Science F3

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 Instant cold pack:
the decomposition of calcium carbonate. – Use toothpick to prick a hole in the
5. The reaction between hydrochloric acid small plastic bag so that water flows
and sodium carbonate is an exothermic out from the plastic bag and mixes
reaction whereas the reaction between with the ammonium nitrate powder in
hydrochloric acid and sodium hydrogen the large plastic bag.
carbonate is an endothermic reaction. – 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
drop. CHAPTER 6 Electricity and
7. (a) Thermite reaction is an exothermic Magnetism
reaction because heat is released
into the surroundings. Activity 6.1 (p. 165)
(b) In a thermite reaction, heating Questions
of iron(II) oxide, aluminium and 1. Electric current
magnesium tape produces iron and 2. Cutting of magnetic field lines (by copper
carbon dioxide through an exothermic wire or coil of wire)
reaction. The heat released in this 3. Induced current
reaction increases the temperature of
the iron and carbon dioxide until the Activity 6.2 (p. 166)
iron melts. This molten iron is used to Questions
repair and reconnect the broken iron 1. (b)
railway rails. (c)
8. 2. Induced current is detected based on the
lighting up of the LED. Induced current
Large plastic
bag is produced and flows through the LED.
Therefore the LED lights up.
Toothpick
3. Current is induced when magnetic field
lines are cut.
Small plastic 4. Sound energy, heat energy, light energy
bag 5. – LED lasts longer and does not burn
Water out easily
– LED will light up when electric current
Calcium chloride flows through as compared to filament
or ammonium bulb which only lights up when its
nitrate powder filament is hot enough.
Instant hot pack:
– Use toothpick to prick a hole in the Activity 6.4 (pp. 172 – 175)
small plastic bag so that water flows Questions
out from the plastic bag and mixes 1. To show the shape of graph, direction
with the calcium chloride powder in the of current and voltage change for direct
large plastic bag. current and alternating current.
– Dissolving of calcium chloride in water 2. Similarity: Magnitude of the
is an exothermic reaction which heats displacement of the light
up the large plastic bag. spot from the zero position
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 sources that can be replaced continually
fixed and of the same value. and will not deplete while non-renewable
Difference: Displacement of the light energy sources are energy sources that
spot from the zero position cannot be replaced and will deplete.
in step 6 is positive while 2. (a) LED lights up in arrangements P
displacement of the light spot and Q. In arrangements P and Q,
from the zero position in step magnetic field lines are cut by the
8 is negative. This shows that coil of wire to produce induced
the current in step 6 flows current. This induced current flows
from positive to negative through the LED causing the LED to
whereas in step 8 the flow light up.
of current in the C.R.O. has (b) LED does not light up in arrangement
been reversed. R. In arrangement R, there is no
3. (a) First inference: cutting of magnetic field lines and
The different position of the straight no induced current flows through the
line on the display screen in steps LED.
7 and 9 shows that direct current is 3. To show the shape of graph, direction
the electric current which flows in the of current and voltage change for direct
opposite direction. current and alternating current.
(b) Second inference:
The position of the straight line from Experiment 6.1 (pp. 178 – 180)
the zero position in steps 7 and 9 Questions
which are different shows that direct 1. (a) Bulb P is brighter compared to
current in steps 7 and 9 flow in the bulb S.
opposite directions. (b) V > V S
p
4. Voltage produced by the power supply (c) Step-down transformer
keeps changing. Hence, the light spot 2. (a) Bulb S is brighter compared to
on the screen moves up and down to bulb P.
produce a vertical trace on the screen (b) V < V S
p
irrespective of the type of terminal (c) Step-up transformer
connection to the C.R.O. 3. If the difference between the number
5. (a) First inference: of turns in the primary coil and the
The shape of graph on the display number of turns in the secondary coil in
screen produced by the vertical and a transformer is increased, the difference
horizontal trace made by a light between the primary voltage and
spot shows continuous change in secondary voltage becomes bigger.
the direction of current flow and the 4. A transformer can only change the
voltage of the alternating current. voltage of an alternating current if the
(b) Second inference: number of turns of the primary coil
The shape of graph on the display and secondary coil is different. On
screen in steps 13 and 15 is the the contrary, if the number of turns in
same. This shows continuous change the primary and secondary coil in a
in the direction of the current flow transformer is the same, then there is
and the voltage of the alternating no change in the primary voltage and
current irrespective of the type of secondary voltage.
terminal connection to the C.R.O..
6. (a) Direct current Formative Practice 6.2 (p. 183)
(b) Alternating current and direct current 1. A transformer is a device that changes
the voltage of an alternating current.
14

