the softest sound?
d. What is its frequency range?
Photocopiable material
1161
Teaching objectives:• to explain what an electric current is• to describe an electric circuit• to show how to connect a circuit in parallel and in series• to explain the disadvantages of a circuit connected in series• to explain the safety measures to be taken when using electricity• to identify the units for measuring current• to describe the different devices used for measuring current• to discuss the domestic uses of electricity in the home
Teaching strategy:Ask: What is lightning? Have you seen tiny sparks coming from a nylon shirt when you take it off in the dark? Why do nylon or silk clothes stick to our legs when we walk? Explain how static electricity is produced. Rub a plastic comb with a woollen cloth and bring it near tiny bits of paper. Ask: What happens? Why? Explain that opposite charges are produced due to the rubbing off of electrons from one material on to another. That is how clouds become charged. Explain that when the amount of opposite charges in two bodies becomes large, electrons jump from one to the other and sparks are produced. A streak of lightning is a huge spark of electricity.
Ask: What is electricity? What is an electric current? Explain that an electric current is a flow of electrons, and that electric currents are produced by fish such as eels and electric rays. Our body also produces electric currents to make our heart and brain work. Explain the uses of electricity in our daily lives. Ask: Why are electric wires coated with plastic or rubber? Why are electric plugs made of plastic? Explain the difference between conductors and insulators.
Set up a simple circuit. Show the students that the bulb lights up. Detach a wire from the battery. Ask: Why did the bulb go off? Explain the formation of complete and incomplete circuits and the use of a switch in a circuit. Show the students a battery cell. Break it open and show them the inside. Draw a battery cell on the board. Explain the parts. Ask: Have you seen a liquid paste coming out of cells that have been lying around? Explain that a chemical substance called an electrolyte is used in batteries. An electrolyte dissociates into positive and negative ions. The movement of ions towards oppositely charged electrodes produces an electric current. Join two batteries to the circuit you have just made. Ask: Does the bulb glow brighter? Why? Explain the meaning of voltage as a push given to the electrons moving in a wire. By adding two batteries the push becomes stronger and the bulb glows brighter. Explain that the electric supply to our houses is of a much higher voltage.
UNIT 12Current electricity
117 1
Ask: Why mustn’t we touch live wires? Explain that high voltage can give an electric shock which can be fatal. Show the students an electric bulb. What is inside the bulb? Is the bulb empty from inside? Explain the structure of a bulb. Ask: Why does a bulb become hot when it glows? Explain that a thin wire resists the flow of the current. It becomes hot and gives off heat and light.
Summarize the lesson.
Answer to Activities4. No
No
The current increases.
Yes, bubbles of gas are seen collecting on the plates.
Water is a covalent compound and it does not ionize under the influence of an electric current.
Answers to Exercises in Unit 121. (a) Electrons that can move from one place to another are called free electrons. When free
electrons are forced to move in one particular direction, an electric current is produced.
(b) Materials through which electrons can flow easily are called conductors. They can carry an electric current. The electrons are not tightly held, so they can pass from atom to atom causing the flow of current. Materials through which electrons cannot flow easily are called insulators. The electrons are held tightly so they cannot flow through them. Insulators can be charged by rubbing because the electrons gained or lost remain on the material. They cannot pass back through it. Plastic, rubber, and wood, etc. are examples of insulators.
(c) The flow of charge in a circuit is called a current. A current is measured in amperes. The instrument that is used to measure current is called an ammeter.
(d) A switch is a small device which is used to open or close a circuit.
(e) A fuse protects electric gadgets from damage by a large current. It is made of a thin fuse wire which has a low melting point. If a large current flows through it, the fuse wire melts and breaks the circuit.
(f) A voltaic cell is a chemical cell. It consists of zinc and copper plates called electrodes, which are dipped in an electrolyte such as dilute sulphuric acid. When the electrodes are connected by a copper wire, an electric current begins to flow in the circuit.
(g) Refer to page 116 of the Pupil’s Book.
(h) When an electric current flows through a wire in a magnetic field, a force is produced. This force makes the wire move, and is called the motor effect. The motor effect is used to build electric motors. When a loop of wire carrying a current is placed between the two poles of a magnet, upward and downward forces acting on the wire make the loop turn. This twisting effect is used in electric
Amazing Science TG 7
1181
2. (b)
3. (a) parallel circuit (b) series circuit
4. (b)
5. (c)
6 Refer to Pupil’s Book.
7. (a) free electrons (b) coal
(c) conductors (d) switch
(e) low melting point (f) insulators
(g) battery (h) electrons cannot flow through them
(i) electric current (j) silicon
8. 3A, 3A, 3A
Additional Exercise
MCQs
(a) Electrons that can move from one place to another are called .
positive electrons negative electrons free electrons [free electrons]
(b) A non-metal which can conduct electricity is .
copper gold coal [coal](c) Materials which allow electricity to pass through them are called .
insulators conductors semiconductors [conductors]
(d) A device to open and close a circuit is called a .
switch fuse circuit [switch]
(e) A fuse wire has a .
low melting point high melting point [low melting point](f) Materials which allow electricity to pass through them when hot are called .
conductors semiconductors insulators [semi-conductors]
(g) A simple circuit needs a source of electricity such as a .
fuse bulb battery [battery]
(h) Insulators can be charged by rubbing because .
electrons can flow through them electrons cannot flow through them
[electrons cannot flow through them]
(i) When electrons are forced to move in a particular direction, they produce .
a conductor an insulator an electric current [an electric current](j) Which one of the following materials is a semiconductor?
carbon silicon plastic [silicon]
Unit 12 Current electricity
119 1
Uni
t: 1
2
Topi
c: C
urre
nt
elec
tric
ity
Teac
hing
obj
ecti
ves
Lea
rnin
g ou
tcom
es
Stud
ents
sho
uld
be a
ble
to:
Res
ourc
es/M
ater
ials
Act
ivit
ies/
CW
/HW
1.
