Science_Form_3

4. Heating of calcium carbonate is an – Hence, the large plastic bag functions
endothermic reaction. Heat is absorbed by as an instant hot pack.
the chemical reaction that occurs during
the decomposition of calcium carbonate. Instant cold pack:
– Use toothpick to prick a hole in the
5. The reaction between hydrochloric acid
and sodium carbonate is an exothermic small plastic bag so that water flows
reaction whereas the reaction between out from the plastic bag and mixes
hydrochloric acid and sodium hydrogen with the ammonium nitrate powder in
carbonate is an endothermic reaction. the large plastic bag.
– Dissolving of ammonium nitrate in
6. Replanting of trees will increase the rate water is an endothermic reaction which
of photosynthesis. As photosynthesis is cools down the large plastic bag.
an endothermic reaction, more heat will – Hence, the large plastic bag functions
be absorbed from the surroundings into as an instant cold pack.
the plants to carry out photosynthesis.
Hence, the surrounding temperatures will CHAPTER 6 Electricity and
drop. Magnetism

7. (a) Thermite reaction is an exothermic Activity 6.1 (p. 165)
reaction because heat is released Questions
into the surroundings. 1. Electric current
2. Cutting of magnetic field lines (by copper
(b) In a thermite reaction, heating
of iron(II) oxide, aluminium and wire or coil of wire)
magnesium tape produces iron and 3. Induced current
carbon dioxide through an exothermic
reaction. The heat released in this Activity 6.2 (p. 166)
reaction increases the temperature of Questions
the iron and carbon dioxide until the 1. (b)
iron melts. This molten iron is used to
repair and reconnect the broken iron (c)
railway rails. 2. Induced current is detected based on the

8. lighting up of the LED. Induced current
is produced and flows through the LED.
Large plastic Therefore the LED lights up.
bag 3. Current is induced when magnetic field
lines are cut.
Toothpick 4. Sound energy, heat energy, light energy
5. – LED lasts longer and does not burn
Small plastic
bag out easily
– LED will light up when electric current
Water
flows through as compared to filament
Calcium chloride bulb which only lights up when its
or ammonium filament is hot enough.
nitrate powder
Activity 6.4 (pp. 172 – 175)
Instant hot pack: Questions
– Use toothpick to prick a hole in the 1. To show the shape of graph, direction

small plastic bag so that water flows of current and voltage change for direct
out from the plastic bag and mixes current and alternating current.
with the calcium chloride powder in the 2. Similarity: Magnitude of the
large plastic bag.
– Dissolving of calcium chloride in water displacement of the light
is an exothermic reaction which heats spot from the zero position
up the large plastic bag.
13

in steps 6 and 8 is fixed and Formative Practice 6.1 (p. 176)
the same. This shows that 1. Renewable energy sources are energy
the voltage of the battery is
fixed and of the same value. sources that can be replaced continually
Difference: Displacement of the light and will not deplete while non-renewable
spot from the zero position energy sources are energy sources that
in step 6 is positive while cannot be replaced and will deplete.
displacement of the light spot 2. (a) LED lights up in arrangements P
from the zero position in step
8 is negative. This shows that and Q. In arrangements P and Q,
the current in step 6 flows magnetic field lines are cut by the
from positive to negative coil of wire to produce induced
whereas in step 8 the flow current. This induced current flows
of current in the C.R.O. has through the LED causing the LED to
been reversed. light up.
3. (a) First inference: (b) LED does not light up in arrangement
The different position of the straight R. In arrangement R, there is no
line on the display screen in steps cutting of magnetic field lines and
7 and 9 shows that direct current is no induced current flows through the
the electric current which flows in the LED.
opposite direction. 3. To show the shape of graph, direction
(b) Second inference: of current and voltage change for direct
The position of the straight line from current and alternating current.
the zero position in steps 7 and 9
which are different shows that direct Experiment 6.1 (pp. 178 – 180)
current in steps 7 and 9 flow in the Questions
opposite directions. 1. (a) Bulb P is brighter compared to
4. Voltage produced by the power supply
keeps changing. Hence, the light spot bulb S.
on the screen moves up and down to (b) Vp > VS
produce a vertical trace on the screen (c) Step-down transformer
irrespective of the type of terminal 2. (a) Bulb S is brighter compared to
connection to the C.R.O.
5. (a) First inference: bulb P.
The shape of graph on the display (b) Vp < VS
screen produced by the vertical and (c) Step-up transformer
horizontal trace made by a light 3. If the difference between the number
spot shows continuous change in of turns in the primary coil and the
the direction of current flow and the number of turns in the secondary coil in
voltage of the alternating current. a transformer is increased, the difference
(b) Second inference: between the primary voltage and
The shape of graph on the display secondary voltage becomes bigger.
screen in steps 13 and 15 is the 4. A transformer can only change the
same. This shows continuous change voltage of an alternating current if the
in the direction of the current flow number of turns of the primary coil
and the voltage of the alternating and secondary coil is different. On
current irrespective of the type of the contrary, if the number of turns in
terminal connection to the C.R.O.. the primary and secondary coil in a
6. (a) Direct current transformer is the same, then there is
(b) Alternating current and direct current no change in the primary voltage and
secondary voltage.
14
Formative Practice 6.2 (p. 183)
1. A transformer is a device that changes

the voltage of an alternating current.

2. (a) alternating 4. (a) Damaged wire insulator. Exposed
(b) more live wire touches the exposed neutral
(c) step-up wire.
(d) step-down
(b) (i) Excessive load
3. (a) Microwave oven, washing machine, (ii) Fire. Large flow of current causes
refrigerator, television wires, plugs and sockets to
become so hot that they burn.
(b) Mobile phone charger, laptop/tablet
charger

4. (a) Vp = Np Brain Teaser (p. 199)
Vs Ns Can be used in Thailand but the time taken
to boil water is longer.
240 Np
5 = 10

Np = 10 × 240 Brain Teaser (p. 201)
5 No. A green building uses the concept
of savings on energy, water and material
= 480 consumption.