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
(b) Mobile phone charger, laptop/tablet become so hot that they burn.
charger
V p N p Brain Teaser (p. 199)
4. (a) =
V s N s Can be used in Thailand but the time taken
240 N p to boil water is longer.
=
5 10
240 Brain Teaser (p. 201)
N = 10 × 5 No. A green building uses the concept
p
= 480 of savings on energy, water and material
Number of turns in primary coil, consumption.
N = 480
p
(b) The transformer in the mobile phone Formative Practice 6.4 (p. 202)
charger is a step-down transformer 1. Energy efficiency is the percentage of
because: energy input converted into useful energy
i) the output voltage is lower than output.
the input voltage. 2. (a) Using the formula:
ii) the number of turns in the E
secondary coils, N , is less P = t
s
than the number of turns in the 180 kJ
primary coils, N (N < N ). P = 2 minutes
s
p
p
180 000 J
Brain Teaser (p. 187) = 120 s
In one cycle, single-phase wiring has two
peaks whereas three-phase wiring has six = 1 500 W
peaks. Because of this, the current supply of (b) Power of air conditioner,
three-phase wiring is more stable. P = 1 500 W
1 500
= kW
Brain Teaser (p. 192) 1 000
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 = 5 A
(c) Step-down transformer 4. (a) E = Pt
2. (a) increased
(b) National Grid Network = 800 kW × 30 h
(c) Switch zone 1 000 60
3. (a) Fuse, earth wire, circuit breaker, = 0.4 kWh
lightning conductor (any three) (b) Cost of energy used by rice cooker
(b) Fuse functions as a safety = Electrical energy used in kWh ×
component that melts and cuts cost of energy for each kWh
off electric current supply when = 0.4 kWh × 30 sen/kWh
excessive current flows through it. = 12 sen
15

5. (a) Star rating labelling on an electrical replacing the burnt fuse wire with
appliance shows the energy a new fuse wire.
efficiency of the electrical appliance. An MCB is an electromagnetic
(b) At least 3 stars. The more stars on a switch connected to the live
star rating label means more energy wire. An MCB cuts the circuit by
savings. turning off its switch when the
current flowing through it exceeds
its limit. The MCB can be
Summative Practice 6 (pp. 204 – 207) reused by turning on the switch
1. (a) True again without having to do any
(b) False replacement.
(c) True (c) Using the formula:
2. (a) Non-renewable energy source P = VI
(b) Renewable energy source 700 W = 240 V × I
(c) Renewable energy source
(d) Renewable energy source Electric current, I = 700 W
3. (a) Magnetic field lines are cut 240 V
(b) Induced current = 2.9 A
(c) LED lights up. Induced current flows Fuse chosen is a 3 A fuse because
through the LED. The flow of current the value of the fuse is slightly higher
through the LED causes the LED to than the value of the electric current
light up. flowing through the hair dryer.
(d) Generator 7. (a) Using the formula:
4. (a) Cathode ray oscilloscope Electric
(b) Shape of graph, direction of current Power (W) = Voltage (V) × current
and voltage changes for direct (A)
current and alternating current. = 230 V × 10 A
(c) (i) Alternating current = 2 300 W
(ii) Direct current 2 300
5. (a) Step-down transformer = 1 000 kW
(b) Number of turns in the primary coil is = 2.3 kW
more than the number of turns in the (b) 13 A fuse.
secondary coil. 13 A fuse is the most suitable
(c) To reduce eddy current and increase because a 13 A fuse allows a 10 A
the efficiency of the transformer current to flow through it but does
V p N p not allow a current exceeding 13 A
(d) Using the formula, =
V s N s to flow through the electric heater. A
current that is too high will damage
10 100
= the electric heater.
V s 20 (c) A 10 A current that flows through 1A,
20 2A, 3A and 5A fuses will melt the
Secondary voltage, V = 10 × 100 fuse wires. Hence, the electric heater
s
= 2 V will not be able to function.
6. (a) Main fuse 15 A and 30 A fuses allow current
(b) (i) Fuse and MCB function as safety which is much greater than 10 A to
devices that protect appliance flow through the electric heater. This
from any excessive current flow. will damage the electric heater.
(ii) When the current flowing through 10 A fuse is also not suitable
a fuse exceeds the value of because most 10 A fuses normally
the fuse, the fuse will melt allow maximum current of less than
and cannot be reused without 10 A to flow through it. Hence, the

