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4541 CHEMISTRY MODUL P3T (TAHAP 2)

CHAPTER 4 : THE PERIODIC TABLE OF ELEMENTS

A Historical Development Of The Periodic Table

1 Antoine Lavoiser(1743-1794) The first Scientist classifies substances including . and ., into

..and.

Substances were classified into fourgroups with similar chemical properties.

His classification was unsuccessful because , and a few

other compounds were also considered as elements.

2 Johann Dobereiner(1780-1849) Divided the elements into groups of three elements with similar chemical

properties, known as .

The atomic mass of the middle element was approximately the average atomic massof the other two elements in each triad.

This classification led chemist to realise that there was a relationship between the

. and the atomic mass of each element.

Example :

Element in triad Li Na KAverage relativeatomic mass of Li

and K

Relative atomicmass, Ar

7 39 2

397 += 23

3 John Newlands (1837-1898) He arranged the known elements in order ofincreasing atomic mass.

Elements with similar chemical properties were repeated at every eighth element.

This was known as the Law of.

This system was inaccurate because the Law of Octaves was obeyed by the first 17elements only and there were some elements with wrong atomic mass/mass number.

JPNT 2009 CHAPTER 4: PERIODIC TABLE OF ELEMENTS

38

?


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However, Newlands was the first chemist to show the existence of.for the properties of elements.

4 Lothar Meyer(1830-1895) He plotted a graph of.. against for all theknown elements.

Atomic volume =

He realised that elements with .. occupied equivalentpositions along the curve.

He was successful in showing that the properties of the elements formed a periodic

pattern against their..

5 Dimitri Mendeleev (1834-1907) Arranged the elements in order of ...

He grouped the elements according to ...

[Elements with similar chemical properties were in the same group].

He left gaps in the table to be filled by .. elements.

He was able to predict the properties of undiscovered elements.

[e.g: Ekasilicon, Es is predicted by Mendeleev in 1869 was discovered asGermanium, Ge in 1886 ].


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Mass of 1 mol (g)

Density (g cm-3)

Li

Atomic

volume

Atomic mass

Na

K

Be

Mg

Ca

B

Al

What colourshould be here?


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6

Hendry J. G. Moseley (1887-1915)

Studied the .. of elements.

[Introduced the concepts ofproton numberof each elements]

He concluded that should be used as the basis for theperiodic changes of chemical properties of elements instead of the atomic mass.

He rearranged the elements in order ofincreasing proton numberin the PeriodicTable.

B Arrangement of Elements in the Periodic Table

Elements in the Periodic Table are arranged in an .. order of

.., ranging from 1 to 112.

Elements with .. are placed in the same vertical column called

..

Lanthanides

Actinides

There are vertical columns of elements in the Periodic Table.

Each vertical column of elements is called a ..

The vertical columns are known as to .

There are horizontal rows of elements in the Periodic Table.

Each of these horizontal rows of elements is called a

The horizontal rows are known as . to.


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Horizontal row

Verticalcolumn


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Activity1:-

In the table below, write :

(a) Group 1 to 18(b) Period number 1 to 7

(c) the symbol of each element from Hydrogen to Calcium

H He

Lanthanides

Actinides

The number ofvalence electrons in an atom decides the .. of anelement in the Periodic Table.

Example :

The proton number of sodium, Na is 11.The electron arrangement of sodium atom is 2.8.1The valence electron of sodium is 1Sodium is placed in Group 1 in a Periodic Table.

For elements with 1 and 2 valence electrons, the group numberof the element is thenumber of valence electrons in its atom.

For elements with 3 to 8 valence electrons, the group numberof the element is the

number of valence electrons in its atom plus ten (+10) [ valence electron + 10 ]

Example :

The proton number of chlorine is 17The electron arrangement of chlorine is 2.8.7The valence electrons of chlorine is 7Chlorine is placed in Group 17 [ 7 +10 ]


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Elements from Period 3

Complete the following table.

