introducing scienceaerodrive.ccchwc.edu.hk/~lck/science/s1/js_ansbk_u01_ee... · 2018-09-10 · 1...

1 Introducing Science

1-4Thinking

What is the difference between a discovery and an invention?

Discoveries are the observation and explanation of the natural phenomena, while inventions are creations of new

methods or devices.

1-5Activity 1.1

Great scientists

1. C 2. D 3. A 4. B

1-9Activity 1.3

The two sides of science

TimCars can take us from one place to another quickly, but

they cause air pollution in the environment.

JoanneWhen drugs are used properly, they can cure diseases.

The abuse of drugs may lead to health problems.

StevenThe internet can help people get information all over the world. However,

some people are obsessed with the internet and may fail to develop

communication / social skills.

Unit 1 Introducing Science2

1-11TEST YOURSELF 1.1

1. (a) What is science about?

Science is the study of nature .

(b) List three branches of science.

Biology, chemistry, physics, geology, astronomy (any three)

2. Complete the following statements about the discoveries or inventions made by different

scientists.

(a) Galileo Galilei invented (invented / discovered) a telescope and discovered (invented / discovered) the four moons of Jupiter.

(b) Sir Isaac Newton discovered (invented / discovered) the force of gravity.

(c) Alexander Graham Bell invented (invented / discovered) the telephone.

(d) Marie Curie discovered (invented / discovered) two radioactive elements.

1-15Activity 1.4

Where does the mould come from?Tim used a scientific method to study a daily life problem. For Steps 1 to 5 below, identify the

steps of the scientific investigation. Put your answers in the spaces provided.

1. Making observations 2. Asking a question

3. Suggesting a hypothesis 4. Testing the hypothesis

5. Drawing a conclusion

1-16Thinking

If you were Tim, how would you test the second hypothesis ‘The mould on the bread comes from

the air’?

Prepare two pieces of bread. Leave one piece exposed to the air and the other enclosed in a plastic bag. Examine

them after a few days. If the second hypothesis is correct, the bread exposed to air will be covered with mould,

while the bread not exposed to air will not be covered with mould.


1-21Activity 1.5

How does temperature affect the growth of mould on bread?Tim’s experiment:

Is this a fair test?

This is not (is / is not) a fair test.

It is because the two set-ups are different in more than one (only one / more than one) condition(s).

Steven’s experiment:


This is not (is / is not) a fair test.

It is because the two set-ups are different in more than one (only one / more than one) condition(s).

Doris’ experiment:


This is (is / is not) a fair test.

It is because the two set-ups are different in only one (only one / more than one) condition(s).


1. The scientific investigation consists of the following main steps:

Making observations ➜ Asking a question

➜ Suggesting a hypothesis ➜ Testing the hypothesis

➜ Drawing a conclusion

2. Write ‘T’ if the statement is true and ‘F’ if the statement is false in each box provided.

(a) Scientific knowledge is always true. F

(b) Science can solve all of our problems. F

(c) Scientists classify objects into groups according to their similar

features. T

(d) In a fair test, the variable to be studied should be kept constant. F


1-26Activity 1.6

Equipment in your school laboratoryLook around your school laboratory. Can you find the following equipment? Write the names of the

equipment in the spaces provided.

1. gas tap 2. sink and water tap

3. electric socket 4. first-aid box

5. fume cupboard 6. eye-wash bottle

7. fire extinguisher 8. fire blanket

9. sand bucket

1-26Thinking

What is the difference between a science laboratory and an ordinary classroom?

A science laboratory is usually bigger and with laboratory equipment.

An ordinary classroom is usually smaller and without laboratory equipment.

(Accept other reasonable answers)


1-27Activity 1.7

Equipment in your school laboratory1. Which floor is your school's science laboratory located on?

The science laboratory is located on .

2. Draw the layout of the science laboratory in the space below. Label the blackboard, benches,

doors and the laboratory equipment using the symbols given below.

(Depends on the environment of the laboratory.)

