LOWER SECONDARY SCIENCE TEXTBOOK

7 Give an example of a living organism that is neither plant nor animal.
8 Give an example of how fungi are useful to Man.
9 The pictures below show four animals.
Construct a classif ication key to identify these animals.

shark donkey sea urchin ostrich

10 Classify these living things using the key that follows.

Orangutan Ostrich Water lily Fish Dolphin Fern

Living things

Animals Plants

Live on land Live in water Reproduce Do not reproduce
by seeds by seeds

Lay eggs Give birth Have scales Do not
have scales

50 Classif ication

Chapter Matter

3 Matter is anything that has mass and takes up space. Everything
you can see, hold, taste or smell, and even things you cannot
see, such as air, are made up of matter. Can you identify some
examples of matter in the picture below?

Firman Allah Subhanahu Wa Ta’ala
Tafsirnya:
Kemudian Dia menunjukkan
kehendakNya untuk menciptakan
langit sedang langit itu masih berupa
asap lalu Dia berfirman kepadanya
dan kepada bumi: “Kamu berdua
turutlah perintahKu sama ada
dengan sukarela atau terpaksa.”
Kedua-duanya berkata: “Kami berdua
taat menurut perintahMu.”(11)

Then He rose over (Istawâ) towards
the heaven when it was smoke, and
said to it and to the earth: “Come
both of you willingly or unwillingly.”
They both said: “We come willingly.”

(Surah Fushshilat: 11)

Let’s Explore

• What are the states of matter?
• What are the properties of each

state of matter?
• How can we distinguish between

the three states of matter?
• How does diffusion occur in the

three states of matter?
• What are elements, compounds

and mixtures?

Matter 51

3.1 Matter Around Us

You should be able to:
• recognise that everything that exists around us is matter,
• state that all matter is made up of tiny particles.

Matter is everywhere. Matter is anything that has mass and
volume. It includes trees, insects and human beings, which
are living things, as well as rocks, wood and water, which are
non-living things. There is a great variety of matter on Earth.
However, some things that exist are not matter. These include
heat and sound.
All matter is made up of tiny particles. These particles are so
small that we cannot see them with the naked eye.

3.2 States of Matter

You should be able to:
• state that matter exists as solid, liquid and gas,
• explain and compare the properties of the three states of

matter using the particulate model of matter with reference to:
i) arrangement of particles, and
ii) movement of particles;
• describe and compare properties of matter in terms of

shape and volume.

There are three states of matter — solid, liquid and gas,
and each has its own unique properties.

Matter

Solid Liquid Gas

examples examples examples
• wood
• stones • perfume • air
• most metals • water • oxygen
• oil • chlorine

Wood Stones Perfume Water Balloons Chlorine gas

Look at the things around you. Can you name two examples
of solids, liquids and gases?

52 Matter

Model of matter

Scientists use the particulate model of matter to describe
how the arrangement of particles in solids, liquids and
gases differs. The table below shows the properties of
solids, liquids and gases.

Properties Solids Liquids Gases

Arrangement The particles are: The particles are: The particles are:
• strongly attracted • attracted to each • weakly attracted
other; to each other;
to each other;

• packed very • packed closely • far apart from
closely together; together; each other;

Movement • arranged in a • not arranged in a • not arranged in a
Shape fixed, regular fixed, regular fixed, regular
pattern. pattern.
pattern.
• The particles • The particles • The particles
vibrate in their move over short move freely in

fixed position. distances. any direction.
• A solid has a • A liquid has no • A gas has no
definite shape. definite shape. It
takes up the shape definite shape. It
Volume • A solid has a of its container. fills its container.
definite volume. • A liquid has a
definite volume. • A gas has no
definite volume.

Differences in the properties of solids, liquids and gases based on the particulate model
of matter

Quick Check ?

1. What are the different states of matter? You have learnt
2. Identify the different states of matter in a can of about density in
Chapter 1. Can you
carbonated soft drinks. explain why solids
3. Describe the properties of solids, liquids and gases in are denser than
gases?
terms of how the particles are arranged.
4. Draw the particulate model of matter and describe Matter 53

the differences in the movement of particles in solids,
liquids and gases.

3.3 Diffusion

You should be able to:
• def ine diffusion as the random movement of particles;
• explain briefl y, diffusion in solids, liquids and gases, in terms

of the movement of particles.
Have you noticed that a scent quickly spreads across a room?
Air freshener is usually sprayed to remove unpleasant smells.
It takes only a few seconds for the gaseous scent particles to
spread throughout the room.
The spreading of smells can be explained using the movement
of gas particles. The gaseous particles of the scent move
about randomly in all directions. This allows them to spread
and f ill the room. The spreading of particles by random
movement is called diffusion.

Durians and dried shrimp emit very strong, pungent smells.

When you pass by stalls selling durians or dried shrimp, the
strong smell of the food quickly reaches your nose. This is due
to diffusion.

Try this

StTanrdy at tah ciosrner of the classroom and spray air freshener

into the air. Get your classmates to raise their hands when
they f irst smell the air freshener.

54 Matter

Let us take a look at some examples of diffusion.

Example 1: Diffusion in solids
Place a few copper (II) sulfate crystals in a test tube containing clear jelly. Leave the
set-up to stand and observe it from time to time.

Jelly Jelly Jelly

Copper Copper Copper
(II) (II) (II)
sulfate sulfate sulfate
crystal diffused diffused
up the further up
jelly the jelly

At the start of the After two days After a week
experiment

The copper (II) sulfate particles will slowly diffuse upwards in the clear jelly.

Example 2: Diffusion in liquids
Place a few drops of potassium permanganate at the bottom of a beaker containing
water. Leave the set-up to stand and observe it from time to time.

Water

Potassium
permanganate

At the start of the After two hours After one day
experiment

The potassium permanganate will diffuse throughout the water.

WB Link Activity 3.1
Matter 55

Example 3: Diffusion in gases
Place a few drops of liquid bromine in a gas jar and invert another gas jar over it. Remove
the lid between the jars. Leave the set-up to stand and observe it from time to time.