The position in theperiodof an

element in the

Periodic Table is

determined by the

number of

..

occupied/filled with

electrons in the atom

of that element.

Theperiod numberof an element is the number of shell occupied with electrons in itsatom.

Example :

The proton number of magnesium is 12The electron arrangement of magnesium is 2.8.2There are 3 shells occupied with electrons in magnesium atom.Theperiodnumber of magnesium in the Period Table is 3

Activity2:-Complete the following table :

Element Li C O Ne Mg Al P Cl K Ca

Proton number 3 6 8 10 12 13 15 17 19 20Electronarrangement

2.1 2.8.2 2.8.3

Number ofvalenceelectron

3

Group 13

Number ofshellsoccupied with

electrons

3


ElementProtonnumber

Electronarrangement

Valenceelectron

Group

Na 11 2.8.1 1 1

Mg 12

Al 13 2.8.3 3 13

Si 14

P 15S 16

Cl 17 2.8.7 7 17

Ar 18

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Group :

Valence electrons + 10


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Period 3

Specific name of certain groups :

Group Specific name

1 Alkali metal #

2 Alkali-earth metal

3 to 12 Transition element #

17 Halogen #

18 Noble gas #

# The important groups that will be studied from the aspect ofphysicaland chemicalproperties.

Activity3:-

1 Write the electron arrangement for each element in the following Periodic Table.

Symbol of element : [ Standard form ]

GROUP

1 18

1H1

.

2 13 14 15 16 17

4 He2

7 Li3

...

9Be4

..

11 B5

12 C6

14 N7

16 O8

19F

9

20 Ne10

23 Na11

..

24 Mg12

.. 3 4 5 6 7 8 910

11

12

27 Al13

28 Si14

31 P15

32 S16

35 Cl17

40 Ar18

39 K19..

40 Ca20..

TRANSITION ELEMENTS


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A

XZ

.number

..number1

2

3

4

PERIOD


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2 Complete the statement and answer the following questions based on the table below.

ElementNucleonnumber Number of neutrons

A 9 4

B 31 16

C 35 18

(i) The proton number of A is and the number of electrons in an atom A is

. .

The electron arrangement of atom A is..

The valence electron of atom A is ..

Atom A is in Group ..and Period ..

(ii) Atom B is in Group ..and Period ..

(iii) A student states that atom C is in Group 17 and Period 3 in Periodic Table of

Element. Is the statement true or false? Explain your answer.

.........

.

.

Advantages of Grouping Elements in the Periodic TableThe systematic arrangement of elements in the Periodic Table helps us to study the

elements systematically, especially in their and .. properties.

Elements with the .. number of . are placed in the same

Group because they have the same chemical properties.Elements are arranged systematically in the Periodic Table in the order ofincreasingproton numberwhich enable chemists to study, understand and remember :

(a) the chemical and physical properties of all the elements and compounds in an orderlymanner.

(b) the properties of elements and their compounds are predicted based on the position ofelements in the Periodic Table.

(c) the relationship between the elements from different groups can be known.


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C GROUP 18 ELEMENTS [Refer to Text Book, page 64]

1. Group 18 elements consists of ., .., .., ,

. and ..

2. These elements are known as gases.

3. Group 18 elements exist as monoatomic at room condition because Noble gases

achived stable electron arrangement which is for helium and

for other elements.

4. Noble gases do not have to lose, gainorshare electrons.

Physical Properties of Group 18 Elements

Noble gases have very .. atomic sizes.

They are . gases at room temperature and pressure.

Noble gases have .. melting and boiling points and also .. densities.

Noble gases are in water, conduct electricity and

. conductors of heat.

Going down Group 18 [Refer to Text Book, page 64]

Element

Relative

atomicmass

Protonnumber

Atomic

radius(nm)

Melting

point(oC)

Boiling

point(oC)

Density(g dm-3)

Helium, He 4 2

Neon, Ne 20 10

Argon, Ar 40 18

Krypton, Kr 84 36

Xenon, Xe 131 54

Radon, Rn 222 86

When going down Group 18 :

The atomic size as the number of shells in the atom increases from Helium

to Radon.