Symbols

teacher’s bench and blackboard

student’s bench

laboratory door

fire extinguisher

sand bucket

fire blanket

fume cupboard

first-aid box

3. If there is an accident, how can you leave the laboratory safely? Use red arrows ‘➞’ to mark the

escape route on the layout.


layout. 1-28Activity 1.8

Potential dangers in the laboratory

Student(s) Potential dangerReason for the

potential dangers

Donald, Ken Playing and running in the laboratory D

JamesTouching the electric plug and socket with wet hands

B

Chloe Not tying back long hair C

DoraPointing the mouth of the test tube towards others while heating

A

Emma Eating and drinking in the laboratory E

1-31Activity 1.9

Coping with laboratory accidentsWhat should you do if the following accidents occur? Link the accidents and the actions you should

take.

Accident

Action

• • • •

1. Some chemicals

are spilt on

your hand.

2. Some chemicals

get into your

eye.

3. You touch

something hot and

burn your finger.

4. You smell gas

leakage.

• • •A. close the gas tap B. wash it with an

eye-wash bottle

C. wash the affected

area with running

water


1-33EXPERIMENT 1.1

Studying the ways of putting out a fire

Part A Using water

2. What happens to the flame?

The flame goes out (remains unchanged / goes out).

Part B Using sand



Part C Using carbon dioxide



Discussion

Which component of the fire triangle is removed by

1. water? heat

2. sand? oxygen

3. carbon dioxide? oxygen

1-34Thinking

Which component of the fire triangle is removed in each of the methods shown in Fig. 1.24?

Oxygen is removed in the three methods.



Finish the following matching.

1. We usually conduct a scientific investigation in a D .

2. We should wear F while heating substances.

3. There are A on the containers of hazardous

chemicals.

4. Fire extinguisher, sand bucket and B are some

common fire-fighting equipment in the laboratory.

5. The three components of the fire triangle are fuel, C and heat.

A. hazard warning symbols

B. fire blanket

C. oxygen

D. laboratory

E. carbon dioxide

F. safety goggles

G. classroom

H. eye-wash bottle

1-41EXPERIMENT 1.2

Transferring and mixing solutions1. Note down the colour of each solution.

Solution A B C

Colour colourless clear blue colourless

5. Record your observations in the same table.

Mixed solutionColour of the mixed

solutionAny solids formed at

the bottom?Any bubbles

released?

A + B colourless no no

A + C colourless no yes

B + C pale blue yes no


1-43EXPERIMENT 1.3

Lighting a Bunsen burner4. Examine the flame of the Bunsen burner. Write down your observations in the table below:

When the air hole is closed When the air hole is open

What is the colour of the flame?

yellow blue

Is the flame regular or irregular in shape?

irregular regular

Is the flame luminous or non-luminous?

luminous non-luminous

Is the Bunsen burner quiet or noisy?

quiet noisy

1-46EXPERIMENT 1.4

Using a Bunsen burner for heating

Part B Heating a solid

1. Record the colour of the solid.

The colour of solid A before heating: blue

3. Record the colour of the solid.

The colour of solid A after heating: white



1. Link the following apparatus and their uses.

Apparatus (a) dropper (b) reagent

bottle

(c) glass rod (d) safety

goggles

(e) Bunsen

burner

• • • • •

• • • • •Use to protect

our eyes

to transfer a

small amount

of liquid

to store

liquid

to heat

substances

to stir

liquid

2. The correct order of lighting a Bunsen burner is:

D B A C E

1-51EXPERIMENT 1.5

Measuring length1.

Object Instrument Length

1. Length of the bench metre rule / half-metre rule / measuring tape

2. Length of your science textbook half-metre rule / plastic rulerAnswers vary with students. The appropriate unit is: 1. m2. cm3. cm4. cm

3. Diameter of a 50-cent coin plastic ruler

4. Circumference of a football measuring tape

2. How would you measure the thickness of a page of your science textbook using a plastic ruler?

(a) Method:

Measure the thickness of the book. Then divide it by the number of pages of the book.

(b) The thickness of a page of the book:

Thickness of a page =

thickness of the book

number of pages of the book

=

Answers vary with students. The appropriate unit is mm.


1-53EXPERIMENT 1.6

Measuring volume

Part A Measuring the volume of an object with regular shape

1. Measure and record the height, width and length of your science textbook.

height = cm

width = cm

length = cm

2. Calculate the volume of the book.

Volume of the book = × ×

= cm3

Part B Measuring the volume of liquids

2. Record the volume of each container (V1) as printed on the label in the table below.

Container Volume on the label, V1 (cm3) Volume measured, V2 (cm3)

A

B

C

4. Based on your results, is there any difference between V1 and V2?

If yes, how would you explain the difference?