Gas jar Air Reddish-brown
Lid (colourless vapour spreads
gas) throughout
both gas jars
Remove lid after some time

Reddish-brown Gas
vapour of jars
bromine

Drops of liquid bromine

At the start of After 10 minutes After one hour
the experiment

The reddish-brown vapour of bromine will spread quickly throughout the gas jars.

Safety Precaution! These experiments show that diffusion can occur in all states
Brafoemty Pinreec aiust ipono!isonous. of matter.
This experiment Diffusion takes place faster in gases than in liquids or solids.
should only be This shows that the particles in a gas move around faster than
done as a teacher’s those in solids or liquids. Likewise, diffusion takes place faster
demonstration and in liquids than in solids. This shows that the particles in a liquid
must be carried out move around faster than those in solids.
in a fume cupboard.
Quick Check

1. What is diffusion?
2. Give an example of diffusion.
3. Compare the time taken for diffusion to take place in

the three states of matter.

56 Matter

3.4 Elements, Compounds
and Mixtures

You should be able to:
• define the terms element, compound and mixture;
• recognise that the different elements on Earth are arranged

systematically in the Periodic Table;
• identify some examples of elements, compounds and

mixtures;
• distinguish between the properties of compounds and

mixtures.

Elements cannot be broken down into simpler substances by
chemical methods. They can be classified into metals and
non-metals.
The general differences in the properties of metals and
non-metals can be summarised as follows:

General properties Metals Non-metals

Appearance Shiny, can be polished Usually dull

State of matter at Usually solids Mostly gases and solids
room temperature (bromine is a liquid)

Effect when a force is Malleable — can be beaten Brittle (for solids) — can
applied into sheets and moulded snap or break easily

Density Ductile — can be drawn Non-ductile
Melting point and into wires without breaking
boiling point High Low
Electrical conductivity High Usually low
Heat conductivity
Good Usually poor
Good Poor

General properties of metals and non-metals

Science Bites

There are some exceptions to the general properties listed in the table
above. Some of the exceptions are:
• Mercury is a metal that is a liquid at room temperature. It has a low

melting point.
• The metal gallium is a brittle solid at room temperature but melts

when held in the palm of your hand.
• Graphite is a form of the non-metal element, carbon, but it is a good

conductor of electricity.

Matter 57

Elements

Different elements have different properties that make
them suitable for certain uses. Here are some examples of
elements, their properties and uses.

Copper is often used Copper Copper is used for
to make pipes, e.g. • It is a reddish-brown, electrical wiring.
hot water pipes and
gas pipes. metallic solid. Silver is coated
• It is a good on glass to
Silver can be used make mirrors.
to make cutlery. conductor of
electricity.
• It is ductile.
• It is resistant to
corrosion.
• It is strong.
Silver
• It is a shiny,
metallic solid.
• It is a good
conductor of heat
and electricity.
• It is ductile.

Gold is commonly Gold
used to make • It is a yellow,
jewellery.
metallic solid.
• It is ductile. Iron can be used
• It is resistant to make gates.

to corrosion.
• It is a very good

conductor of heat
and electricity.
Iron
• It is a grey, metallic
solid.
• It is a good
conductor of heat
and electricity.
• It is ductile.
• It is strong.
• It is a magnetic
substance.

58 Matter

Sulfur Sulfur helps to Science Bites
• It is a yellow, make rubber
tyres tougher Vulcanisation is the
non-metallic solid. through process by which
• It is soluble in ‘vulcanisation’. rubber is made
stronger, by adding
organic solvents sulfur to it. This
(e.g. alcohol) but process means
not in water. rubber can have a
Carbon (Diamond) wider range of uses,
• It is a non-metallic solid. e.g. soles of shoes,
• It can be polished to tyres, toys, etc.
form a shiny, refl ecting,
transparent solid. Diamond-tipped drills are
• It is a non-conductor of used to cut through very
electricity. hard metals and rocks.
• It is the hardest natural
substance.
Carbon (Graphite)
• It is a black,
non-metallic solid.
• It is lightweight.
• It is a good
conductor of
electricity.

Graphite is used to
make racket frames.

Hydrogen
• It is a colourless gas.
• It is the gas with the

lowest density.
• It is explosive when

mixed with oxygen.

Hydrogen fuel cell used in a car
does not give out carbon dioxide
when it burns.

Oxygen Oxygen is mixed with
• It is a colourless gas.
• It is essential for life. acetylene to produce a
• It does not burn but very hot flame for welding.

supports combustion.

Oxygen is given to patients
during surgical procedures.

Matter 59

60 Matter Periodic Table
To study the properties of elements systematically, scientists ha
Periodic Table.

The Periodic Table organises element

Elements Group Æ
arranged in the
same vertical Period I II
column belong Ø
to the same
group and have 1 H
similar chemical
properties. Hydrogen

1

2 Li Be

Lithium Beryllium

3 4

Elements arranged in 3 Na Mg
the same horizontal
row belong to the Sodium Magnesium
same period. As
we move from left 11 12
to right along one
period, the properties 4K Ca Sc Ti V Cr Mn Fe Co
of elements gradually
change from those Potassium Calcium Scandium Titanium Vanadium Chromium Manganese Iron Cobal
of metals to those of
non-metals. 19 20 21 22 23 24 25 26 27

5 Rb Sr Y Zr Nb Mo Tc Ru Rh

Rubidium Strontium Yttrium Zirconium Niobium Molybdenum Technetium Ruthenium Rhodiu

37 38 39 40 41 42 43 44 45

6 Cs Ba La Hf Ta W Re Os Ir

Caesium Barium Lanthanum Hafnium Tantalum Tungsten Rhenium Osmium Iridium

55 56 57 72 73 74 75 76 77

7 Fr Ra Ac

Francium Radium Actinium

87 88 89

*58 – 71 Lanthanoid series Ce Pr Nd Pm Sm
†90 – 103 Actinoid series
Cerium Praseodymium Neodymium Promethium Samariu

58 59 60 61 62

a a = mass number Th Pa U Np Pu
X = chemical symbol
Key X b = proton (atomic) number Thorium Protactinium Uranium Neptunium Plutoniu

b 90 91 92 93 94

The Periodic Table

Science Smart

The chemical symbol of an element is usually the f irst few letter
element’s name. But there are some exceptions. The chemical s
copper, for example, is ‘Cu’ and not ‘Co’. This is because original
elements were named using Latin. Copper in Latin is called cupr

ave organised all the discovered elements into a table called the

The names of elements are represented
by chemical symbols. For example,
carbon is represented by ‘C’, whereas
ts. chlorine is represented by ‘Cl’.