The melting and boiling points is very low.

because the atoms of Noble gases are attracted by weak force.

Less energy is required to overcome it.

However, the melting and boiling points . when going down Group 18.

because the atomic size of each element down the group,


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Increase

s

Increase

s

Increase

s


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the forces of. between the atoms of each element become stronger

thus more is required to the stronger forces of ..

. during melting or boiling.

The density of an element .. down the group because the atomic mass

of each element is

The Inert Property of Group 18 Elements

All Noble gases are inert which means .. .

Noble gases and the electron arrangement of their atoms.

Noble gas Electron arrangement

Helium 2

Neon 2.8Argon 2.8.8

Krypton 2.8.18.8

Xenon 2.8.18.18.8

Radon 2.8.18.32.18.8

Helium has two valence electrons. This is called a . electron arrangement.

Other Noble gases have eight valence electron called the .. electron arrangement.

These electron arrangements are very stable.

That is why Noble gases exist as monoatomicgases and are chemically unreactive;

because they achived the stable octet/duplet electron arrangement.

Uses of Group 18 Elements

Noble gas Uses

Helium, He

Neon, Ne

Argon, Ar

Krypton, Kr

Xenon, Xe

Radon, Rn


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D GROUP 1 ELEMENTS

1. Write the name and symbols of elements in Group 1 (exceptHydrogen)

2. Group 1 are also known as which react with water to form alkalinesolutions.

3. Write the symbols in the boxes for all the elements in Group 1 in the Periodic Table ofElements :

4. Write the proton number and electron arrangement for all elements in Group 1.

ElementsProtonnumber

Electronarrangement

Density /g cm-3

Boilingpoint /

0

CLi 3 0.534 1360

Na 0.971 900

K 0.862 777

Rb 2.8.18.8.1 1.530 505

Cs 2.8.18.18.8.1 1.973

Fr 2.8.18.32.18.8.1

All Group 1 elements have valence electron in their outermost occupiedshells.

5. Physical Properties of Group 1 elements :

metals.

densities.

melting points.

silvery solid with . surface.

good of heat and electricity.


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compared to other metals

such as iron and copper.


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Change in the physical properties going down the group :

The atomic size because the number of shells increases.

The density because the increasing in atomic mass is fasterthan the increasing in atomic volume/size.

The melting and boiling points because when the atomic sizeincreases, the metal bond between the metal atoms becomes weaker.

The hardness of the metal .

6. Chemical Properties of Group 1 elements :

(a) React with waterto produce alkaline metal hydroxide solutions [colourless

solutions] and released gas.

Metal* Observation

Li

Lithium moves .. on water surface with sound.

The solution formed; turns ..litmus paper to...

Na

Sodium moves . on water surface with sound.

The .. solution formed; turns .litmus paper to..

K

Potassium moves . on water surface with .sound.

The . solution formed; turns .litmus paper to..


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water

metal*

Redlitmus paper

turnsblueRedlitmus paper

Reactionbecomes

morevigorous

React

ivityin

creases

Metal G1 + H2O metal hydroxide + Hydrogen gas


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Chemical equation :

# Chemical equation

2Li + 2H2O 2LiOH + H2

Lithium Water Lithium Hydrogen gashydroxide

Write the chemical equation for the sodium and potassium.

..

(b) React with oxygen gas to produce metal oxides [white solids].

Metal* Observations

Li

Lithium burns with a flame.

A . / fume solid is produced.

Na

Sodium burns . with a .. flame.

A .. solid is produced.

K Potassium burns . with a flame.


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Gas jar

Metal*

Oxygen gas

White fume

Gas jar spoon

Reactionbec

omes

morevigorous

Metal G1 + O2 metal oxide


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A solid is produced.