Cur
rent
ele
ctri
city
•
to d
efin
e el
ectr
icity
•to
def
ine
elec
tric
cu
rren
t
•to
exp
lain
co
nduc
tors
, se
mic
ondu
ctor
s, a
nd
insu
lato
rs
•ex
plai
n w
hat e
lect
rici
ty is
•de
fine
elec
tric
cur
rent
•ex
plai
n w
hat c
ondu
ctor
s,
sem
icon
duct
ors,
and
in
sula
tors
are
Dia
gram
s of
ele
ctri
c sy
mbo
ls,
copp
er w
ires
, a
bulb
, a d
ry c
ell,
sam
ples
of c
ondu
ctor
s,
sem
icon
duct
ors
and
insu
lato
rs
Rea
ding
: p 1
11, 1
12
Act
ivity
: 1
CW
: Q7
HW
: Q1
(a)
(b)
Key
wor
ds: e
lect
rica
l ene
rgy,
ele
ctri
c cu
rren
t, co
nduc
tor,
sem
icon
duct
or, i
nsul
ator
Met
hod:
Ask
: Wha
t is
elec
tric
ity?
Exp
lain
that
ele
ctri
cal e
nerg
y is
com
mon
ly k
now
n as
ele
ctri
city
. It i
s a
flow
of e
lect
rica
lly
char
ged
part
icle
s al
ong
a co
nduc
tor.
It c
an b
e st
ored
in b
atte
ries
and
ene
rgy
cells
.
Ask
: Wha
t is
an e
lect
ric
curr
ent?
Exp
lain
that
an
elec
tric
cur
rent
is a
flow
of f
ree
elec
tron
s. F
ree
elec
tron
s ar
e el
ectr
ons
that
can
mov
e fr
om o
ne p
lace
to a
noth
er. W
hen
free
ele
ctro
ns a
re fo
rced
to m
ove
in o
ne p
artic
ular
dire
ctio
n an
ele
ctri
c cu
rren
t is
prod
uced
.
Ask
: Wha
t are
con
duct
ors?
How
do
cond
ucto
rs a
llow
ele
ctro
ns to
flow
thro
ugh
them
? E
xpla
in th
at c
ondu
ctor
s ar
e m
ater
ials
th
roug
h w
hich
ele
ctro
ns c
an fl
ow e
asily
, so
they
can
car
ry a
n el
ectr
ic c
urre
nt e
asily
. Con
duct
ors
have
ele
ctro
ns w
hich
are
not
tig
htly
hel
d so
they
can
pas
s fr
om a
tom
to a
tom
and
cau
se a
flow
of c
urre
nt. C
ondu
ctor
s th
emse
lves
do
not g
et c
harg
ed b
ecau
se
the
elec
tron
s do
not
rem
ain
on th
em. T
hey
flow
thro
ugh
them
.
Ask
: Wha
t are
sem
icon
duct
ors?
Exp
lain
that
sem
icon
duct
ors
are
mat
eria
ls th
at o
nly
allo
w e
lect
rici
ty to
pas
s th
roug
h th
em u
nder
ce
rtai
n co
nditi
ons.
For
exam
ple
the
elem
ent s
ilico
n al
low
s el
ectr
ons
to fl
ow th
roug
h on
ly w
hen
it is
hea
ted.
Ask
: Wha
t are
insu
lato
rs?
Exp
lain
that
insu
lato
rs a
re m
ater
ials
that
do
not a
llow
an
elec
tric
cur
rent
to p
ass
thro
ugh.
The
ele
ctro
ns
in in
sula
tors
are
so
tight
ly a
ttac
hed
to th
e at
om th
at th
ey c
anno
t pas
s fr
om o
ne a
tom
to a
noth
er, t
here
fore
the
elec
tron
s do
not
flo
w th
roug
h th
em. I
nsul
ator
s ca
n be
cha
rged
by
rubb
ing
them
bec
ause
whe
n el
ectr
ons
are
gain
ed o
r lo
st b
y ru
bbin
g th
ey r
emai
n on
the
mat
eria
l. E
xam
ples
of i
nsul
ator
s ar
e pl
astic
, rub
ber,
woo
d.
Dat
e:
Tim
e: 4
0 m
ins
Les
son
plan
1201
Uni
t: 1
2
Topi
c: C
urre
nt
elec
tric
ity
Teac
hing
obj
ecti
ves
Lea
rnin
g ou
tcom
es
Stud
ents
sho
uld
be a
ble
to:
Res
ourc
es/M
ater
ials
Act
ivit
ies/
CW
/HW
2.
Cir
cuits
•
to d
escr
ibe
a ci
rcui
t
•to
exp
lain
how
ci
rcui
ts a
re c
onne
cted
•to
des
crib
e a
switc
h an
d a
fuse
•to
exp
lain
how
cu
rren
t is
mea
sure
d
•de
fine
a ci
rcui
t
•de
scri
be h
ow s
erie
s an
d pa
ralle
l cir
cuits
are
co
nnec
ted
•ex
plai
n th
e fu
nctio
ns o
f a
switc
h an
d a
fuse
•ex
plai
n ho
w a
cur
rent
is
mea
sure
d
Dia
gram
s of
a s
impl
e ci
rcui
t, a
seri
es
circ
uit,
a pa
ralle
l ci
rcui
t, pi
ctur
es o
f a
switc
h an
d a
fuse
, an
amm
eter
Rea
ding
: p 1
12, 1
13
CW
: Q1
(c)
(d)
(e),
Q7
HW
: Q2,
Q3,
Q8
Key
wor
ds: c
ircu
it, s
erie
s, p
aral
lel,
ampe
re, a
mm
eter
, sw
itch,
fuse
Met
hod:
Mak
e a
sim
ple
circ
uit a
nd e
xpla
in h
ow it
wor
ks. E
xpla
in th
at a
cur
rent
is m
easu
red
in a
mpe
res.
Att
ach
an a
mm
eter
to
the
circ
uit a
nd s
how
the
read
ing
in a
mpe
res
whe
n th
e cu
rren
t is
flow
ing
thro
ugh
the
circ
uit.
Dra
w a
cir
cuit
in s
erie
s an
d a
circ
uit
in p
aral
lel o
n th
e bo
ard.