III IV V VI VII 0

He

Helium

2

B C N O F Ne The elements on
the left side of
Boron Carbon Nitrogen Oxygen Fluorine Neon this zigzag line
are classif ied
5 6 7 8 9 10 as metals, and
those on the right
Al Si P S Cl Ar are classif ied as
non-metals. The
Aluminium Silicon Phosphorus Sulfur Chlorine Argon elements near
this zigzag line
13 14 15 16 17 18 have some of
the properties of
o Ni Cu Zn Ga Ge As Se Br Kr both metals and
non-metals.
lt Nickel Copper Zinc Gallium Germanium Arsenic Selenium Bromine Krypton

28 29 30 31 32 33 34 35 36

h Pd Ag Cd In Sn Sb Te I Xe

um Palladium Silver Cadmium Indium Tin Antimony Tellurium Iodine Xenon

46 47 48 49 50 51 52 53 54

Pt Au Hg Tl Pb Bi Po At Rn

m Platinum Gold Mercury Thallium Lead Bismuth Polonium Astatine Radon

78 79 80 81 82 83 84 85 86

m Eu Gd Tb Dy Ho Er Tm Yb Lu

um Europium Gadolinium Terbium Dysprosium Holmium Erbium Thulium Ytterbium Lutetium

63 64 65 66 67 68 69 70 71

u Am Cm Bk Cf Es Fm Md No Lr

um Americium Curium Berkelium Californium Einsteinium Fermium Mendelevium Nobelium Lawrencium

95 96 97 98 99 100 101 102 103

rs in the
symbol for
lly, many
rum.

Compounds

A compound is a substance that is made up of two or more
different elements chemically combined together. Here are
some common examples of compounds.

Water is a compound of oxygen Sodium chloride (table salt) is a
and hydrogen. compound of sodium and chlorine.

Carbon dioxide is a compound Sodium hydroxide is a compound of
of carbon and oxygen. sodium, oxygen and hydrogen.

Copper sulfate is a compound Sugar is a compound of carbon,
of copper, sulfur and oxygen. hydrogen and oxygen.

Matter 61

Properties of compounds
The properties of a compound are usually different from those
of its elements.

+

Sodium is a soft Chlorine is a Sodium chloride (table
metallic solid. greenish-yellow salt) is a white solid.
It reacts violently poisonous gas. It is non-poisonous.
with water. It dissolves in water but it
does not react with water.

The elements that make up table salt (sodium chloride)

How are compounds formed?
There are a number of ways of producing a compound.
For example:

i) Two elements can react to form a compound.

Element + Element Compound

Example:

carbon + oxygen carbon
dioxide
(element) (element) (compound)

ii) An element and a compound can react to form
another compound.

Element + Compound Compound + Element

Example:

calcium + water calcium + hydrogen
hydroxide
(element) (compound) (compound) (element)

62 Matter

iii) Two different compounds can react to form other compounds.

Compound + Compound Compound + Compound

Example:

iron + sodium iron + sodium
chloride hydroxide hydroxide chloride
(compound) (compound) (compound) (compound)

WB Link Activity 3.2

How can compounds be broken down?
Compounds can be broken down by chemical methods.
Water can be broken down into its constituent elements —
hydrogen and oxygen — by passing an electric current through
it. This process is called electrolysis.

Oxygen Hydrogen

Carbon Water
electrodes containing
a little
sulfuric
acid

Battery (6 V) WB Link Activity 3.3
Matter 63
Water being broken down into hydrogen and
oxygen by electrolysis

Mixtures

A mixture consists of two or more different substances
that are mixed but not chemically combined together.
The substances that make up a mixture may be elements,
compounds or both elements and compounds. Examples of
mixtures are air, sea water and crude oil.
Air is made up of a mixture of gases including nitrogen,
oxygen, carbon dioxide, water vapour and noble gases. They
can be separated by physical methods, for example, fractional
distillation.

Properties of mixtures

Properties of mixtures Properties of air

When a mixture is formed, no Air is formed by simply
chemical reaction occurs. mixing its constituent gases
— nitrogen, oxygen, carbon
dioxide, water vapour and
noble gases. No reaction occurs
between the components.

A mixture has the properties Air has the properties of its
of its constituent substances. constituent gases — nitrogen,
oxygen, carbon dioxide, water
vapour and noble gases. Air
supports combustion because
the oxygen it contains supports
combustion.

A mixture can be separated Air can be separated into its
easily by physical methods constituent gases by fractional
(i.e. without involving chemical distillation.
reactions).

? The constituents in mixtures The proportions of the
are not in any fixed proportion. constituent gases in air may
Is salt water a vary with place and time. For
mixture? Can example, there is a higher
you name two proportion of carbon dioxide
compounds that in the city compared to the
make up salt water? jungle.

Comparing the similar properties of mixtures and air

64 Matter

The picture below shows Brunei Darussalam’s oil ref inery
where crude oil, a mixture, is separated. Crude oil undergoes
fractional distillation to separate its components.

Science Bites

Fractional distillation
is used to separate a
mixture of more than
two liquids according
to their different
boiling points.
Components with a
lower boiling point
boil out f irst.