16

10 A fuse will blow if installed in the
electric heater. MCB Model of MCB
8. (a) An MCB is a small electromagnetic
switch connected to the live wire. The iron The iron nail
(b) An MCB functions as an electric rotates in an rotates in an
safety device. An MCB cuts off the anti-clockwise anti-clockwise
circuit when the current flowing direction at the direction at the
through it is too high or exceeds its fulcrum. fulcrum on the
limit value. ice cream stick.
(c)
The rotating The rotating
Ice cream Plastic rod iron pushes the iron nail pushes
Plasticine stick spring upwards. the toothpick
Finally, the upwards. Finally,
Nail
spring is the toothpick is
released and released and it
it is below the is below the iron
iron. nail.
Fulcrum
Reset button When the plastic
when pushed rod is pushed
downwards will downwards,
Copper
wire Shoe Rubber Plastic push the iron it will push
box eraser toothpick downwards the iron nail
until the iron downwards until
nail is below the iron nail
Contact – plasticine the spring is below the
Iron – nail again. toothpick again.
Fulcrum – an ice cream stick
Reset button – plastic rod
Spring – plastic toothpick
Iron core – Rubber eraser CHAPTER 7 Energy and Power
Electric wire – copper wire Brain Teaser (p. 210)
3
Scenario: When the electric current (a) 1 000 (or 10 ) J
6
that flows through the MCB (b) 1 000 000 (or 10 ) 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 (b) Gravitational force
mounted to the the plasticine 2. Student’s answer
contact and and iron 3. Force, displacement in the direction of
iron is pulled nail is.pulled the force, time
downwards as downwards as 4. Student’s answer
shown in shown in the 5. (a) Aeroplane that is taking off, moving
Figure 4. above diagram. ERL train.
(b) Sleep, sit

17

1
Formative Practice 7.1 (p. 215) 4. (a) Kinetic energy = mv 2
1. (a) Work is defined as the product 2
of force and displacement in the where m is mass
direction of the force. v is velocity
(b) Joule Even though the value of the velocity,
2. Energy is the ability to do work. v of a heavy vehicle is small, the
3. (a) Power is defined as the rate of doing value of its mass, m is big. Hence,
work. the large mass of these heavy
(b) Watt vehicles causes more kinetic
4. (a) W = Fs energy.
= 2 500 N × 4 m (b) (i) Bullet fired from a pistol.
= 10 000 J (ii) Aeroplane taking off from runway
(b) Energy used = work done at airport.
= 10 000 J
W
(c) Power of crane, P = Formative Practice 7.3 (p. 226)
t
10 000 J 1. The Principle of Conservation of Energy
= states that energy cannot be created or
1.2 minutes
10 000 J destroyed but can only be converted from
= one form to another.
72 s
= 138.89 W 2. (a) P, R
(b) Q
3. (a) Gravitational potential energy
Formative Practice 7.2 (p. 221) = mgh
1. (a) Gravitational potential energy is = 2 kg × 10 m s × 2.5 m
–2
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,
x from the position of equilibrium. 1 mv = 50 J
2
2. (a) W = Fs 2
= 40 N × 0.5 m 1 × 2 kg × v = 50 J
2
= 20 J 2
2 –2
2
(b) Gravitational potential energy v = 50 m s
(c) Gravitational potential energy of v = 50 m s
2 –2
possessed by the chair = work done
on it = 7.07 m s –1
= 20 J
3. Distance of compression of spring
= original length length of Summative Practice 7 (pp. 228, 229)
–
of spring compressed spring 1. (a) Energy possessed by an object is
= 50 cm – 30 cm due to its position or condition.
= 20 cm (b) Energy possessed by a moving
= 0.2 m object.
Elastic potential energy 2. (a) N m
1 (b) Work
= Fx (c) stationary
2
1 (d) can
= (20 N) (0.2 m) (e) acceleration
2
= 2 J 3. (a) W = Fs
18