Ask
: In
whi
ch c
ircu
it do
es th
e bu
lb g
low
mor
e br
ight
ly?
Exp
lain
the
arra
ngem
ent o
f bul
bs in
bot
h ci
rcui
ts a
nd d
iscu
ss th
e di
stri
butio
n of
the
curr
ent i
n bo
th c
ases
.
Ask
: Wha
t is
a sw
itch
used
for?
Exp
lain
the
use
of a
sw
itch
in a
cir
cuit.
Ask
: Wha
t hap
pens
whe
n a
bulb
sud
denl
y go
es o
ff w
hen
we
switc
h it
on?
Exp
lain
that
we
say
that
it h
as fu
sed.
It m
eans
that
too
muc
h cu
rren
t flo
wed
into
the
bulb
and
its
filam
ent w
ire
mel
ted.
Ask
: Hav
e yo
u se
en th
e fu
se b
ox in
you
r ho
use?
Exp
lain
that
a fu
se is
a th
in p
iece
of w
ire
plac
ed in
an
elec
tric
cir
cuit.
It m
elts
w
hen
a la
rge
curr
ent f
low
s th
roug
h th
e ci
rcui
t. In
this
way
it b
reak
s th
e ci
rcui
t and
the
curr
ent s
tops
flow
ing.
A fu
se h
elps
to s
ave
our
hous
ehol
d ap
plia
nces
from
dam
age.
Ask
: How
can
we
judg
e th
e si
ze o
f a c
urre
nt fl
owin
g th
ough
a c
ircu
it? E
xpla
in th
at w
e ca
n ju
dge
the
size
of t
he c
urre
nt b
y lo
okin
g at
the
brig
htne
ss o
f the
bul
b. I
n sc
ienc
e, w
e us
e a
mea
suri
ng in
stru
men
t cal
led
an a
mm
eter
whi
ch m
easu
res
the
size
of t
he c
urre
nt
in a
mpe
res
(A).
Exp
lain
that
an
ampe
re m
eans
abo
ut 6
mill
ion,
mill
ion,
mill
ion
elec
tron
s ar
e flo
win
g ro
und
the
circ
uit i
n on
e se
cond
. The
siz
e of
the
curr
ent s
how
s ho
w m
uch
char
ge fl
ows
thro
ugh
the
circ
uit i
n on
e se
cond
. A c
harg
e is
mea
sure
d in
uni
ts
calle
d co
ulom
bs (
C).
Dat
e:
Tim
e: 4
0 m
ins
Les
son
plan
121 1
Uni
t: 1
2
Topi
c: C
urre
nt
elec
tric
ity
Teac
hing
obj
ecti
ves
Lea
rnin
g ou
tcom
es
Stud
ents
sho
uld
be a
ble
to:
Res
ourc
es/M
ater
ials
Act
ivit
ies/
CW
/HW
3.
Volta
ge
•to
def
ine
volta
ge
•to
des
crib
e ho
w
volta
ge is
mea
sure
d
•de
fine
volta
ge a
nd
to e
xpla
in h
ow it
is
mea
sure
d
•id
entif
y th
e un
its fo
r m
easu
ring
vol
tage
Dia
gram
s of
vol
tage
s ar
ound
a c
ircu
it,
conn
ectin
g a
voltm
eter
, a
batt
ery
cell
Rea
ding
: p 1
14
CW
: Ans
wer
the
follo
win
g qu
estio
ns:
a.
Wha
t is
volta
ge?
b.
How
can
vol
tage
be
mea
sure
d?
c.
Whe
re in
a c
ircu
it is
a
voltm
eter
att
ache
d?
d.
Dra
w a
dia
gram
to
show
that
the
volta
ge
acro
ss th
e bu
lbs
adds
up
to th
e vo
ltage
of
the
batt
ery.
Key
wor
ds: v
olta
ge, v
oltm
eter
, bat
tery
Met
hod:
Sho
w th
e st
uden
ts a
bat
tery
cel
l. A
sk th
em to
rea
d th
e vo
ltage
on
it. A
sk: W
hat d
oes
volts
mea
n?
Exp
lain
that
all
elec
tric
al c
ircu
its n
eed
a so
urce
of e
nerg
y. D
raw
an
elec
tric
cir
cuit
with
a b
ulb.
Exp
lain
that
whe
n th
e el
ectr
ons
are
push
ed o
ut o
f the
bat
tery
, the
y ca
rry
ener
gy w
ith th
em. T
his
ener
gy is
cha
nged
into
hea
t and
ligh
t. W
hen
the
elec
tron
s re
ach
the
batt
ery
agai
n, a
ll th
eir
ener
gy is
use
d up
. The
ele
ctri
cal p
ush
whi
ch is
nee
ded
to p
ush
a cu
rren
t to
flow
in a
cir
cuit
is c
alle
d vo
ltage
. Vol
tage
can
be
mea
sure
d by
a v
oltm
eter
. Sho
w th
e st
uden
ts a
vol
tmet
er. A
ttac
h th
e vo
ltmet
er to
a s
impl
e el
ectr
ic c
ircu
it w
ith a
bul
b, a
nd s
how
the
stud
ents
the
read
ing
on th
e vo
ltmet
er. E
xpla
in th
at a
vol
tmet
er is
att
ache
d in
a c
ircu
it in
par
alle
l to
the
com
pone
nt w
hose
vol
tage
nee
ds to
be
mea
sure
d.
Dis
cuss
the
use
of v
olta
ge to
mak
e cu
rren
t flo
w. L
arge
r vo
ltage
s ca
use
larg
er c
urre
nts.