Oil refinery in Brunei Darussalam

Oil wells Petroleum ?
Oil tankers gas
Petrol Can you name the
(gasoline) components found in
Naphtha crude oil?
Kerosene
(paraff in) Matter 65
Diesel

Lubricating
oil

Furnace Bitumen
for heating
crude oil

Separation of crude oil by fractional distillation

Link It

Learn more about separation techniques in Chapter 4.

Differences between compounds and mixtures
A summary of the differences between compounds and
mixtures is shown below.

Compounds Mixtures
Fixed proportions of Constituents are not
constituents. necessarily in f ixed
proportions.
They are formed by chemical They are not formed by
reactions. chemical reactions.
They cannot be broken down They can be broken down by
by physical methods. physical methods.

Differences between compounds and mixtures

Quick Check

1. What is an element?
2. Why are water and carbon dioxide not found in the

Periodic Table?
3. Give three examples of (i) mixtures and (ii) compounds.
4. What are the differences between compounds and

mixtures?

WB Link Activity 3.4 Science Bites

Do you know that pure gold
is not suitable for making
jewellery? This is because it
is too soft and changes shape
easily. To make gold hard
enough to retain its shape, it is
mixed with other metals such as
silver, copper and zinc.

66 Matter

Example 1
Consider the elements in the box.

Iron Sulfur Gold Silver
Copper Bromine Nitrogen Iodine

a) Classify the elements into metals and non-metals.
b) The properties of one of the elements in the box are listed

below.
• It allows an electric current to pass through it easily.
• It can be hammered without breaking.
• It is a magnetic substance.
Identify the element.

Solution
a) In the Periodic Table, the elements on the left of the zigzag line

are metals and those on the right are non-metals. Therefore,
by looking at the Periodic Table, we can identify the following:
• Metals: copper, iron, gold and silver
• Non-metals: sulfur, bromine, nitrogen and iodine

b) Iron

Example 2
Study the following list of substances.

Sugar Steel Clean air
Table salt Bronze Orange juice

a) Classify the substances given as compounds or mixtures.
b) What are the differences between compounds and mixtures?

Solution
a) Compounds: sugar and table salt (sodium chloride)
Mixtures: steel, clean air, bronze and orange juice

b) Compounds Mixtures

• They are separated into • They are separated into their
their constituents using constituents using physical
chemical methods. methods.

• They have f ixed • The constituents are not
proportions of constituents. necessarily in f ixed proportions.

• The constituents are • The constituents are mixed
chemically combined. together.

Matter 67

Summary Matter

is made up of

Elements

are

chemically mixed to form systematically broadly classif ied
combined to form arranged in the into

Periodic Table

Compounds Mixtures Metals Non-metals
have different have properties have general have general
properties from of the substances
their elements they are made of properties properties
such as such as

• Fixed • Substances • Shiny • Dull
proportion of are not • Solid at room • Usually
elements in f ixed
proportions temperature solid or gas
• Formation • Malleable at room
and breaking • Formation • Ductile temperature
down involve and breaking • High density • Brittle
chemical down do • High melting • Non-ductile
reactions not involve • Low density
such as chemical and boiling • Low melting
electrolysis and reactions points and boiling
combustion (i.e. they are • Good points
separated conductors • Poor
by physical of heat and conductors
methods) electricity of heat and
electricity

68 Matter

Review Questions

1 How are steam and ice similar?
A They can be compressed.
B They can take the shape of any container.
C They consist of the same type of particles.
D Their particles have the same amount of energy.

2 In which substance are the particles most strongly attracted to
one another?

A Ice
B Water
C Steam
D Cold Water

3 The diagram on the right shows particles in a particular substance.
What can you infer from the diagram?

A The substance cannot be compressed further.
B The substance has a def inite shape and volume.
C The particles are vibrating about in their f ixed positions.
D The particles have large amounts of energy so they move
randomly and quickly.

4 Which of the following is not an example of diffusion of particles?
A Smelling smoke from burning incense.
B Water fl owing onto the road from a burst water pipe.
C Smelling a fragrant scent from an open bottle of perfume.
D Chemicals spilling into a reservoir and contaminating the water.

5 The following elements are non-metals, except
A chlorine gas
B sulfur powder
C liquid mercury
D iodine crystals

6 Which of the following substances is a compound?
A Air
B Gold
C Steel
D Water

Matter 69

7 What happens when a mixture is formed?
A A new product is formed.
B A chemical change takes place.
C The constituents are present in variable amounts.
D It has properties that are different from the properties of

its constituents.
8 Using the particulate model of matter, describe the differences in

the arrangement and movement of particles in wood, sea water and
oxygen.
9 List the differences in the properties of solids, liquids and gases based
on their shape and volume. Tabulate your answers.
10 Classify the following substances according to their states of matter at
room temperature.

Carbon dioxide Mercury Dry ice
Coffee powder Cotton wool Spray of deodorant

11 Maria f illed a balloon with air, tied it up and left it for a few days.
a) Predict what happens to the balloon after a few days.
b) Explain your prediction in part a).

12 What are the differences between metals and non-metals in terms of:
a) Heat conductivity
b) Electrical conductivity
c) Malleability and ductility
d) Melting and boiling points

13 Hakim adds a small piece of sodium to a beaker of water. The sodium
moves about quickly on the surface of the water producing a hissing
sound. It gets smaller and smaller until it disappears. The word
equation for the reaction that occurs is:

sodium + water sodium hydroxide + hydrogen

A solution of sodium hydroxide is left at the end of the reaction. State
whether each of the following is an element, compound or mixture.

a) Water
b) Sodium
c) Hydrogen
d) Solution of sodium hydroxide

70 Matter

14 A mixture of salt and sand can be separated by the
same method as a mixture of iron f ilings and sand.

Is the above statement true? Explain.
15 A mixture of ethanol (boiling point 78 °C) and water
(boiling point 100 °C) is distilled. Which liquid would be collected f irst?
Why?
16 State whether each of the following statements is true or false. Give a
reason for each of the false statements.

a) Crude oil cannot be separated into its constituents.
b) The constituents in a mixture retain their own properties.
c) Sugar is an element that cannot be broken down into simpler

substances.
d) The properties of water are the same as the properties of hydrogen

gas and oxygen gas.
17 All living things need air for survival. Air consists of a number of

gases in varied amounts. Approximately 0.03% of air is made up of
carbon dioxide gas.
a) Is air a compound or a mixture?
b) Name at least three other constituents of air.
18 a) Is sea water an element, a compound or a mixture?
b) Is pure water an element, a compound or a mixture?
c) What are the differences between compounds and mixtures?