–2
= 5 kg × 10 m s × 2 m Explanation: This model of a roller
= 100 J coaster has vertical, winding
(b) Energy used by motor = work done and turning loops.
= 100 J
4. (a) Gravitational potential energy = mgh CHAPTER 8 Radioactivity
where m is the object mass Brain Teaser (p. 235)
g is the gravitational acceleration (a) 1 Ci = 3.7 × 10 Bq
10
h is the height (b) 1 Bq = 2.70 × 10 −11 Ci
1
(b) Elastic potential energy = Fx,
2 Formative Practice 8.1 (p. 237)
where F is the compression or 1. (a) Wilhelm Roentgen
stretching force (b) Henri Becquerel
x is the displacement from (c) Marie and Pierre Curie
equilibrium position 2. Radioactivity is the spontaneous decay
1
2
(c) Kinetic energy = mv , process of an unstable nucleus by
2 emitting radioactive radiation.
where m is the mass, 3. (a) curie (Ci), becquerel (Bq)
v is the velocity (b) The decay rate of an unstable
5. (a) Work = force × displacement nucleus.
= 200 N × 0.4 m 4. Carbon-14 (C-14), Radon-222 (Rn-222),
= 80 J Thorium-232 (Th-232), Uranium-238
(b) Elastic potential energy (U-238)
1
= Fx 5. Half-life, T , is the time taken for the
1
2 2
1 number of undecayed nuclei to be
= × 200 N × 0.4 m
2 reduced to half of its original value.
= 40 J
(c) Because part of the work done is Formative Practice 8.2 (p. 239)
used to bend the bow. 1. According to Dalton’s Atomic Theory, an
6. (a) Principle of Conservation of Energy atom is the smallest particle and cannot
(b) Vertical displacement of 2.5 cm from be further divided.
position Y. 2. (a) When an atom loses electrons.
(c) Potential energy at X = mgh (b) When an atom gains electrons.
40 5 3. (a) Q and S. In Q and S, the number of
–2
= kg × 10 m s × m
1 000 100 protons is more than the number of
= 0.02 J electrons.
Potential energy at Y = 0 J, so (b) R and T. In R and T, the number of
difference in potential energy electrons is more than the number of
= (0.02 – 0) J protons.
= 0.02 J (c) P. In P, the number of protons is the
7. Retort same as the number of electrons.
stand 4. (a) One electron is gained.
(b) The number of electrons in the ion
increases by one.
(c) Bromide ion, Br –

Brain Teaser (p. 243)
–6
1 μSv/h is equivalent to 10 J of ionising
radiation energy absorbed by 1 kilogram of
living tissue in a time interval of 1 hour.