Dat
e:
Tim
e: 4
0 m
ins
Les
son
plan
1221
Uni
t: 1
2
Topi
c: C
urre
nt
elec
tric
ity
Teac
hing
obj
ecti
ves
Lea
rnin
g ou
tcom
es
Stud
ents
sho
uld
be a
ble
to:
Res
ourc
es/M
ater
ials
Act
ivit
ies/
CW
/HW
4. R
esis
tanc
e •
to e
xpla
in r
esis
tanc
e
•to
iden
tify
the
fact
ors
on w
hich
res
ista
nce
depe
nds
•to
des
crib
e ho
w
resi
stan
ce is
m
easu
red
•de
fine
resi
stan
ce
•id
entif
y th
e fa
ctor
s on
w
hich
res
ista
nce
depe
nds
•ex
plai
n ho
w r
esis
tanc
e is
m
easu
red
Dia
gram
s of
cir
cuits
co
ntai
ning
res
ista
nce
wir
es
Rea
ding
: p 1
15
Act
ivity
: 2
CW
: W
hat a
re th
e fa
ctor
s on
whi
ch
the
resi
stan
ce o
f a
wir
e de
pend
s?
Ex:
p 1
15
Key
wor
ds: r
esis
tanc
e, n
ichr
ome
wir
e, c
oppe
r w
ire,
ohm
, om
ega
Met
hod:
Ask
: Wha
t is
resi
stan
ce? T
hrou
gh w
hich
mat
eria
ls c
an a
n el
ectr
ic c
urre
nt p
ass
easi
ly?
Exp
lain
that
cop
per
wir
e al
low
s a
curr
ent t
o pa
ss m
ore
easi
ly th
an a
nic
hrom
e w
ire.
We
say
that
the
nich
rom
e w
ire
has
mor
e re
sist
ance
. Whe
n an
ele
ctri
c cu
rren
t pa
sses
thro
ugh
a ni
chro
me
wir
e, it
bec
omes
hot
. The
rea
son
for
this
is th
at m
ore
ener
gy is
nee
ded
to fo
rce
the
elec
tron
s to
pas
s th
roug
h it
and
the
wir
e be
com
es h
ot. E
xpla
in th
at th
e re
sist
ance
of a
ny w
ire
depe
nds
on th
ree
thin
gs: t
he le
ngth
, the
dia
met
er,
and
the
mat
eria
l of t
he w
ire.
Exp
lain
the
fact
ors
on w
hich
the
resi
stan
ce o
f a w
ire
depe
nds.
Set u
p a
circ
uit w
ith a
res
ista
nce
wir
e an
d an
am
met
er. E
xpla
in th
at th
e re
sist
ance
of a
cir
cuit
tells
us
how
man
y vo
lts a
re n
eede
d to
mak
e a
curr
ent o
f 1 a
mpe
re fl
ow. I
f a c
ircu
it ha
s a
larg
er r
esis
tanc
e w
e ha
ve to
app
ly a
hig
h vo
ltage
to g
et th
e cu
rren
t of 1
A to
flo
w th
roug
h it.
A lo
w r
esis
tanc
e ne
eds
a sm
alle
r vo
ltage
.
Ask
: How
is r
esis
tanc
e m
easu
red?
Exp
lain
that
res
ista
nce
is m
easu
red
in u
nits
cal
led
ohm
s. T
o ca
lcul
ate
the
resi
stan
ce o
f a w
ire
we
can
use
the
form
ula:
vol
tage
div
ided
by
the
curr
ent i
s equ
al to
resis
tanc
e.
Dat
e:
Tim
e: 4
0 m
ins
Les
son
plan
123 1
Uni
t: 1
2
Topi
c: C
urre
nt
elec
tric
ity
Teac
hing
obj
ecti
ves
Lea
rnin
g ou
tcom
es
Stud
ents
sho
uld
be a
ble
to:
Res
ourc
es/M
ater
ials
Act
ivit
ies/
CW
/HW
5.
Sour
ces
of a
n el
ectr
ic c
harg
e:
cells
and
ba
tter
ies
E
lect
rici
ty fo
r ou
r ho
mes
Sa
fety
rul
es fo
r us
ing
elec
tric
ity
•de
scri
be th
e di
ffere
nt ty
pes
of
cells
and
bat
teri
es
•to
exp
lain
whe
re
elec
tric
ity fo
r ou
r ho
mes
and
offi
ces
com
es fr
om
•to
exp
lain
the
safe
ty
rule
s w
hen
usin
g el
ectr
icity
•ex
plai
n ho
w c
ells
and
ba
tter
ies
are
sour
ces
of
elec
tric
cha
rge
•ex
plai
n ho
w e
lect
rici
ty
com
es fr
om a
pow
er
stat
ion
to o
ur h
omes
and
of
fices
•ex
plai
n th
e sa
fety
rul
es
whe
n us
ing
elec
tric
ity
Volta
ic c
ell,
dry
cell,
ba
tter
y, m
ercu
ry b
utto
n ce
ll, r
echa
rgea
ble
cell
Pic
ture
of a
pow
er
stat
ion
A c
hart
of s
afet
y ru
les
whe
n us
ing
elec
tric
ity
Rea
ding
: p 1
15, 1
16, 1
17
Act
ivity
: 4
CW
: Q1
(g)
HW
: Q1
(f)
Key
wor
ds: v
olta
ic c
ell,
dry
cell,
bat
tery
, mer
cury
but
ton
cell,
rec
harg
eabl
e ce
ll, li
thiu
m c
ell,
pow
er s
tatio
n
Met
hod:
With
the
help
of r
eal c
ells
, dia
gram
s, a
nd c
hart
s, d
iscu
ss th
e st
ruct
ure
and
use
of v
ario
us ty
pes
of c
ells
and
bat
teri
es.
Ask
: How
do
we
use
elec
tric
ity? W
here
doe
s el
ectr
icity
for
our
hom
es a
nd o
ffice
s co
me
from
? D
iscu
ss h
ow e
lect
rici
ty is
gen
erat
ed
in a
pow
er s
tatio
n an
d br
ough
t to
our
hom
es. E
xpla
in h
ow th
e w
irin
g is
fitt
ed w
ith fu
ses
in th
e m
ain
switc
h bo
ard
to p
rote
ct o
ur
appl
ianc
es.
Exp
lain
the
safe
ty r
ules
for
usin
g el
ectr
icity
.
Dat
e:
Tim
e: 4
0 m
ins
Les
son
plan
1241
Uni
t: 1
2
Topi
c: C
urre
nt
elec
tric
ity
Teac
hing
obj
ecti
ves
Lea
rnin
g ou
tcom
es
Stud
ents
sho
uld
be a
ble
to:
Res
ourc
es/M
ater
ials
Act
ivit
ies/
CW
/HW
6.