Chemical equation :

Example:

+ O2 2Na2O

4K + O2

(c) React with chlorine gas to produce metal . [white solids].

Elements Observations

Li

Lithium burns with a .. flame.

A . solid is produced.

Na

Sodium burns .. with a flame.A . solid is produced.

K

Potassium burns ... with a ...flame.A solid is produced.


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Gas jar

Metal*

Chlorine gas

White fume

Gas jar spoon

Metal G1 + Cl2 metal chloride

4Li + O2

2Li2O

Lithium Oksigen gas Lithium Oxide


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Group 1 elements also react with bromine gas to form metal bromides.

Complete the chemical equation following.

2Li + Br2 2LiBr

Na + Br2 ..

K + Br2 ..

7. Reactivity of elements in Group 1 :

When going down Group 1,

the proton number are ..

the number of shells occupied with electrons are

the atomic size of atoms are

the single valence electron becomes away from the nucleus.

the force of attraction between the nucleus and valence electron (nuclei attraction)

becomes

it is for the atom to donate the single valence

electron to achieve the stable octet/duplet electron arrangement of the atom

of Noble gases.

Reactivity increases when going down the group!


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Alkali metals have one valence electron in their outermost occupied shells.Each of them reacts by donating one electron from its outermost occupiedshell to form an ion with a charge of +1, thus achieving the stable electron

arrangement of the atom of noble gas.

Example :

Na Na+ + e K K+ + e2.8.1 2.8 2.8.8.1 2.8.8


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Activity4 :-

1. Table below shows the electron arrangements of element W, X and Y.Arrange the elements in ascendingorder of reactivity.

Element Proton Number ElectronArrangement

W 11 2.8.1

X 3 2.1

Y 19 2.8.8.1

Answer: .

[ Size of atom increases when the number of shells filled with electrons increases]Safety precautions in handling Group 1 elements

Alkali metals are very reactive. Safety precautions must be taken when handling alkalimetals.

The elements must be stored in paraffin oil in bottles Do not hold alkali metals with your bare hands Use forceps to take them Wear safety goggles

Wear safety gloves Use a small piece of alkali metal when conducting experiments


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X

a

W

b


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E GROUP 17 ELEMENTS

1. Write the symbol of elements in Group 17.

Fluorine Chlorine Bromine Iodine Astatine

2. Group 17 elements are known as ..

3. Halogens exist as diatomic molecules.{ F2, Cl2, Br2, I2 }

4. Halogens have .. valence electrons.

5. All Group 17 elements are non-metals.

6. Write the symbol in the boxes for all the element in Group 17 in thePeriodic Table of Elements :

17

7. Write the proton number and electron arrangement :

Elements Proton number Electron

arrangement

F

Cl

Br 35 2.8.18.7

I 53 2.8.18.18.7

At 85 2.8.18.32.18.7


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F Cl Br I At

Proton number : ....

Number of protons :

Number of electrons :

Number of shells occupied with

electrons : ...

Atomic size :

Molecular size : ..

Going down the group :


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8. Physical properties of elements in Group 17 :

(i) Complete the table below :

ElementSymbo

lProtonNumber

ElectronArrangemen

t

Meltingpoint /

oC

Boiling

point /oC

Physicalstate atroomTemp.

Colour

Flourine 9 -220 -188

Chlorine 17 -101 -34

Bromine 35 2.8.18.7 -7 59

Iodine 53 2.8.18.18.7 114 184

(ii) Physical state of halogens at room temperature, 25 oC :

Fluorine and chlorine are ............... , bromine is a ..................... and iodine isa ...............

(iii) The colour of the elements becomes .. going down the group.

(iv) Halogen have melting and boiling points because their molecules

are attracted to each other by . inter-molecular forces. (Van der Waals

force : force of attraction between molecules).

(v) When going down the group, the melting and boiling points increases /decreases.This is because :

the molecular size ..