Number of turns in primary coil,

Np = 480 Formative Practice 6.4 (p. 202)
(b) The transformer in the mobile phone 1. Energy efficiency is the percentage of

charger is a step-down transformer energy input converted into useful energy
output.
because: 2. (a) Using the formula:

i) the output voltage is lower than

the input voltage.

ii) the number of turns in the P= E
t
secondary coils, Ns, is less
than the number of turns in the P = 180 kJ
2 minutes
primary coils, Np (Ns < Np).

Brain Teaser (p. 187) = 180 000 J
In one cycle, single-phase wiring has two 120 s
peaks whereas three-phase wiring has six
peaks. Because of this, the current supply of = 1 500 W
three-phase wiring is more stable. (b) Power of air conditioner,

P = 1 500 W

= 1 500 kW
1 000
Brain Teaser (p. 192)
Because most electric kettles sold in the = 1.5 kW
market use 10 – 12 A current. 3. P = VI

1 200 W = 240 V × I

Formative Practice 6.3 (p. 194) Electric current, I = 1 200 W
1. (a) Step-up transformer station 240 V

(b) Switch zone =5A
(c) Step-down transformer
2. (a) increased 4. (a) E = Pt
(b) National Grid Network
(c) Switch zone = 800 kW × 30 h
3. (a) Fuse, earth wire, circuit breaker, 1 000 60

lightning conductor (any three) = 0.4 kWh
(b) Fuse functions as a safety
(b) Cost of energy used by rice cooker
component that melts and cuts
off electric current supply when = Electrical energy used in kWh ×
excessive current flows through it. cost of energy for each kWh

= 0.4 kWh × 30 sen/kWh
= 12 sen

15

5. (a) Star rating labelling on an electrical replacing the burnt fuse wire with
appliance shows the energy
efficiency of the electrical appliance. a new fuse wire.

(b) At least 3 stars. The more stars on a An MCB is an electromagnetic
star rating label means more energy
savings. switch connected to the live

wire. An MCB cuts the circuit by

turning off its switch when the

current flowing through it exceeds

Summative Practice 6 (pp. 204 – 207) its limit. The MCB can be
1. (a) True
reused by turning on the switch
(b) False
(c) True again without having to do any
2. (a) Non-renewable energy source
(b) Renewable energy source replacement.
(c) Renewable energy source
(d) Renewable energy source (c) Using the formula:
3. (a) Magnetic field lines are cut
(b) Induced current P = VI
(c) LED lights up. Induced current flows
700 W = 240 V × I
through the LED. The flow of current
through the LED causes the LED to Electric current, I = 700 W
light up. 240 V
(d) Generator
4. (a) Cathode ray oscilloscope = 2.9 A
(b) Shape of graph, direction of current Fuse chosen is a 3 A fuse because
and voltage changes for direct the value of the fuse is slightly higher
current and alternating current. than the value of the electric current
(c) (i) Alternating current flowing through the hair dryer.
(ii) Direct current 7. (a) Using the formula:
5. (a) Step-down transformer
(b) Number of turns in the primary coil is Electric
more than the number of turns in the Power (W) = Voltage (V) × current
secondary coil.
(c) To reduce eddy current and increase (A)
the efficiency of the transformer = 230 V × 10 A
= 2 300 W

= 2 300 kW
1 000

(d) Using the formula, Vp = Np = 2.3 kW
Vs Ns (b) 13 A fuse.

10 = 100 13 A fuse is the most suitable
Vs 20 because a 13 A fuse allows a 10 A
current to flow through it but does
Secondary voltage, Vs = 10 × 20 not allow a current exceeding 13 A
100 to flow through the electric heater. A
current that is too high will damage
=2V the electric heater.
(c) A 10 A current that flows through 1A,
6. (a) Main fuse 2A, 3A and 5A fuses will melt the
fuse wires. Hence, the electric heater
(b) (i) Fuse and MCB function as safety will not be able to function.
15 A and 30 A fuses allow current
devices that protect appliance which is much greater than 10 A to
flow through the electric heater. This
from any excessive current flow. will damage the electric heater.
10 A fuse is also not suitable
(ii) When the current flowing through because most 10 A fuses normally
allow maximum current of less than
a fuse exceeds the value of 10 A to flow through it. Hence, the

the fuse, the fuse will melt

and cannot be reused without

16

10 A fuse will blow if installed in the MCB Model of MCB
electric heater.
8. (a) An MCB is a small electromagnetic The iron The iron nail
switch connected to the live wire. rotates in an rotates in an
(b) An MCB functions as an electric anti-clockwise anti-clockwise
safety device. An MCB cuts off the direction at the direction at the
circuit when the current flowing fulcrum. fulcrum on the
through it is too high or exceeds its ice cream stick.
limit value.
(c)

Ice cream Plastic rod The rotating The rotating
Plasticine stick iron pushes the iron nail pushes
spring upwards. the toothpick
Nail Finally, the upwards. Finally,
spring is the toothpick is
released and released and it
it is below the is below the iron
iron. nail.