Ele
ctri
c cu
rren
ts
and
mag
netis
m•
to d
efin
e el
ectr
omag
netis
m
•to
dis
cuss
the
uses
of
ele
ctro
mag
nets
•ex
plai
n el
ectr
omag
netis
m
•de
scri
be a
n el
ectr
omag
net
•ex
plai
n ho
w a
n el
ectr
ic
mot
or w
orks
•ex
plai
n ho
w
elec
trom
agne
ts a
re u
sed
A s
olen
oid,
ele
ctri
c m
otor
, el
ectr
ic b
ell,
diag
ram
s of
el
ectr
omag
nets
, ele
ctri
c m
otor
, ele
ctri
c be
ll
Rea
ding
: p 1
18, 1
19
Act
ivity
: 3
CW
: Q4,
Q5
HW
: Q1
(h),
Q6
Key
wor
ds: e
lect
ric
curr
ent,
elec
trom
agne
tism
, sol
enoi
d, e
lect
ric
mot
or, m
otor
effe
ct, e
lect
ric
bell
Met
hod:
Win
d a
loop
of w
ire
roun
d a
nail.
Rem
ove
the
nail
and
atta
ch th
e en
ds o
f the
coi
l to
a ba
tter
y ce
ll. B
ring
a m
agne
tic
need
le c
lose
to th
e co
il. T
he n
eedl
e w
ill b
e de
flect
ed s
how
ing
that
ther
e is
a m
agne
tic fi
eld
arou
nd th
e co
il. E
xpla
in th
at th
is ty
pe
of a
coi
l is
calle
d an
ele
ctro
mag
net o
r so
leno
id. I
f the
num
ber
of tu
rns
of th
e co
il is
incr
ease
d, th
e el
ectr
omag
net c
an b
e m
ade
stro
nger
.
Ask
: Wha
t is
an e
lect
ric
mot
or?
How
doe
s an
ele
ctri
c m
otor
wor
k? E
xpla
in th
at w
hen
an e
lect
ric
curr
ent f
low
s in
a w
ire
in a
m
agne
tic fi
eld,
a fo
rce
is p
rodu
ced
whi
ch m
akes
the
wir
e m
ove.
Thi
s fo
rce
is c
alle
d th
e m
otor
effe
ct. T
he m
otor
effe
ct is
use
d by
sc
ient
ists
and
eng
inee
rs to
bui
ld e
lect
ric
mot
ors.
Show
the
stud
ents
a m
odel
of a
n el
ectr
ic b
ell.
Exp
lain
its
part
s. A
ttac
h th
e w
ires
to a
bat
tery
. Sw
itch
on th
e cu
rren
t. E
xpla
in th
e w
orki
ng o
f the
bel
l and
the
role
of t
he e
lect
rom
agne
t ins
ide
it.
Dat
e:
Tim
e: 4
0 m
ins
Les
son
plan
125 1
Unit 12: Current electricity Worksheet 1
Name: Date:
1. Draw the symbols for the following electrical components:
a. connecting wire
b. cell
c. battery
d. voltmeter
e. ammeter
f. two wires joined
g. light bulb
h. switch
2. Draw the following:
a series circuit a parallel circuit
Photocopiable material
1261
Unit 12: Current electricity Worksheet 2
Name: Date:
Q. Write the type of cell next to its description.
Description Type of cell
1. A chemical cell with zinc and copper plates dipped in an electrolyte such as dilute sulphuric acid
2. An electrical cell having a metal zinc case and a carbon rod in the middle; the electrolyte is a paste of zinc chloride and ammonium chloride
3. An electrical cell made up of a number of cells joined together; the electrodes are lead plates dipped in an electrolyte such as dilute sulphuric acid
4. A very small cell which produces a large current for a short time or a small current for a long time; it is very expensive
5. A cell made up of nickel and cadmium; it is completely sealed and can produce a large current; it is very expensive.
6. A very small and light cell made of lithium; it lasts a long time and is very expensive.
Photocopiable material
127 1
Teaching objectives:• to explain the scientific theories regarding the origin of the universe• to discuss the characteristics of a star• to describe the different heavenly bodies• to describe galaxies• to explain the major constellations visible in the night sky• to explain the scientific theories about the birth and death of our Sun• to describe a ‘black hole’
Teaching strategy:Historical background
The study of stars and planets has always been important to human beings. In the Stone Age, before calendars were developed, the movement of stars was used to plan the sowing time for crops. Five thousand years ago, priests in the Middle East were making astronomical measurements. They could predict eclipses, and used their information for ceremonies and for astrology. In the 1700s, astronomers collected accurate information on the position of stars and planets so that ocean navigation could become much safer. Nowadays, astronomers continue to try and learn about the nature of the universe. Attempts to explore space has given us new knowledge, and have led to the development of new materials. As you travel in a space ship from the Solar System to the outer edge of the Milky Way Galaxy the planets become invisible, but you can still see the Sun. The Sun is one of many stars grouped together in one of the spiral arms of our galaxy. On a dark night you may already have seen the stars in this spiral arm as a misty area across the sky, known as the Milky Way. You will have to travel much further before you can see what the whole galaxy looks like. Our galaxy contains about 100,000 million stars. It is spiral in shape. It has a central core of older stars, and the spiral arms contain newer stars. Take the students to a planetarium.
Ask: How do you think the universe came into being? Discuss the theories about how the universe was formed. Ask: What is the Sun? Why is the Sun hot? Are stars hot? Explain what stars are and how they are formed. Discuss the life of a star. Discuss other heavenly bodies in space. Show the students pictures of a telescope. Draw a diagram on the board to explain the structure and working of a telescope. Discuss the safety measures that need to be taken to view the sun and other objects in space.
Summarize the lesson.
Investigating space
UNIT 13
1281
Answers to Exercises in Unit 131. (a) Space is emptiness. It is black because it has no light of its own. It is neither hot nor cold and
there is no air or water in space. But there are billions and billions of stars, huge clouds of dust and gas, and meteorites and rocks hurtling through space. Waves of light from stars travel through it and tiny invisible particles move about in it.