Forces of attraction between molecules becomes

Need . energy to overcome the forces of attraction betweenmolecules.

the melting and boiling points ..

9. Chemical Properties

(a) React with waterto produce two acids.

Example :


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Chlorine

gas

water

In general :

Br2 + H2O HBr + HOBr

Halogen : F, Cl, Br, I


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Cl2 + H2O +

Chlorine gas Hydrochloric acidHypochlorus acid

Br2 + H2O +

I2 + H2O +

(b) React with hot iron/ferum to produce iron(III) halides.

Example :


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HX and HOX solutions are ...

HOX solution exhibits property.

Hydrobromic acid Hypobromus acid

Hydroiodic acid Hypoiodus acid

Potassium

manganate(VII)

Iron wool

Heat

Concentratedhydrochloric acid

Combustion tube

Soda lime

To absorb excess

Cl2

gas that is

poisonous so that

it does not escape

to the enviroment.

To produce Cl2

gas

Bromine

water

water

Heat

Iodine

(solid)

water

Heat


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2Fe + 3Cl2 2FeCl3

Iron(III) chloride

Fe + Br2

Iron(III) .....................

Fe + I2

Iron(III) .....................

(c) Halogen reacts with sodium hydroxide, NaOH solution to produce

, .. and water.

Example :

2KOH + Cl2 KCl + KOCl + H2O

Potassium Sodiumchloride chlorate(I)

KOH + Br2 + + H2O

Potassium Potassiumbromide bromate(I)


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Chlorine

gas

Sodium hydroxide

solution

Solid

iodine

Heat

Iron

wool

Heat

Alkali


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LiOH + I2 + + H2O

Chemical properties of all elements are . because the number ofvalence electrons are the same and attain/achive the Noble gas arrangement in asimilar way.

10. Reactivity of Group 17 elements :

When going down Group 17,

the proton number are

the number of shells occupied with electrons are

the atomic size of atoms are

the outermost occupied shell of each halogen atoms becomes

away from the nucleus.

the nuclei attraction forces to attract one electron into the outermost occupied

shell by the nucleus becomes

it is for the atom to attract one electron to achieve stableoctet/duplet electron arrangement of the atom of Noble gas.


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Halogens have seven valence electrons in their outermost occupied shells.Each of them reacts by receiving one electron in its outermost occupied shell to forman ion with a charge of -1, orby sharinga pairofelectrons thus achieving the stableelectron arrangement of the atom of noble gas.

Example :

F + e F- Cl + e Cl-

2.7 2.8 2.8.7 2.8.8

Complete the electron arrangement for the atoms and molecule of flourine below :

two fluorine atoms Fluorinemolecule ( F

2)

Exists as diatomicmolecules [ 2 atoms of elements sharinga pairof its valenceelectron ] to achive the stable octet electron arrangement.

F F F F


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The strength of halogen atom to attract electron decrease from Fluorine to

Astatine [Electronegativity decreases]

this causes the reactivity down the group.

Activity 5 :-

1

Chlorine, bromine and iodine have . number ofvalence electrons.

When halogens take part in chemical reactions, their atom always gain

. electron to achieve . electron arrangement / a

stable electron arrangement.

2

The explanation

The atomic size . down the group.

The distance of the outermost shell becomes from the nucleus.

The force of attraction of the nucleus on the electrons of the outermost shell

..

The tendency of an atom to receive .. electron to achieve an octet

electron arrangement .

3

The explanation

The atomicsize of flourine is . than chlorine.

The between nucleus of fluorine atom and valence

electrons are .

Fluorine atom can electron easily.


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Chlorine, bromine and iodine have similar chemical properties.

Do you know WHY???

The reactivity of halogens decrease down the group.

Do you know WHY???

Why fluorine atom forms a negative ion more easily

than chlorine?