Fulcrum

Copper Plastic Reset button When the plastic
wire Shoe Rubber toothpick when pushed rod is pushed
downwards will downwards,
box eraser push the iron it will push
downwards the iron nail
Contact – plasticine until the iron downwards until
Iron – nail nail is below the iron nail
Fulcrum – an ice cream stick the spring is below the
Reset button – plastic rod again. toothpick again.
Spring – plastic toothpick
Iron core – Rubber eraser CHAPTER 7 Energy and Power
Electric wire – copper wire Brain Teaser (p. 210)

Scenario: When the electric current (a) 1 000 (or 103) J
that flows through the MCB (b) 1 000 000 (or 106) J
exceeds its limit value, the
solenoid becomes a strong Brain Teaser (p. 212)
electromagnet. No

MCB Model of MCB Activity 7.1 (pp. 214, 215)
Questions
Electric Copper wire that 1. (a) Frictional force
wire that is is mounted to
mounted to the the plasticine (b) Gravitational force
contact and and iron 2. Student’s answer
iron is pulled nail is.pulled 3. Force, displacement in the direction of
downwards as downwards as
shown in shown in the the force, time
Figure 4. above diagram. 4. Student’s answer
5. (a) Aeroplane that is taking off, moving

ERL train.
(b) Sleep, sit

17

Formative Practice 7.1 (p. 215) 4. (a) Kinetic energy = 1 mv2
2
1. (a) Work is defined as the product where m is mass

of force and displacement in the v is velocity

direction of the force. Even though the value of the velocity,

(b) Joule v of a heavy vehicle is small, the

2. Energy is the ability to do work. value of its mass, m is big. Hence,

3. (a) Power is defined as the rate of doing the large mass of these heavy

work. vehicles causes more kinetic

(b) Watt energy.

4. (a) W = Fs (b) (i) Bullet fired from a pistol.

= 2 500 N × 4 m (ii) Aeroplane taking off from runway
= 10 000 J
at airport.
(b) Energy used = work done

= 10 000 J

(c) Power of crane, P = W Formative Practice 7.3 (p. 226)
t
10 000 J 1. The Principle of Conservation of Energy
= 1.2 minutes
states that energy cannot be created or

= 10 000 J destroyed but can only be converted from
72 s
one form to another.

= 138.89 W 2. (a) P, R

(b) Q

Formative Practice 7.2 (p. 221) 3. (a) Gravitational potential energy

1. (a) Gravitational potential energy is = mgh
= 2 kg × 10 m s–2 × 2.5 m
the work done to lift an object to a
= 50 J
height, h, from the surface of the
(b) According to the Principle of
Earth.
Conservation of Energy,
(b) Elastic potential energy is the work
Kinetic = Gravitational
done to compress or stretch an energy potential energy

elastic material over a displacement, 1
2
x from the position of equilibrium. mv2 = 50 J

2. (a) W = Fs

= 40 N × 0.5 m 1 × 2 kg × v2 = 50 J
2
= 20 J

(b) Gravitational potential energy v2 = 50 m2s–2

(c) Gravitational potential energy of ͱv = 50 m2s–2

possessed by the chair = work done = 7.07 m s–1

on it

= 20 J

3. Distance of compression of spring Summative Practice 7 (pp. 228, 229)
1. (a) Energy possessed by an object is
= original length – length of spring
of spring compressed due to its position or condition.
(b) Energy possessed by a moving
= 50 cm – 30 cm
object.
= 20 cm 2. (a) N m

= 0.2 m (b) Work
(c) stationary
Elastic potential energy (d) can
(e) acceleration
= 1 Fx 3. (a) W = Fs
2

= 1 (20 N) (0.2 m)
2

=2J

18

= 5 kg × 10 m s–2 × 2 m Explanation: This model of a roller
coaster has vertical, winding
= 100 J and turning loops.

(b) Energy used by motor = work done CHAPTER 8 Radioactivity

= 100 J Brain Teaser (p. 235)
(a) 1 Ci = 3.7 × 1010 Bq
4. (a) Gravitational potential energy = mgh (b) 1 Bq = 2.70 × 10−11 Ci

where m is the object mass Formative Practice 8.1 (p. 237)
1. (a) Wilhelm Roentgen
g is the gravitational acceleration
(b) Henri Becquerel
h is the height (c) Marie and Pierre Curie
2. Radioactivity is the spontaneous decay
(b) Elastic potential energy = 1 Fx, process of an unstable nucleus by
2 emitting radioactive radiation.
3. (a) curie (Ci), becquerel (Bq)
where F is the compression or (b) The decay rate of an unstable

stretching force nucleus.
4. Carbon-14 (C-14), Radon-222 (Rn-222),
x is the displacement from
Thorium-232 (Th-232), Uranium-238
equilibrium position (U-238)
5. Half-life, T1 , is the time taken for the
(c) Kinetic energy = 1 mv2,
2 2
where m is the mass,
number of undecayed nuclei to be
v is the velocity reduced to half of its original value.

5. (a) Work = force × displacement Formative Practice 8.2 (p. 239)
1. According to Dalton’s Atomic Theory, an
= 200 N × 0.4 m
atom is the smallest particle and cannot
= 80 J be further divided.
2. (a) When an atom loses electrons.
(b) Elastic potential energy (b) When an atom gains electrons.
3. (a) Q and S. In Q and S, the number of
= 1 Fx
2 protons is more than the number of
electrons.
= 1 × 200 N × 0.4 m (b) R and T. In R and T, the number of
2 electrons is more than the number of
protons.
= 40 J (c) P. In P, the number of protons is the
same as the number of electrons.
(c) Because part of the work done is 4. (a) One electron is gained.
(b) The number of electrons in the ion
used to bend the bow. increases by one.
(c) Bromide ion, Br–
6. (a) Principle of Conservation of Energy
Brain Teaser (p. 243)
(b) Vertical displacement of 2.5 cm from 1 μSv/h is equivalent to 10–6 J of ionising
radiation energy absorbed by 1 kilogram of
position Y. living tissue in a time interval of 1 hour.