Matter 71

Chapter Water

4 The picture shows the commemorative man-made lagoon on
the banks of the Brunei River near Kampong Ayer (The Water
Village). The estimated population of the village is 39,000 –
this is roughly ten percent of Brunei’s total population. The
buildings, including homes, mosques, schools, a convenience
store and a clinic, are built on stilts on the water and linked by
waterways.

Firman Allah Subhanahu Wa Ta’ala
Tafsirnya:
Dia membiarkan air dua laut (yang
masin dan yang tawar) mengalir,
kemudian bertemu (pada pandangan
mata). (19) Di antara kedua-keduanya
ada batas yang memisahkannya,
masing-masing tidak melampaui
sempadannya. (20) Maka, ni’mat
Tuhan kamu yang manakah yang kamu
hendak dustakan? (21) Dari kedua-dua
laut itu, keluar mutiara dan marjan
(batu permata yang berwarna merah).
(22)

He has let loose the two seas (the salt
and fresh water) meeting together.
(19) Between them is a barrier which
none of them can transgress. (20) Then
which of the Blessings of your Lord will
you both (jinn and men) deny? (21)
Out of them both come out pearl and
coral. (22)

(Surah Ar-Rahman: 19-22)

Let’s Explore

• What are the changes of states of
water?

• What are some simple techniques
for separating mixtures?

• In what ways can we conserve
water?

72 Water

4.1 States of Water

You should be able to:
• state the three states of water: solid (ice), liquid (water)

and gas (steam);
• explain the changes of states of water with reference to

boiling, melting, condensation, freezing and evaporation;
• recognise that the changes between the states of water

can occur at different temperatures and state that:
– boiling point of pure water is 100 °C,
– melting point of pure ice is 0 °C, and
– freezing point of pure water is 0 °C;
• distinguish between evaporation and boiling in terms

of temperature.

In Chapter 3, you have learnt about the three states of
matter and their differences. Water can exist in all three
states. The pictures below show the three states of matter
in which water can exist.

Steam is an
invisible gas.

Ice (water in a solid state)

Sea water (water in a liquid state) Steam (water in a gaseous state)

Water 73

Changes of states of water

A change of state occurs when water gains or loses heat.
To explain the changes in the states of matter, the model of
matter can be used.
Boiling
When water is heated to 100 °C, it will change from a
liquid to a gas called steam. This is known as boiling. The
temperature at which water changes to steam is called its
boiling point. The temperature of water remains constant
at 100 °C during boiling.

Steam

Bubbles are formed throughout
the water during boiling.

Evaporation
When water gains enough heat from its surroundings, it
will change from a liquid to a gas called water vapour. This
is known as evaporation. Evaporation occurs all the time.
It can also occur at any temperature.

Water evaporates from wet clothes,
thus making them dry.

74 Water

During boiling and evaporation, heat is absorbed by the
water. This heat gives the water particles more energy
and causes them to vibrate more vigorously and move
further apart.
The table below summarises the differences between boiling
and evaporation.

Boiling Evaporation

It occurs at a fixed It occurs at any
temperature (boiling point). temperature.

It takes place throughout It takes place on the
the liquid. surface of the liquid.

There are bubbles formed There are no bubbles
throughout the liquid. formed.

The temperature of water The temperature of water
remains constant. is not constant.

Differences between boiling and evaporation

Condensation
Have you noticed that when a glass of cold water is left
on the table, droplets of water form on the outside of the
glass? Where does the water come from?
When warm water vapour (gas) from the surrounding
air touches the cooler surface of the glass, it loses heat.
It will change from a gas to a liquid. This is known
as condensation.

Water vapour condenses on the cool surface WB Link Activity 4.1
Water 75

Melting
Ice is water in its solid state. When taken out of the freezer,
ice cubes are brought into an area of higher temperature
than inside the freezer. This causes the ice cubes to change
from a solid to a liquid. This is known as melting. The
melting point of ice is 0 °C.

WB Link Activity 4.2 Ice melts at 0 °C

During melting, heat is absorbed. The particles of water
in the solid state gain more energy. They vibrate more
vigorously and become randomly arranged.
Freezing
When water is cooled, it changes from a liquid to a solid.
This is known as freezing. The freezing point of pure
water is 0 °C.

Science Bites Snow

Snow is formed Quick Check
when water in the
atmosphere freezes, 1. What are the three states of water?
forming ice crystals. 2. Explain the changes of states of water.
These ice crystals 3. What are the differences between boiling and
may remain in the
atmosphere or they evaporation?
may fall to Earth as 4. What is the freezing point of pure water?
snowfl akes.

76 Water

The following is a summary of the changes of the states Science Smart
of water. The red arrows represent heat gained during
the process. The blue arrows represent heat lost during The boiling point of
the process. water can increase
(above 100 °C) when
Solid Melting Liquid Boiling/ Gas salt, sugar or even
Freezing Evaporation honey is added.
Similarly, the freezing
Condensation point of water can
decrease (below
4.2 Water as a Solvent 0 °C) when other
substances are added
You should be able to: to it. Therefore, when
• describe water as a solvent that can dissolve a solute to we say water boils at
100 oC and freezes at
form a solution; 0 °C, we are referring
• state that gases also dissolve in water with reference to only to pure water.

oxygen and carbon dioxide.