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Safety precautions in handling Group 17 elements

1. The vapour of flourine, chlorine and bromine are

2. The following precaution should be taken when handling halogen :

a) Halogen gas and liquid should be handled inside a

b) Wear safety when handling halogen fumes.

c) Wear safety when handling halogen materials.

Activity 6 :-

1. Elements X, Y and Z are in the same group in the Periodic Table of Elements.

Element X Y Z

Proton number 9 17 35

(a) What is the valence electron of the elements X, Y and Z?

(b) Which group in the periodic table can you find the elements X, Y and Z?

(c) Element Y can react with water.State two chemical properties of the solution produced?

(d) Write an equation for the reaction between element Z and hot iron.

2. (a) List all halogen elements from the top to the bottom of Group 17.

.

(b) Which are the most reactive and least reactive halogen?


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Most reactive : , least reactive : .............

3. Write the chemical equations for the following reaction :

(a) Chlorine with water : ...

(b) bromine with iron : ...

(c) iodine with sodium hydroxide : ...

4. Explain the changes to the reactivityof halogens when going down Group 17.

The atomic size of halogen .. down the group.

The distance of the outermost shell becomes from the

nucleus.

Therefore, the force of attraction by the nucleus on the electrons in the

outermost shell becomes

The tendency of an atom to . one electron to achieve an

octet electron arrangement decrease.

This causes the reactivity down the group.

5. Explain the changes to the electronegativityof halogens when going down Group17.

The atomic size of halogen .. down the group.

The distance of the outermost shell becomes from thenucleus.

Therefore, the force of attraction by the nucleus on the electrons in the

outermost shell becomes

The tendency of an atom to . one electron to achieve an

octet electron arrangement decrease.

This causes the electronegativity down the group.


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F ELEMENTS IN A PERIOD

Properties of elements in Period 3

Complete the table below.

Element of Period 3 Na Mg Al Si P S Cl Ar

Proton number 11 12 13 14 15 16 17 18

Electronarrangement

2.8.1 2.8.8

Valence electron[ Group ]

1[ 1 ] [ ] [ ] [ ] [ ] [ ] [ ]

[ ]

Atomic size

Physical state atroom temperature

solid

Electronegativity

Electropositivity

The trends of changes acrossPeriod 3 (from leftto right)

1. The proton numberincreases by unit from one element tothe next element.

2. All the atoms of the elements have shells occupied/filledwith electrons.

3. The number ofvalence electrons in each atom increases from to..

4. The atomic radius/size of atom of the elements ..

This is due to increasing of nuclei attraction force on the electrons.


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5. The electronegativity of elements

This is also due to the ..of the nuclei attraction force on the

in the outermost shell and the in atomic size.

6. All the elements in Period 3 exist as .. except chlorine andargon which are

ACID-BASE properties of oxides ofelements in Period 3.

Na2O MgO Al2O3 SiO2 P4O10 SO2 Cl2O7

(oxides) .. oxide (. oxides)

Basic oxides reacts with acids to form . and ..

Example :

Na2O + 2HNO3 2NaNO3 + H2O

Acidic oxides reacts with alkalis to form . and ..

Example :

SO2 + 2NaOH Na2SO3 + H2O

Amphotericoxides can react with both acids and alkalis.

Na & Mg are ., Al is ., Si, P, S & Cl are .

The elements change from metals to metalloid and finally to non-metals across theperiod.

Uses of semi-metals (metalloids) in Industry

Semi-metals or metalloids are weakconductors of electricity. Semi-metals such assilicon and germanium are used as semiconductors.

Semiconductors are used to make diodes and transistors that widely used in themaking of microchips for the manufacture of electrical and microelectronicequipments such as computers, mobile phones, televisions, digital cameras andvideo recorders.


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SEMI-METALSe.g: silicon and germanium

used to make

. and .

widely used in the making of ..

for the manufacture of :

Activity 7 :-

1 Table below shows the symbol of element, proton number and atomic radius ofelements in Period 3.

Element Na Mg Al Si P S Cl Ar

Proton number 11 12 13 14 15 16 17 18

Atomic radius 0.156 0.136 0.125 0.117 0.111 0.104 0.099 -

Electronarrangement

(a)Complete the electron arrangement in the above table.

