SMK DATUK MANSOR, BAHAU, NEGERI SEMBILAN

NAME : ..

CLASS : ..
Chapter 2: The Structure of Atom

CHAPTER 2: THE STRUCTURE OF ATOM

A MATTER
Learning Outcomes
You should be able to:
describe the particulate nature of matter,
state the kinetic theory of matter,
define atoms, molecules and ions,
relate the change in the state of matter to the change in heat,
relate the change in heat to the change in kinetic energy of particles,
explain the inter-conversion of the states of matter in terms of kinetic theory of
matter.

Activity 1

Fill in the blanks with suitable word(s) in the box given

Ions tiny molecules discrete smallest

take part positively-charged in released
atoms gas chemically solid absorbed
different arrangement movement liquid neutral

1. Matter is made up of . and particles.

2. The tiny particles may be atoms .. or .
3. An atom is the . particle of an element that can
in a chemical reaction. Example : , ,..
4. A molecule is a group of two or more which are
bonded together. Example : , ,..
5. An ion is a . or negatively charged particle. Example :
, ,..
6. Diffusion occurs when particles of a substance move between the particles
of another substance.
7. Diffusion of matter occurs most rapidly in state, slower in
.. state and slowest in .. state. This is due to the
different and . of particles in the three states of
matter.
8. Matter consists of small particles that always collide among each other. The particles
move faster when energy is and the particles move slower when the
energy is ....

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Chapter 2: The Structure of Atom

Activity 2

1. Complete the table below.

State of matter Solid Liquid Gas

Draw the
arrangement of
particles

The particles are The particles are The particles are

Arrangement of packed .. . but not .. apart
particles together in an in .... from each other.
..
manner

Particles can only Particles can Particles can

Movement of . and .., . .,
particles .. about and and
their fixed positions . freely
throughout the liquid

Attractive forces Particles are Particles are attracted The attraction forces
between the attracted by very by between particles are
particles . strong forces. forces

Energy content
of particles .. .

2. Underline the correct word in the passage below.

When heat energy is supplied to particles in matter, its kinetic energy (increases
/decreases) and the particles in matter vibrate ( faster/ slower) When matter loses heat
energy, the kinetic energy of the particles (increases/decreases) and they vibrate
( faster/ slower).

3. The flow chart below shows the interconversion of the states of matter. State the change
of matter for each conversion in the spaces provided.

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Chapter 2: The Structure of Atom

A B ... C....

D. E .. F

4. (a) Choose the correct word(s) from the list given below to complete the passage below.
(solid, gas, boiling point, melting point)

The temperature at which a . completely changes to a liquid is

called ..

(b) Choose the correct word(s) from the list given below to complete the passage below.
(solid, gas, liquid, intermolecular, released, absorbed, overcome )

Boiling point is the temperature at which a changes into .. .

During the boiling process, the temperature remains constant because the heat energy is
by the particles and is used to the
forces between particles.

(c) The graph below shows the change in temperature with time when a matter in solid
state was heated.

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Chapter 2: The Structure of Atom

Temperature/ OC
D

Time/s

By referring to the graph above, complete the table below.

Explanation in terms of energy change and
Point States of matter
movement of particles

Heating causes the particles to ..

A to B more energy and vibrate .. The
temperature of the substance and the kinetic energy

Continuous heating does not cause the temperature of

the substance to increase. The energy absorbed is
B to C used to the forces of
attraction between the . The
constant temperature is called the ..
..

Continuous heating causes the temperature of the

C to D liquid to The particles move
. Because their kinetic energy is
..

5. (a) The graph below shows the change in temperature with time when a matter in liquid
state is left to cool.
Temperature / OC

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Chapter 2: The Structure of Atom

QQ R

SD

Time/s
By referring to the graph above, complete the table below.
Point State of matter Explanation

P to Q As cooling continues, particles lose ..

Kinetic energy, move . and
the temperature

Q to R The stronger bonds . during

freezing release energy. This energy released
is the same as the energy . to the
surroundings during cooling. Thus the
temperature remains unchanged. This constant
temperature is called ..

R to S The temperature . as the

cooling continues

(b) Choose the correct word(s) from the list given below to complete the passage below.
(solid, gas, liquid, exactly balanced, decreased, increased)
Freezing point is the temperature at which a changes into .
During the freezing process, the temperature remains unchanged because the heat lost
to the environment is ... by the heat released when the liquid
particles rearrange themselves to become solid.

Learning Outcomes
You should be able to:
B describe
THE the
ATOMIC STRUCTURE
development of atomic model,
state the main subatomic particles of an atom,
compare and contrast the relative mass and the relative charge of the protons, electrons and
neutrons,
define proton number,
define nucleon number,
determine the proton number,
determine the nucleon number,
relate the proton number to the nucleon number,
relate the proton number to the type of element,
write the symbol of elements,
determine the number of neutrons, protons and 6 electrons from the proton number and the
nucleon number and vice versa,
construct the atomic structure.
Chapter 2: The Structure of Atom

Activity 3
The Historical Development Of Atomic Models
1. Complete all the blanks and draw the structure of each atomic model.