(b) Space is full of waves. These are waves of radiation. Radiation is streams of tiny, tiny bits of atoms travelling at tremendous speed. Radiation is given off by most things in space–stars, quasars, planets, and nebulae.
(c) Radiation comes to the Earth in the form of heat, light, radio waves, X-rays, cosmic rays, and gamma rays. The Earth’s atmosphere shuts out some of these things; otherwise they could be very harmful for all living things on Earth.
(d) The big bang theory suggests that the universe began about 10, 000 million years ago with an enormous explosion. Scientists believe that all the matter now in the universe was contained in one primitive atom which they called a primordial atom. This atom blew up and its contents flew off in all directions. As the primordial material spread out, it cooled, joined together and made the galaxies.
This theory, however, does not suggest where the primordial atom came from in the first place.
(e) The pulsating universe theory suggests that the universe is continually contracting and expanding. When the universe has expanded to a certain size it will begin to shrink. The galaxies will be pushed closer and closer together. Eventually they will explode causing the universe to expand again.
The expanding universe theory suggests that the universe will never collapse. It will keep on expanding. This theory implies that there has only ever been one ‘big bang’.
[Ask the students opinion about what they think how the universe was formed]
(f) A huge mass of stars is called a galaxy. There are at least ten billion other galaxies, and possibly many more than this! And each of them contains many billions of stars!
Galaxies shaped like the Milky Way galaxy are called spiral galaxies. Some galaxies are round or oval. They are called elliptical galaxies. Others have no regular shape.
Most galaxies are so far away that we cannot see them without a telescope, but we can see a few. People north of the Equator can see the Andromeda Galaxy, which is the farthest object that we can see with our eyes alone. People south of the Equator can see two galaxies as white patches in the sky. They are the Small and Large Magellanic Clouds.
(g) On a clear summer night we can sometimes see a bright haze in a part of the sky. This haze is called the Milky Way. It looks like a gigantic cloud of stars, close together. The Milky Way is part of an even bigger cloud of stars. This star cloud is shaped like a disc with a bulge in the centre. This huge mass of stars is called a galaxy - the Milky Way Galaxy. Our Sun is one of the stars in this galaxy. The Sun is so far from the centre that it takes the Sun 200 million years to go all the way round it.
2. All stars are balls of hot, glowing gas, like our Sun. But stars can be very different from one another. A star such as our Sun is a medium-sized star. Stars called giant stars may be a hundred times bigger than our Sun. Stars called super giants may be a thousand times bigger. The smallest stars are called dwarf stars. Some of them are smaller than our Earth. The colour of a star shows
Unit 13 Investigating space
129 1
how hot it is. The hottest stars shine with brilliant blue light. White stars are less hot. Yellow stars, such as our Sun, are cooler, and the red stars are the coolest of all.
Great clouds of gas and dust called nebulae are found throughout the universe. Stars may form in nebulae. The process begins when gravity pulls the gas and dust particles together. As the mass of particles becomes tightly packed, or compressed, it heats up. In time, the temperature inside rises to over one million degrees Celsius. At such high temperatures atoms of hydrogen gas begin to fuse together to form helium gas. As they do so, they release enormous amounts of energy as heat and light. The mass of gas and dust begins to shine as a star.
3. (a) Great clouds of gas and dust called nebulae, are found throughout the universe. Stars may form in nebulae. The process begins when gravity pulls the gas and dust particles together. As the mass of particles becomes tightly packed, or compressed, it heats up. In time, the temperature inside rises to over one million degrees Celsius. At such high temperatures atoms of hydrogen gas begin to fuse together to form helium gas. As they do so, they release enormous amounts of energy as heat and light. The mass of gas and dust begins to shine as a star.
(b) Pulsars were once giant stars, but now they have shrunk until they are much smaller than the Earth. There is as much material in a pulsar as there is in our Sun, but the material is tightly squeezed together. Pulsars give off energy as ordinary stars do, but they do not give it in a steady stream. They give off even bursts of energy, like a beating heart.
Quasars seem to be like huge, dim stars, far out in space. They are not really dim. They are the brightest things in space. They give off as much light as millions and millions of stars all rolled into one. Perhaps they seem dim because they are so far away.
(c) Red giant stars and white dwarf stars are stars that have grown old. When a yellow star, such as our Sun, gets old and ready to die, it swells up and becomes a red giant star. Then it shrinks and becomes a white dwarf. A white dwarf is a very heavy star. It swells into a super giant. It uses up the last of its energy and blasts itself apart in a supernova explosion. After a supernova, a tiny neutron star (smaller than our planet) may be left.
4. Astronomers think that a black hole could be an enormous star that has shrunk until it is squeezed together so tightly that nothing is left of it but gravity. The pull of gravity would be so strong that nothing could get away from it, not even light. That is why they are called black holes.
5. Moons, planets, comets, and asteroids do not emit light. They reflect light.
Black holes absorb everything, including light.
6. Stars are the only heavenly bodies that emit light. They use nuclear fusion which produces enormous amounts of energy in the form of heat and light.
The Sun is the only object in the Solar System that generates and emits visible light.
7. Refer to page 129 in the Pupil’s Book.
Amazing Science TG 7
1301
Additional Exercise
MCQs
(a) Space and all the things in it make up the .
world solar system universe [universe]
(b) The big bang theory suggests that the universe was contained in a primitive atom called .
nuclear atom primordial atom electronic atom [primordial atom]
(c) are balls of hot glowing gases.
Stars Comets Meteors [Stars]
(d) Bright stars which join up to make patterns in the sky are called .
galaxies constellations nebulae [constellations]
(e) A huge mass of stars which may be spiral or elliptical is called .
great bear pole star galaxy [galaxy]
(f) Giant stars which have shrunk, but give off bursts of energy are called .
constellations pulsars quasars [pulsars]
(g) are great clouds of gases and dust in space.