Add a teaspoon of sugar to a glass of water and stir it. What
happens to the sugar? It dissolves in the water to form a
solution because sugar is soluble in water.
The substance that dissolves (the sugar) is the solute. The
substance in which the solute dissolves (the water) is the
solvent. Together, they form the solution.
A substance may be soluble in one solvent but insoluble in
another. Water is a common solvent as many substances
dissolve in it.

Sugar + Water Sugar solution
(Solute) (Solvent) (Solution)

Solute Solution
Solvent

Forming a solution

Water 77

?

Identify the solutes and the solvent in
a cup of sweetened black coffee.

Not all solutes that dissolve in water are solids. Gases such
as carbon dioxide and oxygen may also be dissolved in
water. Carbonated drinks contain dissolved carbon dioxide.

Science Bites

The hissing sound
you hear when
you open a can of
carbonated drink is
caused by carbon
dioxide being
released.

Carbonated (or fizzy) drinks

Dissolved oxygen is essential for aquatic life. Many marine
animals, such as f ish, have gills to absorb dissolved oxygen
in water.

Quick Check Fish have gills to take in dissolved oxygen

1. What is a solvent?
2. What is a solute?
3. How is a solution

formed?

78 Water

4.3 Separation Techniques

You should be able to:
• recognise appropriate techniques for separating constituents

of mixtures by physical means with reference to filtration,
evaporation, distillation and paper chromatography;
• interpret chromatograms in terms of the number of different
dyes present.

You have learnt about mixtures in Chapter 3. Some
examples of mixtures are air, sea water and petroleum.
Many different methods can be used to separate mixtures.
These depend on the physical properties of the components
present and the substance to be obtained.
The following separation methods are known as physical
methods because the processes do not involve chemical
changes. Mixtures can be separated by:
i. filtration,
ii. evaporation,
iii. distillation, and
iv. paper chromatography.

Filtration

Filtration can be used to separate an insoluble solid from
the liquid in a mixture.
The figure below shows a set-up for filtration in the
laboratory. The filter paper has tiny pores that allow the
liquid to pass through. The insoluble solid particles that are
too large to pass through the filter paper are left behind.
The insoluble solid is called the residue and the liquid that
passes through the filter paper is called the filtrate.

Filter paper Magnified Large insoluble
Residue view particles (solid)
Filter funnel are trapped by
the filter paper.
Small particles of
liquid pass through
the filter paper.

Filtrate Water 79
A laboratory set-up for filtration

Uses of filtration
Filtration is a useful process used in our everyday lives as
well as in industries. In most countries, f iltration is one of
the stages of water treatment. The raw water is f iltered
through layers of sand beds, which contain sand grains of
different sizes. Filtration is an economical method used to
remove solid silt and sand particles from water.

Raw water

Fine sand
Gravel
Pebbles

Clear water

Sand filters help to trap suspended particles while
allowing clear water to run through.

Many industries, such as the textile industry, treat their
waste water before recycling for further use. Water
treatment f ilters out the chemicals, organic substances
and minerals.

Waste water Filtered water
Residue

Filter

Air pressure
to push water
through the f ilter

Filtration in industries

80 Water

Evaporation

Evaporation is used to separate a dissolved solid (solute)
from a liquid. We can use evaporation to separate salt from
sea water, as shown in the f igures below. When the liquid
in the mixture has completely evaporated, the residue is
the solid salt.

Evaporating dish Mixture

Residue

A laboratory set-up for evaporation

WB Link Activity 4.3

Uses of evaporation
In some parts of the world, salt is extracted from sea water.
The sea water is allowed to fl ow into large fl at areas called
salt pans. The Sun helps to evaporate the water, leaving
salt behind.

Salt mining

Water 81

Try This Distillation

Draw the cross- Distillation is used to separate a liquid from a solution.
sectional diagram of The two main processes involved in distillation are boiling
the distillation set-up. and condensation. The liquid collected from distillation is
called the distillate. The f igure shows a set-up for simple
Science Bites distillation in the laboratory.

Boiling chips are Thermometer
small pieces of
material, used in Water out
distillation and
heating, to ensure The water vapour
smooth boiling. In enters the condenser.
the laboratory, you
may use porcelain
chips or pieces of
broken ceramic pots
as boiling chips.

The mixture Salt solution
is heated
in a round- Boiling Water in
bottomed fl ask chips
until it boils.

The distillate is
collected in the
conical fl ask.
A laboratory set-up for distillation of salt solution

Uses of distillation
Distillation of water
Distillation is a water purifi cation process. It removes
impurities such as heavy metals, bacteria and viruses.
Bottled distilled water can be found in supermarkets and
pharmacies.

Bottled distilled water

82 Water

Desalination
Desalination refers to a process that removes salts and
minerals from sea water. This will convert undrinkable sea
water to drinking water. Let us look at how this is done.
Firstly, the sea water is heated to 115 °C. This boils the
seawater. The water will evaporate and condense leaving
the salt behind.

Cool surface
on which
water vapour
condenses
Water vapour
rises

Condensed Boiling sea water
water is
collected here

Desalination using distillation

WB Link Activity 4.4

Paper Chromatography

Paper chromatography is used for separating small amounts
of mixtures. This is usually used to separate mixtures of
coloured substances such as inks and dyes.

Maximum height reached
by solvent (solvent front)
before chromatogram is
removed.
Chromatography paper

Ink spot The different dyes in the ink
Solvent mixture travel at different
rates along the paper.

Chromatogram

How paper chromatography is carried out

Water 83

Paper chromatography makes use of the fact that different
substances are carried at different speeds by a solvent.
This property enables various substances in a mixture
to be separated on the chromatography paper. The
resulting paper with the different coloured spots is called
a chromatogram.
Paper chromatography is especially useful in determining
the different types of dyes that can be found in food. Food
scientists are able to identify individual dyes based on the
speed and distance travelled on the paper chromatogram.