The water splashed out of the container while being poured. (Accept other reasonable answers)

Part C Measuring the volume of an object with irregular shape

1. Pour water into a measuring cylinder to half full. Take the reading. Let this volume be V1.

V1 = cm3 (Answers vary with students.)

2. Tie a thread to an object with irregular shape, e.g. a piece of plasticine. Lower the plasticine

into the water. Read the new volume. Let this volume be V2.

V2 = cm3 (Answers vary with students.)

3. Calculate the volume of the piece of plasticine.

Volume of the plasticine = V2 – V1

= cm3

(Answers vary with students.)


1-56EXPERIMENT 1.7

Measuring temperature3. Measure the temperature of hot water, tap water and iced water. Record the readings in the

table below.

Air in the room

Hand Hot water Tap water Iced water

Temperature (°C)

1-58EXPERIMENT 1.8

Measuring mass1.

Item 1. A boy2. A bag of

oranges3. A can of coke

4. A ten-dollar coin

Instrument bathroom scale spring balance / electronic balance electronic balance electronic balance

Mass Answers vary with students. The appropriate unit is: 1. kg 2. g 3. g 4. g

2. How would you measure the mass of 100 cm3 of water using a measuring cylinder and an

electronic balance?

(a) Measure the mass of a dry (wet / dry) measuring cylinder (M1) using an electronic

balance. Then add 100 cm3 of water to the measuring cylinder and measure the

total mass (M2). The mass of 100 cm3 of water is equal to M2 – M1 .

(b) The mass of 100 cm3 of water:

Mass of 100 cm3 of water = M2 – M1 The appropriate unit of the mass of 100 cm3 of water is g.



1-59Thinking

Which stopwatch in Fig. 1.42 is more precise? Why?

The mechanical stopwatch can measure time intervals accurate to 0.2 s. The digital stopwatch can measure time

intervals accurate to 0.01s. The digital stopwatch is more precise than the mechanical stopwatch.

1-60EXPERIMENT 1.9

Measuring the pulse rate

Part A Measuring pulse rate with a stopwatch

1. Write down his / her resting pulse rate as Reading 1 in the table below.

Reading 1 Reading 2 Reading 3

Resting pulse rate (pulses per minute)


4. Repeat Step 3 twice to obtain two more readings.

5. Calculate the mean resting pulse rate of your classmate in number of pulses per minute.

His / her mean resting pulse rate is pulses per minute.

Part B Measuring pulse rate with a data-logger with pulse rate sensor

4. Take the reading for two minutes.

His / Her resting pulse rate is .

Discussion

What is the advantage of using a data-logger to measure pulse rate over the use of a stopwatch?

The data-logger enables accurate and continuous pulse rate monitoring.





Measurement Instrument(s)Unit(s) commonly

usedUnit symbol(s)

1. Length • plastic ruler

• metre rule

• half-metre rule

• measuring tape

• kilometre • km

• metre • m

• centimetre • cm

• millimetre • mm

2. Volume • ruler

• measuring

cylinder

• cubic metre • m3

• cubic centimetre • cm3

• litre • L

• millilitre • mL

3. Temperature • thermometer • degrees Celsius • °C

4. Mass • balance • kilogram • kg

• gram • g

5. Time • clock

• watch

• stopwatch

• hour • h

• minute • min

• second • s


1-70REVISION EXERCISE

A. Multiple-choice Questions

1. B

4. C

2. A

5. D

3. C

6. D

B. Short-answer Questions7. (a) Fill in the boxes below to show the three components of the fire triangle.

fuel

heat

oxygen

(b) Which component of the fire triangle has been removed when we use a sand bucket to put

out a fire? Circle it in the above diagram.

8. (a) Which of them is a fair test?

Experiment C (A / B / C) is a fair test.

(b) Which variables should be kept constant in the experiment? Put a ‘✓’ in the appropriate

boxes.

The size of the parachutes

✓ The height from which the

parachutes are dropped

✓ The shape of the parachutes

The time the parachutes

take to fall

(c) What conclusion can Tim obtain from the fair test?

A bigger parachute falls more slowly (faster / more slowly) than a smaller

parachute.

introducing scienceaerodrive.ccchwc.edu.hk/~lck/science/s1/js_ansbk_u01_ee... · 2018-09-10 · 1...

Documents