(c) Potential energy at X = mgh 19

= 40 kg × 10 m s–2 × 5 m
1 000 100

= 0.02 J
Potential energy at Y = 0 J, so
difference in potential energy
= (0.02 – 0) J
= 0.02 J
7. Retort

stand

Rubber hose

Formative Practice 8.3 (p. 246) 4. (a) Presence of radioactive substance or
1. (a) Ionising radiation is radiation that radioactive radiation.

produces positive and negative (b) Hospitals, atomic research centres,
ions while passing through the air. X-ray rooms.
Examples of ionising radiation: alpha
radiation, beta radiation, gamma ray (c) Alpha radiation. It has the lowest
and X-ray (any one) penetration power.
(b) Non-ionising is radiation that does
not produce ions while passing 5. (a) Lead (or aluminium)
through the air. (b) For lead:
Examples of non-ionising radiation: Advantage – Lead is an appropriate
light (visible), infrared, radio waves shield from all types of radioactive
2. (a) lower, higher radiation including gamma rays which
(b) higher, lower have high penetration power.
3. (a) Cosmic rays, background radiation Disadvantage – The high density of
(b) Nuclear accidents, nuclear tests, use lead makes the clothing too heavy.
of radioisotopes in medical field For aluminium:
4. (a) microSievert/hour (μSv/h) Advantage – The lower density of
(b) 1 Sv is 1 Joule of ionising radiation aluminium makes the clothing less
energy absorbed by 1 kilogram of heavy.
living tissue. Disadvantage – Aluminium is a less
(c) Radiation dose less than 0.2 μSv/h efficient shield from gamma rays
5. The higher an individual is from the which have high penetration power.
surface of Earth, the stronger the cosmic
rays received. Hence, an individual who Summative Practice 8 (pp. 252 – 254)
is in an aeroplane at a high altitude will 1. (a)
absorb more cosmic rays causing his
ionising radiation dose to exceed the (b) ×
safety level.
6. Ionising radiation dose received by the (c)
student = 0.01 mSv/h × 2 h × 5 2. Radioactive decay is a spontaneous

= 0.1 mSv process by which an unstable nucleus
emits radioactive radiation until the
Formative Practice 8.4 (p. 250) nucleus becomes more stable.
1. (a) Carbon-14 dating to determine the 3. sodium-24 (Na-24)

age of an ancient object. 4. 0 hours 5.2 hours 10.4 hours
(b) Cobalt-60 to treat cancer by killing 32 g 16 g 8g

cancer cells. 15.6 hours 20.8 hours
(c) Phosphorus-32 to determine the 4g 2g

absorption rate of phosphate Therefore the remaining mass of Pa-234
fertilisers in plants. after 20.8 hours is 2 g.
(d) Uranium-235 to build weapons such 5. (a) Ion formed is a positive ion because
as atomic bombs.
(e) β-radiation to monitor the thickness of Mg atom loses two electrons to form
metal sheets. Mg2+ ion.
2. (a) Gamma rays (b) Ion formed is a negative ion because F
(b) Gamma rays preserve food by killing atom gains one electron to form F– ion.
the bacteria in the preserved food. 6. (a) X-ray and gamma ray:
3. Boxes with thick lead walls can prevent • are ionising radiation
all types of radioactive radiation emitted • have high penetration power in air
by radioactive sources or radioactive • are electromagnetic waves
waste from escaping. (b) (i) Sample Y. This is because the

20 strawberry in sample Y is still in
good condition.

(ii) Gamma rays region in space surrounding Earth. It is
(iii) Gamma rays kill bacteria in food. a combination of the Earth's magnetic
(iv) Yes. This is because the field (as the main magnetic field) and the
magnetic field in the region in space.
radioactive radiation dose in 4. Solar wind
preserved food is within the 5. Comet
normal level or safe level.
7. (a) • Wear appropriate protective Formative Practice 9.2 (p. 265)
clothing. 1. Phenomena that occur on the surface of
• Detect radioactive radiation dose
found on clothing with detectors the Sun and in outer space.
such as Geiger Müller tube which 2. Formation of aurora, disturbances to
gives a warning sound if the dose
detected exceeds the normal level. telecommunication, navigation system
(b) and electric power lines
3. When the number of sunspots increases,
Light rays Light rays Mirror coronal mass ejections will increase.

Mirror Summative Practice 9 (pp. 266 – 267)
1. A: Convection zone
LED
LED B: Chromosphere
C: Photosphere
Empty mineral water D: Radiation zone
bottles wrapped E: Core
in newspaper F: Corona
2. 11 years
Explanation: 3. Sunspots
4. – Smartphone (mobile)
Component in Representing – Internet
the model component in – TV broadcast
– Global positioning system (GPS)
the system 5. All living things would die. Ionising
radiation in solar winds would reach
LED Beta radiation Earth and be absorbed by living things at
source levels exceeding the safety level. Hence,
the risks to the health of living things
Light rays Beta radiation would increase and this would be fatal.
6. Sketch of model: Student’s answer
Mineral water Bottles filled Explanation:
bottles wrapped with drinking – Green plastic bag represents ‘Bow
in newspaper water
Shock’
Mirror Beta radiation – White thread represents magnetic field
detector
lines from other planets
CHAPTER 9 Space Weather – Red thread represents Earth’s

Formative Practice 9.1 (p. 263) magnetic field
1. Photosphere, chromosphere, corona – Polystyrene cup represents a
2. Prominence, solar flare, coronal mass
protective layer, the magnetosphere
ejection – Convex cover represents the part of
3. Earth’s magnetosphere is defined as a
the magnetosphere that is directed
towards the Sun
– Plasticine represents Earth

21

CHAPTER 10 Space Exploration 2. (a) Ptolemy
(b) Kepler
Formative Practice 10.1 (p. 272)
1. (a) Geocentric model 3. Through human effort to obtain
rational explanation about objects and
(b) Heliocentric model phenomena in space based on their
(c) Modified heliocentric model according intellectual abilities.

to Kepler’s Law 4. Because space probes are not built to
2. (a) Similarity: In the Solar System return to Earth.