(b)When crossing the period from left to right, the atomic size decreases. Explain why.


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..and ..


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(c) Write the symbol of elements for metal, metalloid and non-metal.

Metal Metalloid Non-metal

1. .2. .

3. .

1. 1..

2. 3. 4.

(d) Table below shows the symbol of oxide compound when the elements in period 3 arereacted with oxygen.

Na2O MgO Al2O3 P4O10 SO2

Classify the oxides into basic oxide, acidic oxide and amphoteric oxide.

Basic oxide Acidic oxide Amphotericoxide

G TRANSITION ELEMENTS

1. Elements from Group . to Group . in the Periodic Table.

[ Between Group . to Group .]

2. All transition elements are ., thus, these elements have thefollowing properties :

solids with surfaces.

ductile

malleable

high tensile strength


64

. melting and boiling points

.. densities

good .. of heat andelectricit


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3. Special Characteristics / Superior Properties ofTransition Elements

(i) ..(ii) (iii) .

Different Oxidation Numbers

Transition elements can form ions with different oxidation numbers when formingcompounds.

TransitionElement

OxidationNumber

Name of ion Ionicsymbol

Example of compoundFormula Name

Iron, Fe+2 Iron(II) ion Fe2+ FeCl2 Iron(II) chloride

+3 Fe3+ Iron(III) chloride

Copper, Cu+1 Copper(I) ion Cu2O

+2 Cu2+ Copper(II) oxide

Nickel, Ni+2 Ni(NO3)2

+3 Ni3+ Ni(NO3)3

Coloured Ions orCompounds

The colours of some aqueous solutions of ions of transition elements :

Name of Ionof transition element

Formula of Ionof transition element

Colourin aqueous solution

Chromate ion

Dichromate ion

Manganate(VII) ion

Iron(II) ion

Iron(III) ion

Copper(II) ion

Cobalt(II) ion

Manganese(II) ion

Chromium(III) ion

Nickel(II) ion

Examples of someprecious stones and the transition elements present which givetheir distinctive colours :

Precious Colour Transition Element


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Stone present

Ruby Red

Sapphire Blue

Emerald Green

Amethyst Purple

Act as Catalysts

Transition elements or its compounds can act as catalysts in certain reactions.Catalysts are chemicals which can increase the rate of a reaction.

Example :

Industrial Process ProductTransition element used

as catalyst

Haber Process

Contact Process

Ostwald Process

Activity 8 :-

1 Figure 1 below shows part of the Periodic Table of Elements.

H He

O

Mg Al

FIGURE 1

Based on Figure 1 above, answer the following questions :

(a) What is the element represented by the symbol Fe?

(b) In figure above, mark X in the boxes for all the transition element.

(c) State one specific characteristic of transition element.


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Fe


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(d) Write the electron arrangement for the Mg atom

(e) Write the chemical equation for the reaction between aluminium and oxygen

gas.

(f) Based on the above informations, which gas is more suitable to be used inmeteorological balloons?Give one reason.

2 Table 2 shows the proton numbers of element P, Q, R, S and T.

Element Proton number Electron arrangement

P 3

Q 6

R 9

S 11

T 17

TABLE 2

(a) Complete the electron arrangement for all elements above.

(b) In which Group is element S located in the Periodic Table of Elements?

......

(b) State two elements in Table 2 that shows the same chemicalproperties.Explain the answer.

...


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Helium Gas

light

notreactive

Hydrogen Gas

light

flammable colourless

.


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.

(c) (i) Between elements P and S, which one is more reactive?Explain your answer.

..

..

..

..

..

(d) Arrange the elements P, Q, R, S and T in order ofincreasing of atomic size.

END OF CHAPTER 4

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c4 tahap 2 noraidah

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