Try This

You can perform a paper chromatography experiment in
school. Take a filter paper and place a black ink dot (spot) in
the middle with a pen or marker. Then, using a dropper, drop
one drop of ethanol onto the spot. Leave the paper to air dry.
At the end of this activity, you will see two different-coloured
rings – blue and yellow rings. These rings are the dyes
present in the ink.

Dropper
containing
ethanol

Filter Ink
paper spot

A simple chromatography experiment

Blue ring

Yellow ring

The separation of ink by chromatography

84 Water

Uses of paper chromatography
To determine the dyes used in ink
Paper chromatography can be used to separate a mixture
of dyes. This allows us to f ind out the dye composition
of different inks. This is useful especially in investigating
cases of forgery to f ind out if someone has tampered with
a written document. Paper chromatography is carried out
on different sections of a suspect document. If the results
of the chromatograms do not match, the documents may
have been forged.

To determine the dyes used in food
Food colourings are often used in candies, cakes and soft
drinks to make them look more appealing. However, there
are certain types of food colourings that can cause adverse
effects in our body. Paper chromatography can be used to
identify different types of dye and thus help ensure that
harmful ones are not used in food products.

Different types of food made with colouring WB Link Activity 4.5
Water 85
Quick Check

1. Identify the residue and the f iltrate that are obtained
from the f iltration of a mixture of sand and water.

2. What is the pure liquid obtained by distillation called?
3. What are some uses of paper chromatography?

4.4 Uses and Conservation
of Water

You should be able to:
• state the uses of water in homes and industries;
• describe some methods of water conservation.

Brunei Darussalam gets its water resources from these four
major rivers: the Temburong, Belait, Tutong and Brunei rivers.
Brunei Darussalam has two large dams that hold the majority
of the stored water within the country. Water is important to
living things. Besides drinking, water is also widely used in
homes and industries.

Domestic uses

Some uses of water include cleaning, cooking and watering
plants.

Cooking Washing dishes
Watering plants
86 Water

Industries

Water is not only used in homes but in industries as well.
Agriculture, mineral water industries, textiles and oil
ref ineries depend heavily on water.

Water is largely used in agriculture.

Water is used as a solvent in the manufacture
of beverages.

Science Bites

Water can be used to generate electricity too. Water in
hydroelectric power plants falls from a height and fl ows through
turbines. The turbines spin and produce electricity. The faster
the turbines spin, the more electricity they generate.

Water 87

Ways of conserving water
With the population of Brunei Darussalam increasing, the
demand for water is also increasing. We should not take the
supply of water for granted. Instead, we should use water
carefully. Using water wisely and not wasting it is known as
water conservation.
Here are some ways that you can save water at home.
1. Wash dishes in a tub of water instead of under a

running tap.

2. Use a pail of water to wash the car instead of spraying
water from a hose.

3. Turn off the tap while brushing your teeth. Use a cup of
water to rinse your mouth.

88 Water

4. Reuse water that has been used to wash vegetables to
water your plants.

5. Make sure that there are no leaking or broken taps
and pipes.

Quick Check WB Link Activity 4.6

1. State two uses of water at home.
2. State two uses of water in industries.
3. What is water conservation?
4. What are some methods of water conservation?

Water 89

Summary

Water

exists in acts as a can be is used in needs to be
three states solvent involved in homes and conserved
separation industries
dissolves techniques
solutes to
form solutions Filtration
Evaporation
able to dissolve Distillation
gases such

as oxygen and
carbon dioxide

Paper chromatography

Solid Liquid Gas

Freezing
Freezing point = 0 °C

Ice Water Steam Water vapour

Melting Boiling
Melting point = 0 °C Boiling point = 100 °C

90 Water Evaporation
Occurs at any temperature

Condensation
Cooler temperature than surroundings

Review Questions

1 State the process by which water changes into a solid.
A Boiling
B Melting
C Freezing
D Evaporation

2 What is the boiling point of pure water?
A 0 °C
B 10 °C
C 100 °C
D 1000 °C

3 Which of the following statements is true?
A Evaporation only occurs at 100 °C.
B Boiling occurs at a range of temperatures.
C Water changes from a solid state to a liquid state during freezing.
D Condensation occurs when water vapour becomes water droplets.

4 Which of the following will not form a solution?
A Oil and water
B Sugar and water
C Detergent and water
D Coffee powder and water

5 Identify a solute in f izzy drinks.
A Oil
B Water
C Carbon dioxide
D Aluminium can

6 What is the correct sequence to obtain dry samples of salt and pepper
from a mixture of the two?

A Filter the mixture → Evaporate to dryness → Add water with stirring
B Filter the mixture → Add water with stirring → Evaporate to dryness
C Add water with stirring → Evaporate to dryness → Filter the mixture
D Add water with stirring → Filter the mixture → Evaporate to dryness

7 Which of the following is a method of conserving water?
A Washing the car using a hose
B Having a tap running while brushing your teeth
C Doing a half load of laundry in a washing machine
D Watering plants with water that has been used to wash rice

Water 91

8 Give three differences between boiling and evaporation.

9 State the reason why large particles of a solid can be trapped on a
f ilter paper during f iltration.

10 You have just run some chromatograms on two samples of coloured
inks, X and Y. The results are shown in the diagrams below. Study the
chromatogram and answer the questions that follow.

Before After
Chromatography
paper Solvent
front

Baseline where two Level of
spots of inks X and Y solvent

XY


a) Which ink is likely to be pure? Why?
b) What does the chromatogram tell us about ink Y?
c) Why are the three different spots separated out from ink Y found

at different heights?
11 What method would you use to separate the following mixtures:
a) a liquid from a solution?
b) an insoluble solid from a liquid mixture?
c) a solute from a solution?
d) a mixture of soluble coloured substances?
12 Salmah suspects that she has been given a forged cheque. How can

the forgery be identif ied using one of the scientif ic processes you have
studied?
13 List two ways water is used in industries.