Model Structure Characteristic

Daltons atomic The atom was imagined as a small
model indivisible ball similar to a very tiny
(proposed by ball.

in 1805 )

J.J Thomson discovered

Thomsons atomic the.., a negatively-
model charged particle.
(proposed by The atom was described as a
.. sphere of positive charge
In 1897) embedded with electrons.

Ernest Rutherford discovered

Rutherfords atomic ., a positively-charged
model particle in an atom.
(proposed by The central region of atom has a
very small positively-charged
in 1911) .., which
contains almost all the mass of the
atom.

Bohrs atomic The electrons in an atom move in

model .. around the nucleus
(proposed by which contains protons.
in
1913.)

Chadwick proved the existence of

Chadwicks atomic .., the neutral particle
model in the nucleus.
(proposed by The nucleus of the atom contains
... protons & neutrons, and the
in 1932) nucleus is surrounded by
electrons.

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Chapter 2: The Structure of Atom

Activity 4
Subatomic Particle Of An Atom

Fill in the blanks and complete the table.

1. Atoms are made up of subatomic particles namely protons, and ..

2. and .. are found in the nucleus of an atom while electrons

surround the nucleus.

Subatomic particle Symbol Relative mass Relative electric charge

Proton
Neutron
Electron

3. The proton number of an element is the number of in its atom.

Proton Number, Z = Number Of Proton

4. Protons and neutrons are collectively called nucleons.

The nucleon number of an element is the total number of .. and

.. in its atom.

Nucleon Number, A = Number Of Proton + Number Of Neutron

5. The nucleon number is also known as the ..

= Nucleon Number -- Proton Number

= A -- Z

6. Symbols of Elements
The standard representation for an atom of any element shows the proton number and
the nucleon number of the element. It can be written as follows:

A
Z X
# A Nucleon number
Z proton number
X symbol of element
1 21 Proton number 2
H Sc Nucleon number He
1 45 4
3 4 5 6 7 8 9 10
Li Be B C N O F Ne
7 9 11 12 14 16 19 20
11 12 13 14 15 16 17 18
Na Mg Al Si P S Cl Ar
23 24 27 28 31 32 35 40

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Chapter 2: The Structure of Atom

19 20 21
K Ca Sc
39 40 45

By referring to part of the Periodic Table of Element above, complete the table below.

Proton No. of Nucleon No. of Standard

Element Symbol
number neutrons number electrons representation
Scandium

Aluminium

Argon

Beryllium

Boron

Calcium

Carbon

Chlorine

Fluorine

Helium

Hydrogen

Lithium

Magnesium

Neon

Nitrogen

Oxygen

Phosphorus

Potassium
C ISOTOPES AND THEIR IMPORTANCE

Learning Outcomes
You should be able to:
state the meaning of isotope,
list examples of elements with isotopes,
determine the number of subatomic particles of isotopes,
justify the uses of isotope in daily life.

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Chapter 2: The Structure of Atom

Activity 5
Fill in the blanks.

1. Isotopes are atoms of the same element with the . of proton but

.. of neutron.

2. Complete the table below:

Number of Symbol of Number of Number of Number of Name of

Element
isotopes isotopes protons electrons neutrons isotope
1
1 H 1
1 Hydrogen-2
Hydrogen 3
1 2
16
8 O 8 8 Oxygen-16
8 9
Oxygen 3
18
8 O
6 Carbon-12
6 7
Carbon 3
14
6 C 6 8
35
17 Cl 17
Chlorine 2
17 20
35 Bromine-80
Bromine 2
35 35 Bromine-81

3. For each of the isotope listed below, state one of its uses.

a) Gamma rays of Cobalt-60: .

b). Carbon-14: ..

c). Phosphorus-32: ..

d). Sodium- 24:

e). Iodine -131:

D THE ELECTRONIC STRUCTURE OF AN ATOM

Learning Outcomes
You should be able to:
describe electron arrangements of elements with proton numbers 1 to 20,
draw electron arrangement of an atom in an element,
state the meaning of valence electrons,
determine the number of valence electrons from the electron arrangement of an atom.

Activity 6

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 Chapter 2: The Structure of Atom

Fill in the blanks and complete the table below.

1. Electrons are filled in specific shells, starting with the shell nearest to the nucleus of the
atom. Every shell can be filled only with a certain number of electrons.
For the elements with proton number 1 to 20:

The first shell can be filled with a maximum of . electrons

The second shell can be filled with a maximum of . electrons
The third shell can be filled with a maximum of .electrons

Use x as symbol for

electrons. Draw the
maximum number of
electrons in each shell.

2. Draw the electron

arrangement of a sodium atom,
23 Number of protons
11 Na in the box and complete
Number of electrons
the table below
Number of neutrons
Proton number
Nucleon number
Electron arrangement

x 3. Valence electrons are electrons in the .. shell of a neutral

atom.
4. Identify the number of valence electrons in these atoms according to its electron
arrangement.
Atom of Element Electron Arrangement Number of valence electrons
Oxygen 2.6
Aluminium 2.8.3
Chlorine 2.8.7
Neon 2.8
Potassium 2.8.8.1
Magnesium 2.8.2

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