models built by Ptolemy 5. (a) To gather information about Saturn to
and Copernicus, Earth or be sent back to Earth.
the Sun revolve in orbits.
(b) Difference: In the Solar System (b) Solar wind
model built by Ptolemy, (c) Solar energy
Earth is at the centre of 6. (a) – Oversee conditions and usage of
the orbit whereas in the
Solar System model built land
by Copernicus, the Sun – Predict yield of crops
is at the centre of Earth’s (b) – Explore regions to search for oil
orbit.
3. (a) Similarity: The Solar System models and mineral sources
built by Copernicus and – Map Earth’s surface
Kepler are heliocentric (c) – Oversee natural disasters such as
models.
(b) Difference: In the Solar System model floods
built by Copernicus, Earth – Oversee forest fires, oil spills in
and the planets revolve in
circular orbits whereas in the oceans and landslides
the Solar System model (d) – Detect enemy invasions from air,
built by Kepler, Earth and
the planets revolve in land and sea
elliptical orbits. – Detect nuclear tests
7. (a) A rocket is an aircraft that obtains its
Formative Practice 10.2 (p. 276) thrust using a rocket engine.
1. Telescope (b) To send astronauts, spaceships,
2. (a) Discovery is a space shuttle. satellites, remote sensing instruments
and space probes to space.
(b) Hape is a rocket which sent (c) Functions as a weapon by carrying
Discovery to space. guided missiles.
8. Sketch of model: Student’s answer
3. (a) Remote sensing technology Explanation:
(b) To identify the locations hit by flood
and determine the places to transfer Material Function
flood victims Aluminium foil
Shield against
4. MACRES is responsible for all remote Cylindrical ionising radiations
sensing projects in Malaysia. cardboard from space
Black plastic
Summative Practice 10 (pp. 278 – 280) sheet As a rocket

1. (a) × Cardboard in Solar battery/
the form of a Source of energy
(b) spaceship for spaceship

(c) × As a spaceship
(d) ×

22

Answer

Only selected answers are provided here

CHAPTER 1 Stimuli and Responses Positive hydrotropism allows roots of plants
to grow towards water so that they can
Summative Practice 1 absorb water to enable plants to carry out
photosynthesis.
1. (a) × (b) (c) × (d)

2. P: Brain

Q: Spinal cord CHAPTER 2 Respiration

R: Peripheral nerve

3. (a) Changes in the size of the pupil of the eye. Summative Practice 2

(b) Intensity of light which enters the eye. 1. (a) Alveolus

(c) The lower the intensity of light directed (b) Bronchus

towards the eye, the larger the size of the pupil (c) Nasal cavity

of the eye. 2. P: Trachea

(d) During a solar eclipse, the bright rays of the Q: Bronchus

Sun will enter the eye and damage the cells of R: Alveolus

the retina. 3. (a) (b) (d)

4. (a) Sound Earlobe Ear canal 4. (a) higher (b) lower

5. (a) Haemoglobin transports oxygen from the red

Eardrum Ossicles blood cell to body cells.

Oval window Cochlea (b) Oxyhaemoglobin easily decomposes into

haemoglobin and oxygen when it reaches body

Auditory nerve Brain cells so that oxygen can diffuse into the cells.
(b) Light Cornea Aqueous humour
6. (a) Azura may be allergic to pollen. In Spring,

more pollen is released from anthers. When

Pupil Eye lens Vitreous humour Azura inhales air containing pollen, there is a

higher risk of her getting an asthma attack.

Retina Optic nerve Brain (b) Any place that is hazy and dusty. Examples:

5. (a) X: Touch receptor industrial areas, construction sites and others.
Y: Pain receptor
Haze and dust also cause asthma attacks in
(b) Fingertip is more sensitive towards touch
stimuli compared to the palm of the hand. asthma patients.
Fingertip has a thinner layer of epidermis and
more touch receptors compared to the palm of 7. (a) – Thickness of the wall
the hand.
– Moisture of the wall
(c) Agree. The tongue is a sensory organ that has
receptors known as taste buds on the surface – Surface area
of the tongue which is protected by skin
epidermis. – Network of capillaries

6. (a) The sense of smell helps us to detect danger (b) (i) Asthma
such as leakage of gas that might occur in
the science laboratory. For example, we can Symptom: Shortness of breath
detect the presence of dangerous gases such as
chlorine and ammonia from their smell. Cause: Excessive release of mucus

(b) Dogs have a very sensitive sense of smell on the surface of alveolus
because they have more sensory cells for smell
than human and are more efficient to analyse reduces the surface area and
smell than human.
rate of gaseous exchange in
7. (a) – Positive phototropism
– Positive hydrotropism the alveolus thereby causing

(b) Positive phototropism ensures shoots and shortness of breath.
leaves of plants obtain sufficient sunlight to
make food through photosynthesis. (ii) Bronchitis

Symptom: Shortness of breath

Cause: Inflammation of the

bronchus in bronchitis

patients caused by tar

and irritants in cigarette

smoke reduces the rate of

movement of air from the

nose to the lungs through

the bronchus. This causes

281

bronchitis patients to be Diastolic pressure reading is reading of blood
pressure which is lower when heart ventricle
frequently breathless. slackens to facilitate blood flowing from the
whole body back to the heart.
(iii) Emphysema 6. (a) (i) Eric, Roy
(ii) Blood will coagulate.The victim may die.
Symptom: Shortness of breath (b) (i) Individual 2.

Cause: The alveolus in emphysema This is because she fulfils the age
condition of 18 years and above but less
patients is damaged by than 60 years. She also fulfils the body
mass condition of more than 45 kg.
dangerous substances in (ii) Pregnant women are not suitable to
donate blood.
the air such as irritants in

cigarette smoke. Hence, the

surface area for gaseous

exchange in the alveolus is

reduced causing shortness

of breath.

8. – Stop smoking.