Nebulae Comets Pulsars [Nebulae]
(h) Stars may have formed in .
nebulae solar system clouds [nebulae]
(i) Stars that have grown old are called .
white dwarfs black holes quasars [white dwarfs]
(j) Our is a star that is part of the Milky Way Galaxy.
Moon Sun Earth [Sun]
Unit 13 Investigating space
131 1
Uni
t: 1
3
Topi
c: I
nves
tiga
ting
sp
ace
Teac
hing
obj
ecti
ves
Lea
rnin
g ou
tcom
es
Stud
ents
sho
uld
be a
ble
to:
Res
ourc
es/M
ater
ials
Act
ivit
ies/
CW
/HW
1.
Wha
t is
spac
e?
H
ow th
e un
iver
se
was
form
ed
St
ars,
co
nste
llatio
ns,
gala
xies
•to
def
ine
spac
e
•to
exp
lain
the
scie
ntifi
c th
eori
es
put f
orw
ard
to
expl
ain
the
orig
in
of th
e un
iver
se
•to
def
ine
star
s,
cons
tella
tions
, an
d ga
laxi
es
•de
fine
spac
e
•di
scus
s th
eori
es th
at tr
y to
exp
lain
the
orig
in o
f th
e un
iver
se
•ex
plai
n w
hat s
tars
, co
nste
llatio
ns, a
nd
gala
xies
are
Dia
gram
s an
d ch
arts
ex
plai
ning
spa
ce a
nd
the
theo
ries
of h
ow th
e un
iver
se w
as fo
rmed
,pi
ctur
es o
f sta
rs,
cons
tella
tions
, an
d ga
laxi
es
Rea
ding
: p 1
25, 1
26, 1
27
CW
: Q1
(a)
(b)
(c)
HW
: Q1
(d)
(e)
(f)
(g)
Key
wor
ds: s
pace
, wav
e, u
nive
rse,
rad
iatio
n, p
rim
ordi
al a
tom
, big
ban
g th
eory
, pul
satin
g un
iver
se th
eory
, exp
andi
ng u
nive
rse
theo
ry
Met
hod:
Exp
lain
the
hist
oric
al b
ackg
roun
d of
how
the
univ
erse
cam
e in
to b
eing
.T
he s
tudy
of s
tars
and
pla
nets
has
alw
ays
been
impo
rtan
t to
hum
an b
eing
s. In
the
Ston
e A
ge, b
efor
e ca
lend
ars
wer
e de
velo
ped,
the
mov
emen
t of s
tars
was
use
d to
det
erm
ine
the
sow
ing
time
for
crop
s. F
ive
thou
sand
yea
rs a
go, p
ries
ts in
the
Mid
dle
Eas
t wer
e m
akin
g as
tron
omic
al m
easu
rem
ents
. The
y co
uld
pred
ict e
clip
ses,
and
used
thei
r in
form
atio
n fo
r re
ligio
us c
erem
onie
s an
d fo
r as
trol
ogy.
In th
e 17
00s,
ast
rono
mer
s co
llect
ed a
ccur
ate
info
rmat
ion
abou
t the
pos
ition
of s
tars
and
pla
nets
so
that
oce
an n
avig
atio
n be
cam
e m
uch
safe
r. N
owad
ays,
ast
rono
mer
s co
ntin
ue to
dis
cove
r m
ore
abou
t the
nat
ure
of th
e un
iver
se. A
ttem
pts
to e
xplo
re s
pace
hav
e gi
ven
us n
ew k
now
ledg
e, a
nd h
ave
led
to th
e de
velo
pmen
t of n
ew m
ater
ials
.If
you
cou
ld tr
avel
in a
spa
cesh
ip fr
om th
e So
lar
Syst
em to
the
oute
r ed
ge o
f the
Milk
y Way
Gal
axy,
the
plan
ets
wou
ld b
ecom
e in
visi
ble,
but
you
cou
ld s
till s
ee th
e Su
n. T
he S
un is
one
of m
any
star
s gr
oupe
d to
geth
er in
one
of t
he s
pira
l arm
s of
our
gal
axy.
O
n a
dark
nig
ht, y
ou m
ay h
ave
seen
the
star
s in
this
spi
ral a
rm a
s a
mis
ty a
rea
acro
ss th
e sk
y, k
now
n as
the
Milk
y W
ay. Y
ou w
ould
ha
ve to
trav
el m
uch
furt
her
befo
re y
ou c
ould
see
wha
t the
who
le g
alax
y lo
oks
like.
Our
gal
axy
cont
ains
abo
ut 1
00,0
00 m
illio
n st
ars.
It is
spi
ral i
n sh
ape
and
has
a ce
ntra
l cor
e of
old
er s
tars
. The
spi
ral a
rms
cont
ain
new
er s
tars
.If
pos
sibl
e, ta
ke th
e st
uden
ts to
a p
lane
tari
um to
obs
erve
the
univ
erse
and
sta
rs.
Ask
: How
do
you
thin
k th
e un
iver
se c
ame
into
bei
ng?
Dis
cuss
the
theo
ries
abo
ut h
ow th
e un
iver
se w
as fo
rmed
.A
sk: W
hat i
s th
e Su
n? W
hy is
the
Sun
hot?
Exp
lain
wha
t sta
rs a
re a
nd h
ow th
ey a
re fo
rmed
. Dis
cuss
con
stel
latio
ns a
nd g
alax
ies.
Dat
e:
Tim
e: 4
0 m
ins
Les
son
plan
1321
Uni
t: 1
3
Topi
c: I
nves
tiga
ting
sp
ace
Teac
hing
obj
ecti
ves
Lea
rnin
g ou
tcom
es
Stud
ents
sho
uld
be a
ble
to:
Res
ourc
es/M
ater
ials
Act
ivit
ies/
CW
/HW
2.