14 List four things you could do to conserve water.

92 Water

Chapter Cell Structure
and Organisation
5
Robert Hooke first introduced the term ‘cells’ in 1665 after
he had examined thin slices of cork using one of the earliest
microscopes. What Hooke saw were only dead cells. Today,
our idea of cells is quite different because modern technology
allows us to study living cells. Let us learn more about cells and
their functions in this chapter.

Firman Allah Subhanahu Wa Ta’ala
Tafsirnya:
Wahai manusia! Apakah yang
memperdayakan kamu (berbuat
derhaka) kepada Tuhanmu yang
Maha Pemurah? (6) Tuhan Yang telah
menciptamu, lalu menyempurnakan
kejadianmu dan menjadikan (binaan
tubuh badanmu) seimbang. (7)
Dalam apa sahaja bentuk dan rupa
yang dikehendakiNya, Dia menyusun
kejadianmu. (8)

O man! What has made you careless
about your Lord, the Most Generous?
(6) Who created you, fashioned you
perfectly, and gave you due proportion.
(7) In whatever form He willed, He put
you together. (8)

(Surah Al-Infitar: 6-8)

Let’s Explore

• What are the different parts
of a microscope and their
functions?

• What are the differences
between an animal cell and a
plant cell?

• How are cells organised in the
human body?

93Cell Structure and Organisation

Super Scientist 5.1 Basic Microscopy
and Scientific
Drawing Skills

You should be able to:
• identify the basic parts of a microscope (mirror, stage,

large knob, small knob, eye piece, objective lenses, tube,
clips) and state the function of each part;
• prepare fresh biological specimens (cheek cell or liver cell,
and onion cell) for observation under the microscope using
iodine solution or methylene blue as a stain;
• perform the proper technique of mounting a specimen;
• draw diagrams of prepared slides of plant and animal cells
observed under the microscope.

The microscope and its functions

Most cells are too small to be seen with our eyes alone.
We can use a microscope to help us see these cells and
their structures. Let us learn more about the different parts
of a microscope and how it helps us see small structures.

Eye piece

The earlier microscope Large knob Tube
was a tube-like device Small knob
with a number of glass Objective lenses
lenses inside. Anton Clips Stage
van Leeuwenhoek Mirror
(1632–1723), a
Dutch tradesman and
scientist, developed
and improved the
microscope. With it,
he was able to observe
yeast, blood cells and
microscopic organisms.

Parts of a microscope

94 Cell Structure and Organisation

The table below describes the functions of the different
parts of a microscope.

Parts of a Functions
microscope It reflects light into the microscope.
Mirror

Stage It is where the microscope slide is placed.

Large knob It moves the stage for a clearer image.

Small knob It adjusts the focus for a sharper image.

Eye piece It contains the lenses that increase the
magnification of the objective lenses.

Objective lenses They increase or decrease the
magnification for viewing.

Tube It connects the eye piece to the objective
lenses.

Clips They hold the microscope slide in place.

Functions of the parts of a microscope

A microscope slide is used to hold the specimen for
microscopic study. There are proper techniques for preparing
fresh specimens for observation and mounting a specimen
on a microscope slide.

You will learn how to use a microscope and the techniques WB Link Activity 5.1
involved in viewing a specimen under a microscope in
the workbook.

Quick Check
1. What are the parts of a microscope?
2. State the functions of the parts of the microscope.

95Cell Structure and Organisation

5.2 Main Structures of
Animal and Plant
Cells

You should be able to:
• identify and draw simple cell structures of animal and plant

cells as seen under a microscope;
• state the functions of the cell wall, cell membrane,

cytoplasm, nucleus, chloroplast and vacuole;
• list the differences between animal and plant cells.

Cells are the basic units of all living things. They are of
different shapes, sizes and structures. However, they do
have some features in common.

An animal cell

The diagram below shows parts of a typical animal cell.

Cell membrane

Cytoplasm

Nucleus

Vacuoles

A typical animal cell seen under Parts of an animal cell
a microscope

Parts of an Functions
animal cell
Cell membrane It is a thin membrane that surrounds the
Cytoplasm cell. It controls substances entering or
leaving the cell.

It is where all chemical reactions take place.

Vacuoles They store water and other nutrients.

WB Link Activity 5.2 Nucleus It controls cell activities and is needed for
the cells to reproduce.

Functions of the parts of an animal cell

96 Cell Structure and Organisation

A plant cell

The diagram below shows parts of a typical plant cell.

Chloroplasts

Cytoplasm

Cell wall Nucleus

Vacuole A typical plant cell seen under
a microscope
Cell
membrane

Parts of a plant cell

Parts of a Functions
plant cell

Cell wall It protects and gives the cell a regular
shape.

Cell membrane It is a thin membrane that surrounds the
cell. It controls substances entering or
leaving the cell.

Cytoplasm It is where all chemical reactions take place.

Chloroplasts They contain a green pigment, called
chlorophyll, which helps to absorb light
energy to make food for the cell during
photosynthesis.

Nucleus It controls cell activities and is needed for
the cell to reproduce.

Vacuole It stores water and other nutrients.

Functions of the parts of a plant cell WB Link Activity 5.3

97Cell Structure and Organisation

The table below summarises the differences between animal
cells and plant cells.

Animal cell Plant cell

Shape Irregularly shaped Regular shaped or
fixed shape

Cell wall Has no cell wall Has a cell wall

Chloroplasts Does not contain Contains chloroplasts
chloroplasts

Vacuole Small and numerous. Usually large and
Some animal cells only one vacuole
have no vacuoles. present.

Differences between an animal cell and a plant cell

Science Bites

The red blood cells in
our blood are the only
cells in our body that
do not have a nucleus.
Without this large
structure in the cell, it
can carry more oxygen.
However, because
it has no nucleus, it
cannot reproduce.

Quick Check

1. Identify the parts and functions of an animal cell.
2. Identify the parts and functions of a plant cell.
3. State the similarities between an animal cell and a

plant cell.
4. State the differences between an animal cell and a

plant cell.

98 Cell Structure and Organisation