To avoid harmful substances found in cigarette CHAPTER 4 Reactivity of Metals

smoke from entering the lungs and harming the Summative Practice 4
1. (a) Elements: Iron, Silver, Potassium, Tin
respiratory system. Compounds: Quartz, Bauxite, Galena,
Hematite, Limestone
– Avoid places with polluted air. (b) Bauxite, Aluminium and oxygen
2. (a) Tin(IV) oxide
To avoid inhaling air that contains harmful (b) Carbon
(c) Tin + oxygen → Tin(IV) oxide
substances such as cigarette tar, carbon
3. (b) (c)
monoxide, sulphur dioxide, nitrogen dioxide, 4. (a) Oxygen

haze, dust and pollen which are harmful to the (b) Potassium and sodium are very reactive metals.
Paraffin prevents potassium and sodium from
respiratory system. reacting with oxygen and water vapour in the air.

– Have proper exercise and lead a healthy lifestyle. 5. (a) Oxygen
(b) To provide oxygen for the reaction.
To maintain a healthy respiratory system. (c) Heat the powdered metal until it glows before
heating potassium manganate(VII) to provide
CHAPTER 3: Transportation oxygen for the reaction.
(d) To construct a reactivity series of metals.
Summative Practice 3

1. (a) PULSE (d) PHLOEM

(b) TRANSPIRATION (e) HEART

(c) CAPILLARY (f) ANTIGEN

2. (a) (b) × (c) × (d) ×

3. (a) Valve

(b) Transport oxygenated blood

(c) (i) Blood vessel Q has thick walls to CHAPTER 5 Thermochemistry

withstand high blood pressure.

(ii) Blood vessel R has walls which are one Summative Practice 5

cell thick to increase the efficiency of 1. (a) Exothermic reaction

exchange of substances between blood (b) Endothermic reaction

and body cells through diffusion. (c) Exothermic reaction

4. (a) Oxygen, carbon dioxide, water, digested food, (d) Endothermic reaction

waste products (e) Exothermic reaction

(b) Oxygen, carbon dioxide, water (f) Exothermic reaction

(c) During the day, plant cells carry out 2. (a) released (c) hot

photosynthesis and produce oxygen. Hence, (b) increases (d) absorbed

plant cells do not need oxygen supply. 3. (a) THERMOCHEMISTRY

5. (a) (i) dub (b) PHOTOSYNTHESIS

(ii) lub (c) RESPIRATION

(iii) systolic (d) THERMOMETER

(iv) diastolic (e) ENDOTHERMIC

(b) Systolic pressure reading is higher than diastolic (f) EXOTHERMIC

pressure reading. Systolic pressure reading is 4. Heating of calcium carbonate is an endothermic

reading of blood pressure which is higher when reaction. Heat is absorbed by the chemical reaction

heart ventricle contracts to force blood out of that occurs during the decomposition of calcium

the heart to be distributed to the whole body. carbonate.

282

5. The reaction between hydrochloric acid and sodium (b) Elastic potential energy = 1 Fx,
carbonate is an exothermic reaction whereas the 2
reaction between hydrochloric acid and sodium
hydrogen carbonate is an endothermic reaction. where F is the compression or stretching force

x is the displacement from equilibrium

position

CHAPTER 6 Electricity and Magnetism (c) Kinetic energy = 1 mv2,
2
Summative Practice 6
where m is the mass

1. (a) True (b) False (c) True v is the velocity

2. (a) Non-renewable energy source

(b) Renewable energy source CHAPTER 8 Radioactivity

(c) Renewable energy source

(d) Renewable energy source Summative Practice 8

3. (a) Magnetic field lines are cut 1. (a) (b) × (c)

(b) Induced current 2. Radioactive decay is a spontaneous process by

(c) LED lights up. Induced current flows through which an unstable nucleus emits radioactive

the LED. The flow of current through the LED radiation until the nucleus becomes more stable.

causes the LED to light up. 3. sodium-24 (Na-24)

(d) Generator 4. 0 hours 5.2 hours 10.4 hours

4. (a) Cathode Ray Oscilloscope 32 g 16 g 8g

(b) Shape of graph, direction of current and 15.6 hours 20.8 hours
4g 2g
voltage changes for direct current and

alternating current.

(c) (i) Alternating current Therefore the remaining mass of Pa-234 after
20.8 hours is 2 g.
(ii) Direct current

5. (a) Step-down transformer

(b) Number of turns in the primary coil is more CHAPTER 9 Space Weather

than the number of turns in the secondary

coil. Summative Practice 9

(c) To reduce eddy current and increase the 1. A: Convection zone D: Radiation zone

efficiency of the transformer B: Chromosphere E: Core

(d) Using the formula, Vp = Np C: Photosphere F: Corona
Vs Ns
2. 11 years

10 V 100 turns 3. Sunspots
Vs 20 turns
= 4. – Smartphone (mobile)

20 turns – Internet
100 turns
Secondary voltage, Vs = 10 V × – TV broadcast

= 2V – Global positioning system (GPS)

CHAPTER 7 Energy and Power CHAPTER 10 Space Exploration

Summative Practice 7 Summative Practice 10

1. (a) Energy possessed by an object is due to its 1. (a) × (b) (c) × (d) ×

position or condition. 2. (a) Ptolemy (b) Kepler

(b) Energy possessed by a moving object. 3. Student's answers

2. (a) N m (b) Work 4. Because space probes are not built to return to

(c) stationary (d) can Earth.

(e) acceleration 5. (a) To gather information about Saturn to be sent

3. (a) W = Fs back to Earth.

= 5 kg × 10 m s-2 × 2 m (b) Solar wind

= 100 J (c) Solar energy

(b) Energy used by motor = work done

= 100 J Complete answers
for teachers
4. (a) Gravitational potential energy = mgh http://links.and l17.
com/BT_Science_283
where m is the object mass
283
g is the gravitational acceleration

h is the height

Glossary

Alternating current An electric current with the direction of its flow constantly changing.