Rubber hose
19

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 (c) Alpha radiation. It has the lowest
radiation, beta radiation, gamma ray penetration power.
and X-ray (any one) 5. (a) Lead (or aluminium)
(b) Non-ionising is radiation that does (b) For lead:
not produce ions while passing Advantage – Lead is an appropriate
through the air. shield from all types of radioactive
Examples of non-ionising radiation: radiation including gamma rays which
light (visible), infrared, radio waves have high penetration power.
2. (a) lower, higher Disadvantage – The high density of
(b) higher, lower lead makes the clothing too heavy.
3. (a) Cosmic rays, background radiation For aluminium:
(b) Nuclear accidents, nuclear tests, use Advantage – The lower density of
of radioisotopes in medical field aluminium makes the clothing less
4. (a) microSievert/hour (μSv/h) heavy.
(b) 1 Sv is 1 Joule of ionising radiation Disadvantage – Aluminium is a less
energy absorbed by 1 kilogram of efficient shield from gamma rays
living tissue. which have high penetration power.
(c) Radiation dose less than 0.2 μSv/h
5. The higher an individual is from the
surface of Earth, the stronger the cosmic Summative Practice 8 (pp. 252 – 254)
rays received. Hence, an individual who 1. (a)
is in an aeroplane at a high altitude will (b) ×
(c)
absorb more cosmic rays causing his
ionising radiation dose to exceed the 2. Radioactive decay is a spontaneous
safety level. process by which an unstable nucleus
6. Ionising radiation dose received by the emits radioactive radiation until the
student = 0.01 mSv/h × 2 h × 5 nucleus becomes more stable.
= 0.1 mSv 3. sodium-24 (Na-24)
4. 0 hours 5.2 hours 10.4 hours
Formative Practice 8.4 (p. 250) 32 g 16 g 8 g
1. (a) Carbon-14 dating to determine the
age of an ancient object. 15.6 hours 20.8 hours
(b) Cobalt-60 to treat cancer by killing 4 g 2 g
cancer cells.
(c) Phosphorus-32 to determine the Therefore the remaining mass of Pa-234
absorption rate of phosphate after 20.8 hours is 2 g.
fertilisers in plants. 5. (a) Ion formed is a positive ion because
(d) Uranium-235 to build weapons such Mg atom loses two electrons to form
2+
as atomic bombs. Mg ion.
(e) β-radiation to monitor the thickness of (b) Ion formed is a negative ion because F
–
metal sheets. atom gains one electron to form F ion.
2. (a) Gamma rays 6. (a) X-ray and gamma ray:
(b) Gamma rays preserve food by killing • are ionising radiation
the bacteria in the preserved food. • have high penetration power in air
3. Boxes with thick lead walls can prevent • are electromagnetic waves
all types of radioactive radiation emitted (b) (i) Sample Y. This is because the
by radioactive sources or radioactive strawberry in sample Y is still in
waste from escaping. good condition.
20

(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
radioactive radiation dose in magnetic field in the region in space.
preserved food is within the 4. Solar wind
normal level or safe level. 5. Comet
7. (a) • Wear appropriate protective
clothing.
• Detect radioactive radiation dose Formative Practice 9.2 (p. 265)
found on clothing with detectors 1. Phenomena that occur on the surface of
such as Geiger Müller tube which the Sun and in outer space.
gives a warning sound if the dose 2. Formation of aurora, disturbances to
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 B: Chromosphere
LED
C: Photosphere
D: Radiation zone
Empty mineral water E: Core
bottles wrapped F: Corona
in newspaper 2. 11 years
Explanation: 3. Sunspots
4. – Smartphone (mobile)
Representing – Internet
Component in component in
the model – TV broadcast
the system – Global positioning system (GPS)
5. All living things would die. Ionising
LED Beta radiation radiation in solar winds would reach
source Earth and be absorbed by living things at
levels exceeding the safety level. Hence,
Light rays Beta radiation the risks to the health of living things
would increase and this would be fatal.
Mineral water Bottles filled 6. Sketch of model: Student’s answer
bottles wrapped with drinking Explanation:
in newspaper water – Green plastic bag represents ‘Bow
Shock’
Mirror Beta radiation – White thread represents magnetic field
detector lines from other planets
– Red thread represents Earth’s
magnetic field
– Polystyrene cup represents a
CHAPTER 9 Space Weather
protective layer, the magnetosphere
Formative Practice 9.1 (p. 263) – Convex cover represents the part of
1. Photosphere, chromosphere, corona the magnetosphere that is directed
2. Prominence, solar flare, coronal mass towards the Sun
ejection – Plasticine represents Earth
3. Earth’s magnetosphere is defined as a
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
(b) Heliocentric model rational explanation about objects and
(c) Modified heliocentric model according phenomena in space based on their
to Kepler’s Law intellectual abilities.
2. (a) Similarity: In the Solar System 4. Because space probes are not built to
models built by Ptolemy return to Earth.
and Copernicus, Earth or 5. (a) To gather information about Saturn to
the Sun revolve in orbits. be sent back to Earth.
(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 land
Solar System model built – Predict yield of crops
by Copernicus, the Sun (b) – Explore regions to search for oil
is at the centre of Earth’s and mineral sources
orbit. – Map Earth’s surface
3. (a) Similarity: The Solar System models (c) – Oversee natural disasters such as
built by Copernicus and floods
Kepler are heliocentric – Oversee forest fires, oil spills in
models. the oceans and landslides
(b) Difference: In the Solar System model (d) – Detect enemy invasions from air,
built by Copernicus, Earth land and sea
and the planets revolve in – Detect nuclear tests
circular orbits whereas in 7. (a) A rocket is an aircraft that obtains its
the Solar System model thrust using a rocket engine.
built by Kepler, Earth and (b) To send astronauts, spaceships,
the planets revolve in satellites, remote sensing instruments
elliptical orbits. and space probes to space.
(c) Functions as a weapon by carrying
guided missiles.
Formative Practice 10.2 (p. 276) 8. Sketch of model: Student’s answer
1. Telescope Explanation:
2. (a) Discovery is a space shuttle.
(b) Hape is a rocket which sent Material Function
Discovery to space. Aluminium foil Shield against
3. (a) Remote sensing technology ionising radiations
(b) To identify the locations hit by flood from space
and determine the places to transfer
flood victims Cylindrical As a rocket
4. MACRES is responsible for all remote cardboard
sensing projects in Malaysia.
Black plastic Solar battery/
sheet Source of energy
Summative Practice 10 (pp. 278 – 280) for spaceship
1. (a) ×
(b) Cardboard in As a spaceship
(c) × the form of a
(d) × spaceship