Stra
nge
thin
gs in
sp
ace
T
he te
lesc
ope
•to
des
crib
e so
me
stra
nge
thin
gs in
sp
ace
•to
des
crib
e th
e lif
e of
a
star
•to
exp
lain
how
a
tele
scop
e w
orks
•to
exp
lain
the
safe
ty
prec
autio
ns to
be
take
n w
hen
look
ing
at th
e Su
n
•de
scri
be p
ulsa
rs, q
uasa
rs,
and
blac
k ho
les
•ex
plai
n ho
w lo
ng a
sta
r la
sts
•ex
plai
n th
e w
orki
ng a
nd u
se
of a
tele
scop
e
•de
scri
be th
e ha
rmfu
l ef
fect
s of
look
ing
dire
ctly
at
the
Sun
and
to li
st th
e pr
ecau
tions
that
mus
t be
take
n
Pic
ture
s of
pul
sars
, qu
asar
s, s
tars
Rea
ding
: p 1
27, 1
28
CW
: Q
2, Q
3, Q
4
HW
: Q
5, Q
6, Q
7
Pro
ject
: p 1
31
Key
wor
ds: p
ulsa
r, qu
asar
, bla
ck h
ole,
neb
ula,
hel
ium
gas
, red
gia
nt, w
hite
dw
arf
Met
hod:
Sho
w th
e st
uden
ts p
ictu
res
of p
ulsa
rs a
nd q
uasa
rs.
Exp
lain
wha
t pul
sars
and
qua
sars
are
and
how
they
are
form
ed. E
xpla
in w
hat a
bla
ck h
ole
is. D
escr
ibe
the
life
of a
sta
r. E
xpla
in
that
whi
te d
war
fs a
nd r
ed g
iant
s ar
e st
ars
that
hav
e gr
own
old.
Des
crib
e th
e pr
oces
s by
whi
ch a
sta
r be
com
es a
red
gia
nt a
nd th
en
how
a w
hite
dw
arf s
wel
ls to
form
a s
uper
gia
nt a
nd b
last
s its
elf a
part
in a
sup
erno
va e
xplo
sion
, and
fina
lly a
tiny
neu
tron
sta
r m
ay
be le
ft. D
iscu
ss th
e em
issi
on a
nd r
efle
ctio
n of
ligh
t by
heav
enly
bod
ies.
Exp
lain
that
bla
ck h
oles
abs
orb
ever
ythi
ng in
clud
ing
light
.
Show
the
stud
ents
a m
odel
of a
tele
scop
e. E
xpla
in it
s st
ruct
ure
and
its u
se. D
raw
a d
iagr
am o
n th
e bo
ard
to e
xpla
in h
ow a
n up
side
dow
n im
age
of a
hea
venl
y bo
dy is
form
ed.
Exp
lain
the
safe
ty p
reca
utio
ns to
be
take
n w
hen
view
ing
the
Sun.
Dat
e:
Tim
e: 4
0 m
ins
Les
son
plan
133 1
Unit 13: Investigating space Worksheet 1
Name: Date:
1. Fill in the blanks in the text to explain how the universe was formed.
Scientists suggest various ______________________ to explain how the universe was formed:
(i) The Big Bang theory suggests that the universe began about ______________________
years ago, with an enormous ______________________. Scientists believe that all the
matter that is now contained in the universe was contained in one primitive atom called
the ______________________.
This atom blew up and its contents flew off in all ______________________. As the
material spread out, it cooled, joined together, and formed the ______________________.
(ii) The ______________________ theory suggests that the universe is continually
contracting and expanding. When the universe has ______________________ to a certain
size it will begin to ______________________. The ______________________ will be
pushed closer and closer together. Eventually they will ______________________, causing
the universe to ______________________ again.
(iii) The ______________________ theory suggests that the universe will never collapse. It will
continue to ______________________. This theory implies that there has only ever been
one ______________________.
Photocopiable material
1341
Unit 13: Investigating space Worksheet 2
Name: Date:
Q. Write the name of the heavenly bodies described below.
Description Name
1. A ball of hot, glowing gases
2. A star a hundred times bigger than our Sun
3. A star a thousand times bigger than our Sun
4. The smallest star
5. Patterns of stars in the sky
6. A cloud of stars
7. Shrunken stars that give out bursts of energy
8. The brightest stars in space
9. An enormous star that has shrunk until it is squeezed so tightly that nothing is left of it except gravity
10. A yellow star that swells up and becomes red when it gets old and is ready to die
Photocopiable material
135 1
Test paper 3Time: 3 hours Total marks: 100
1. Attempt any six questions. [All questions carry equal marks.] [60]
(a) What is heat? Explain the methods of heat transfer?
(b) How do convection currents move in a liquid? Explain what causes land and sea breezes.
(c) Explain how heat is radiated. How does the temperature of a liquid in a thermos flask remain the same for a long time?
(d) What is temperature? What does the temperature of a body depend on?
How is temperature measured? Name the various types of thermometers.
(e) (i) What is refraction of light? What is meant by the refractive index of a material?
(ii) Calculate the speed of light in water when the refractive index of water is 1.33.
(f) (i) Define an oscillation, a period, frequency of an oscillation?
(ii) A child on a swing goes backwards and forwards 100 times in five minutes. Calculate the period of the oscillation and the frequency in hertz.
(g) What is the motor effect? How is the motor effect used in electric motors?
(h) (i) Briefly explain the Big-bang theory.
(ii) Compare the expanding universe theory with the pulsating universe theory for the origin of the universe. Which theory do you think could be most accurate? Why?
(i) What is a star? What do scientists think about how stars are formed?
2. Draw and label the following diagrams: [15]
(a) A dry cell
(b) An electric bell and its circuit
(c) A telescope
3. Correct the following statements. [10]
(a) When an object is heated, its molecules lose energy.
(b) Rubber and wood are good conductors of electricity.
(c) The ability to conduct heat is called radioactivity.
(d) Water is a good conductor of heat.
(e) The flow of heat through a liquid is called radiation.
(f) Monsoon winds are conduction current winds.
(g) During the daytime, water heats up more quickly than land.
(h) Radiation needs a medium to travel through.
Test paper 3
1361
(i) When a substance is cold, its molecules move quickly.
(j) Absolute zero is equal to –273°F.
4. Write short notes on the following: [15]
(a) nebulae
(b) pulsars
(c) quasars
(d) red giants and white dwarfs?
(e) black holes
Test paper 3