Artery A type of blood vessel which transports oxygenated blood from the heart to the whole
body.

Aurora A stunning light display in the sky when charged gas particles interact with atoms and
molecules in Earth’s atmosphere.

Capillary A type of blood vessel which connects arteries with veins.

Carboxyhaemoglobin A stable compound formed when carbon monoxide combines
chemically with haemoglobin.

Cathode Ray Oscilloscope (C.R.O.) An electronic device that can be used to show the
differences in the shape of graph, direction of current and voltage change for direct current and
alternating current.

Coronal mass ejection A huge cloud of plasma that erupts from the Sun and often occurs
together with huge and strong solar flares.

Direct current An electric current that flows only in one direction.

Earth’s magnetosphere A region in outer space surrounding Earth where the magnetic field in
Earth’s magnetosphere is a combination of Earth’s magnetic field and the magnetic field in the
region in space.

Electric current Rate of flow of electric charges through a conductor.

Electric meter A device used to measure the quantity of electrical energy used.

Energy The ability to do work.

Energy efficiency Percentage of energy input that is converted to useful form of energy output.

Exudation (guttation) Process of water loss from plants in liquid form through hydathodes
found at the edges of leaves.

Fuse A short, fine wire, heats up easily and melts when the current flowing through it exceeds
the value of the fuse.

Generator A device used to generate electrical energy in the form of an induced current.

Geocentric model Solar System Model with Earth at the centre and the Sun revolving
around Earth.

Geotropism Directional response of plants towards the force of gravity.

284

Green building A building which applies the concept of energy conservation to save the cost of
energy consumption and reduce the release of carbon dioxide.

Heliocentric model Solar System Model with the Sun at the centre and Earth and other planets
revolving around the Sun.

Hydrotropism Directional response of plants towards water.

Involuntary action Action that occurs immediately without conscious control or prior thoughts.

Kinetic energy Energy possessed by a moving object with a given mass.

Long-sightedness A type of visual defect which causes near objects to appear blurry because
the images are focused behind the retina.

Metal extraction Process of obtaining a metal from its ore.

Mineral Solid element or compound present naturally with definite crystalline structure and
chemical composition.

Nastic response Response towards stimulus such as touch but does not depend on the direction
of the stimulus.

Non-renewable energy sources Energy sources that cannot be replaced and will deplete.

Optical illusion An object that is seen differs from its actual state.

Oxyhaemoglobin Unstable compound formed when oxygen combines chemically with
haemoglobin in the blood.

Passive smoker A person who does not smoke but inhales cigarette smoke from nearby
smokers.

Phloem Component in vascular bundle which transports sucrose produced during
photosynthesis to other parts of the plant.

Phototropism Directional response of plants towards light.

Power Rate of doing work.

Prominence Huge loop or arched column of glowing gases over the sunspot.

Pulse Produced by the contraction and relaxation of the muscular artery wall.

Reactivity series of metals Arrangement of metals according to their reactivity with oxygen.

Remote sensing Method of gathering and recording information from a distance.

Renewable energy sources Energy sources that can be replaced continually and will
never deplete.

Short-sightedness A type of visual defect which causes distant objects to appear blurry because
the images are focused in front of the retina.

285

Solar cycle The activity of sunspot that seems to appear and disappear according to a 11-year
cycle.
Solar wind Particles in plasma such as electrons, protons and alpha particles that erupt from
the Sun to outer space travelling together at high speeds.
Space probe Spacecraft that gathers information and sends the information back to
the Earth.
Space weather Phenomena that occur on the surface of the Sun (such as prominences, solar
flares, sunspots and coronal mass ejections) and in space (such as solar winds, solar radiation
storms and geomagnetic storms).
Sunspots Dark regions seen on the surface of the Sun.
Thermochemistry A study associated with heat changes during chemical reactions.
Thigmotropism Directional response of plants towards touch.
Transformer Device that changes the voltage of an alternating current.
Transpiration Process of water loss in the form of water vapour from the surface of plants to
the air through evaporation.
Tropism Directional response of plants towards stimuli such as light, water, gravity and touch
from a certain direction.
Value of fuse Maximum value of current that can flow through the fuse without causing the
fuse wire to melt.
Vein A type of blood vessel which transports deoxygenated blood from the whole body to the
heart.
Voltage Electrical energy used to move a unit of electric charge through a conductor.
Voluntary action Conscious action and conducted under one’s will.
Xylem Component in vascular bundle which transports water and dissolved mineral salts from
the roots to the leaves.

286

Reference

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Gareth Williams (2011). New Biology for You, Updated, United Kingdom: Nelson Thornes

Gary Philpott and Jennifer Clifford (2009). Longman Physics 11-14 (2009 edition),
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Ian J. Burton (2015). Cambridge O Level Biology Revision Guide, 2nd Revision, United Kingdom:
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Joanne Baker (2010). 50 ideas universe, United Kingdom: Quercus Editions Ltd, London.

Karen C. Timberlake (2018). Chemistry – An introduction to General, Organic and Biological
Chemistry, 13th Edition, United States: Pearson.

Keith Johnson (2011). New Physics for You, Updated, United Kingdom: Nelson Thornes.

Lawrie Ryan (2011). New Chemistry for You, Updated, United Kingdom: Oxford Longman,
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Tingkatan 3, Malaysia: Pustaka Sistem Pelajaran Sdn. Bhd.

Phillipa Gardom Hulme (2013). Complete Chemistry for Cambridge, United Kingdom: Oxford
University Press.

Stephen Schneider and Thomas Arny (2015). Pathways to Astronomy, United States: Glencoe
Science Mc-Graw Hill.

Tho Lai Hoong (1990). Fakta Penting Fizik Moden SPM, Malaysia: Penerbit Fajar Bakti Sdn. Bhd.