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
1. (a) × (b) (c) × (d) absorb water to enable plants to carry out
photosynthesis.
2. P: Brain
Q: Spinal cord
R: Peripheral nerve CHAPTER 2 Respiration
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.

(b) Oxyhaemoglobin easily decomposes into
Oval window Cochlea
haemoglobin and oxygen when it reaches body
Auditory nerve Brain cells so that oxygen can diffuse into the cells.
6. (a) Azura may be allergic to pollen. In Spring,
(b) Light Cornea Aqueous humour
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 asthma patients.
stimuli compared to the palm of the hand. 7. (a) – Thickness of the wall
Fingertip has a thinner layer of epidermis and – Moisture of the wall
more touch receptors compared to the palm of – Surface area
the hand. – Network of capillaries
(c) Agree. The tongue is a sensory organ that has (b) (i) Asthma
receptors known as taste buds on the surface Symptom: Shortness of breath
of the tongue which is protected by skin Cause: Excessive release of mucus
epidermis. on the surface of alveolus
6. (a) The sense of smell helps us to detect danger reduces the surface area and
such as leakage of gas that might occur in rate of gaseous exchange in
the science laboratory. For example, we can the alveolus thereby causing
detect the presence of dangerous gases such as shortness of breath.
chlorine and ammonia from their smell. (ii) Bronchitis
(b) Dogs have a very sensitive sense of smell Symptom: Shortness of breath
because they have more sensory cells for smell Cause: Inflammation of the
than human and are more efficient to analyse bronchus in bronchitis
smell than human. patients caused by tar
7. (a) – Positive phototropism and irritants in cigarette
– Positive hydrotropism smoke reduces the rate of
(b) Positive phototropism ensures shoots and movement of air from the
leaves of plants obtain sufficient sunlight to nose to the lungs through
make food through photosynthesis. the bronchus. This causes
281