Tho Lai Hoong (1991). Fizik Tingkatan 4 KBSM, Malaysia: Didika Sdn. Bhd.

Tho Lai Hoong (1996). Pure Physics Modern Certificate Guides, Singapore: Oxford University
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Tho Lai Hoong, Hasnah binti Abu Samah (2012). Sains Tingkatan 3, Malaysia: Sasbadi Sdn. Bhd.

287

Index

Alternating current 161, 170 – 172, Geocentric 269 – 270, 284 Principle of conservation of
177, 180, 183 – 186, 194, 199, Geochronology 231, 247, energy 208 – 209, 222 – 223,
203 – 204, 283 – 284, 286 225 – 228
249 – 251
Alveolus 45 – 47, 53 – 56, 64, 73, Geotropism 3, 31 – 32, 34 – 35, Prominence 257, 259 – 260, 263,
75 – 76, 281 – 282 265, 285
40, 284
Antibody 79, 98 Gravitational potential energy 168, Pulmonary circulatory system 89
Antigen 79, 98 – 99, 282 Radiation zone 257 – 258,
Artery 79, 83, 85 – 91, 95, 208 – 209, 216- 217, 221 – 223,
226 – 229, 283 265 – 266, 283
113, 117, 284 – 285 Guard cell 45, 68 – 70, 103 Radioactive decay 231, 234 – 235,
Astigmatism 26, 27, 29 Heart 8, 10, 27, 55, 79 – 81,
Becquerel (Bq) 231, 233, 235, 83 – 90, 93 – 95, 113 – 117, 119, 252, 283
209, 282, 284 Radioactive substance 159, 231,
251 – 252 Heliocentric 269 – 271, 285
Blood clot 79, 248 Human nervous system 2, 4 – 5, 235 – 237, 243, 245, 248 – 251,
Blood vessel 65, 81, 83 – 85, 88, 10, 40 – 42 252, 254
Hydrotropism 3, 32 – 33, 35, 40, Reactivity Series of Metals 121 – 123,
115 – 117, 282, 284 281, 285 129, 132 – 137, 143, 145, 282,
Capillary 54, 79, 88, 95, 113, 282, Induced current 161, 164, 166, 180, 285
203, 283 – 284 Remote sensing 268 – 269,
284 Involuntary action 3, 6 – 10, 275 – 279, 285
Carboxyhaemoglobin 58, 284 40 – 41, 285 Renewable energy source 160,
Cathode Ray Oscilloscope (C.R.O.) Ionising power 231, 233, 162 – 163, 167, 176, 201, 203,
240 – 241, 246 205, 283, 286
171 – 172, 176, 283, 284 Kepler’s Law 269, 271 Satellite 255, 269, 273, 275 – 277
Cell respiration 45, 81 Kinetic energy 167 – 169, 208 – Secondary coil 161, 177 – 183,
Centrifugation 96 209, 216, 220 – 229, 283, 285 206, 283
Chromosphere 257 – 258, 265, 283 Magnetosphere 257, 261 – 263, Solar cycle 257, 259, 264 – 266, 286
Convection zone 257 – 259, 265, 265 – 267, 284 Solar flare 257, 259 – 260, 263 – 264,
Mineral 33, 82, 109, 112, 114, 275, 284 – 285
266, 283 122 – 126, 128, 135, 140, Solar wind 257, 259, 261 – 265,
Corona 231, 257 – 260, 263 – 266, 142 – 145, 254, 275, 285 – 286 267, 283, 285 – 286
Monocular vision 3, 36 – 38, 40 Space probe 269, 275 – 277, 279,
283, 285 Nastic movement 3, 30, 34 – 35, 40 283, 286
Coronal mass ejection 257, National Grid Network 161, Space telescope 269, 273 – 274, 278
184 – 186, 194, 203 Stereophonic hearing 3, 37 – 39
259 – 260, 263 – 265, 284 – 285, Non-renewable energy source 160, Stereoscopic vision 3, 36 – 37, 40
288 162 – 163, 167, 176, 203, 205, Stomatal pore 69 – 70, 103
Curie (Ci) 231 – 233, 235, 245, 283, 285 Sunspot 257, 259 – 260, 263 – 265,
250 – 252 Optical illusion 3, 24, 29, 285 283, 285
Dalton’s Atomic Theory 231, Oxyhaemoglobin 45, 55 – 56, 58, Systemic circulatory system 89, 116
238 – 239 73, 76 Taste bud 3, 15
Direct current 161, 166, 170 – 172, Passive smoker 62– 63, 285 Thermal equilibrium 147, 149
203 – 204 Peripheral nerve 3 Thigmotropism 3, 34 – 35, 40, 286
Earth wire 161, 188 – 192, 193, 204 Phloem 68, 79, 81, 103, 109, Transpiration 78 – 79, 102 – 109,
Earth’s crust 123 – 125, 137, 110 – 114, 282, 285 112, 115, 119 – 120, 282, 286
142 – 144 Photosphere 257 – 259, 265 – 266, Umami 15, 21 – 22
Effector 3, 6, 8 283 Vascular bundle 109, 112,
Elastic potential energy 208 – 209, Phototropism 30 – 31, 33, 35, 40, 114 – 115, 285 – 286
218 – 219, 221 – 222, 224, 281, 285 Vein 79, 83, 85 – 89, 95, 113 – 114,
226 – 228 Primary coil 161, 177 – 180, 284, 286
Elliptic 271, 277, 279 182 – 183, 206 Voluntary action 3, 6 – 10, 40 – 41,
Endothermic reaction 146 – 149, 285
151 – 157 Xylem 68, 79, 81, 103, 109 – 110,
Exothermic reaction 147 – 149, 112 – 114
151 – 157, 282 – 283
Extraction of metal 122 – 123,
136 – 137, 143, 145
Exudation (Guttation) 103 – 104,
284

288