bronchitis patients to be Diastolic pressure reading is reading of blood
frequently breathless. pressure which is lower when heart ventricle
(iii) Emphysema slackens to facilitate blood flowing from the
Symptom: Shortness of breath whole body back to the heart.
Cause: The alveolus in emphysema 6. (a) (i) Eric, Roy
patients is damaged by (ii) Blood will coagulate.The victim may die.
dangerous substances in (b) (i) Individual 2.
the air such as irritants in This is because she fulfils the age
cigarette smoke. Hence, the condition of 18 years and above but less
surface area for gaseous than 60 years. She also fulfils the body
exchange in the alveolus is mass condition of more than 45 kg.
reduced causing shortness (ii) Pregnant women are not suitable to
of breath. donate blood.
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
respiratory system. 1. (a) Elements: Iron, Silver, Potassium, Tin
– Avoid places with polluted air. Compounds: Quartz, Bauxite, Galena,
To avoid inhaling air that contains harmful Hematite, Limestone
substances such as cigarette tar, carbon (b) Bauxite, Aluminium and oxygen
monoxide, sulphur dioxide, nitrogen dioxide, 2. (a) Tin(IV) oxide
haze, dust and pollen which are harmful to the (b) Carbon
respiratory system. (c) Tin + oxygen → Tin(IV) oxide
– Have proper exercise and lead a healthy lifestyle. 3. (b) (c)
To maintain a healthy respiratory system.
4. (a) Oxygen
(b) Potassium and sodium are very reactive metals.
CHAPTER 3: Transportation Paraffin prevents potassium and sodium from
reacting with oxygen and water vapour in the air.
Summative Practice 3
1. (a) PULSE (d) PHLOEM 5. (a) Oxygen
(b) TRANSPIRATION (e) HEART (b) To provide oxygen for the reaction.
(c) CAPILLARY (f) ANTIGEN (c) Heat the powdered metal until it glows before
2. (a) (b) × (c) × (d) × heating potassium manganate(VII) to provide
3. (a) Valve oxygen for the reaction.
(b) Transport oxygenated blood (d) To construct a reactivity series of metals.
(c) (i) Blood vessel Q has thick walls to
withstand high blood pressure. CHAPTER 5 Thermochemistry
(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 1
(b) Elastic potential energy = Fx,
carbonate is an exothermic reaction whereas the 2
reaction between hydrochloric acid and sodium where F is the compression or stretching force
hydrogen carbonate is an endothermic reaction. x is the displacement from equilibrium
position
1
2
CHAPTER 6 Electricity and Magnetism (c) Kinetic energy = mv ,
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
(c) Renewable energy source CHAPTER 8 Radioactivity
(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 8 g
(b) Shape of graph, direction of current and
15.6 hours 20.8 hours
voltage changes for direct current and
4 g 2 g
alternating current.
(c) (i) Alternating current Therefore the remaining mass of Pa-234 after
(ii) Direct current 20.8 hours is 2 g.
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
V p N p C: Photosphere F: Corona
(d) Using the formula, = 2. 11 years
V N
s s
3. Sunspots
10 V 100 turns
= 4. – Smartphone (mobile)
V 20 turns
s – Internet
20 turns
Secondary voltage, V = 10 V × – TV broadcast
s 100 turns
– Global positioning system (GPS)
= 2 V
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.
-2
= 5 kg × 10 m s × 2 m (b) Solar wind
= 100 J (c) Solar energy
(b) Energy used by motor = work done
= 100 J
4. (a) Gravitational potential energy = mgh Complete answers
for teachers
where m is the object mass
http://links.andl17.
g is the gravitational acceleration
com/BT_Science_283
h is the height
283

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





David Applin (2012). Biology, United Kingdom: Nelson Thornes

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

Gary Philpott and Jennifer Clifford (2009). Longman Physics 11-14 (2009 edition),
England: Longman.

nd
Ian J. Burton (2015). Cambridge O Level Biology Revision Guide, 2 Revision, United Kingdom:
Cambridge University Press.

Joanne Baker (2010). 50 ideas universe, United Kingdom: Quercus Editions Ltd, London.

Karen C. Timberlake (2018). Chemistry – An introduction to General, Organic and Biological
th
Chemistry, 13 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,
Pearson Education Limited.

Martin Redfern (2012). 50 ideas earth, United Kingdom: Quercus Editions Ltd.

Mary Jones, Geoff Jones (2015). Biology Coursebook, United Kingdom: Cambridge University
Press

Ooi Chong Oui, Suzita binti Mohd Resa and Umagowrie a/p Supramaniam (2012). Sains
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
Press.

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