2
WATER
2
Water
S ECTIONAL E XERCISE
2.1 The water cycle
Sectional EExercise
xercise
efer to Textbook
p.79–95
A. True or false (5 marks)
Write ‘T’ for a true statement and ‘F’ for a false statement.
Integrated Exercise
E
1.
When water freezes, it releases energy.
⑧
T
2.
Evaporation and condensation only take place at fixed temperatures.
⑧
F
3.
In the water cycle, the energy from the Sun causes water to evaporate from the sea.
$
T
4.
The water cycle keeps the total amount of water on Earth constant.
O
T
5.
The higher the humidity, the->
higher the rate of evaporation.
I
F
can take place at any
->
lower
⑨
B. Multiple-choice (5 marks)
Choose the correct answer for each question.
1.
Which of the following combinations correctly shows the physical states of water at −10 °C
and above 100 °C?
Spelling Corner
2.
At −10 °C
Above 100 °C
A.
Liquid
Liquid
B.
Liquid
Gas
C.
Solid
Liquid
D.
Solid
Gas
D
&
Karen is wearing a facial mask which contains a lot
of water. When she puts the mask on her face, she
feels cool. Which of the following correctly explains this
phenomenon?
32
A.
The water in the mask evaporates and absorbs energy.
B.
The water in the mask evaporates and releases energy.
C.
The water in the mask freezes and absorbs energy.
D.
The water in the mask freezes and releases energy.
③
A
Water
A.
Ice changes to water during melting.
B.
Water changes into steam during evaporation.
C.
Water changes to ice during freezing.
D.
Water vapour changes to water during condensation.
&
B
The following set-up is used to simulate the formation of rain in Nature.
Sectional EExercise
xercise
4.
Which of the following statements is INCORRECT?
zipper bag
ice
metal dish
transparent plastic container
beaker
coloured hot water
table lamp
hot pebble
Which of the following statements about the above experiment are correct?
(1)
Water evaporates into water vapour, which condenses on the lower surface of the metal
dish.
5.
The ‘rain’ is colourless.
(3)
The light from the table lamp removes the colour in the hot water.
A.
(1) and (2) only
B.
(1) and (3) only
C.
(2) and (3) only
D.
(1), (2) and (3)
⑧
A
A wet towel is hanging on a rack. The wet towel dries
Spelling Corner
E
(2)
faster when
A.
the air temperature is lower.
B.
the surface area of the towel exposed to air is smaller.
C.
there is more airflow.
D.
the humidity of air is higher.
Integrated Exercise
3.
2
⑨
C
C. Fill in the blanks (8 marks)
1.
Water can exist in three physical states: (a)
(c)
2.
gas
-
solid
-
, (b)
liquid
&
and
.
Water can change to water vapour below the boiling point in a process called
evaporation
.
33
2
Water
3.
In the water cycle, the energy from the Sun causes water to (a)
vapour, which then cools and (b)
condenses
=°@°
into water
to form water droplets higher up in the
⑤
clouds
sky. The water droplets join together to form (c)
and become heavy, they finally fall as (d)
E
evaporate
=
rain
. As the water droplets gather
, snow or hail.
Sectional EExercise
xercise
D. Questions (12 marks)
1.
Jack puts a cube of ice into a glass of hot water.
ice
hot water
Integrated Exercise
(a)
E
What happens to the ice? Does the ice absorb or release energy?
The ice melts (1m) and absorbs energy. (1m)
>
(b)
Does the water in the glass evaporate faster or slower after adding the ice? Explain
your answer.
(2 marks)
The water evaporates (i)
evaporation of water (ii)
Spelling Corner
E
2.
after adding the ice because the rate of
slower
(1m)
°
⑦
decreases (1m)
⑤x@_.⑦
when the temperature is lower.
Study the following situations.
(a)
In which case does the ground dry up faster?
I
higher.
(2 marks)
II
temperature (1m)
is
⑤dries up faster because the (ii) -
The ground in case (i) I (1m)
34
(2 marks)
Water
In which case do the clothes dry up faster?
II
a
humidity (1m)
The clothes in case (i) II (1m) dry up faster because the (ii) goin
is lower.
In which case do the hands dry up faster?
I
The hands in case (i)
(d)
(2 marks)
II
I (1m) dry up faster because there is more (ii)
airflow (1m)
.
G
In which case does the umbrella dry up faster?
I
(2 marks)
Spelling Corner
(c)
Sectional EExercise
xercise
I
(2 marks)
Integrated Exercise
(b)
2
II
exposed area (1m)
-
The umbrella in case (i) I (1m) dries up faster because the (ii)
of the umbrella is larger.
Total Score :
/ 30
35
2
Water
Dissolving
2.2
efer to Textbook
p.96–107
A. True or false (4 marks)
Write ‘T’ for a true statement and ‘F’ for a false statement.
1.
2.
Sectional EExercise
xercise
E
E
3.
4.
F
The rate of dissolving increases when the solute is in powdered form.
T
.
The amount of substance that can dissolve in a given amount of water is different for
different substances.
⑧
T
The solubility of a substance increases as the temperature increases.
F
&
(The solubility of a substance can
increase or decrease with temperatures.)
⑮
x⑦
*
B. Multiple-choice (5 marks)
Choose the correct answer for each question.
1.
Integrated Exercise
2.
Which of the following substances is insoluble in water?
A.
Jelly powder
B.
Salt
C.
Chalk dust
D.
Sugar
C
⑯
The following photo shows the ingredients of a drink.
Apple Tea with Aloe Vera Pulps
蘆薈粒蘋果茶
Spelling Corner
Ingredients: Water, Sugar, Apple Juice, Aloe Vera Pulps (10 g per bottle),
Flavourings, Vitamin C
成分：水、白糖、蘋果汁、蘆薈粒(每瓶含10克)、調味劑、維生素C
Which of the following is NOT a solute?
3.
36
Water is called the universal solvent because it can dissolve all substances.
(Water is called the universal solvent because it can dissolve many (but not all) different substances.)
>
A.
Aloe vera pulps
B.
Apple juice
C.
Flavourings
D.
Sugar
A
8
Which of the following statements about dissolving is INCORRECT?
A.
A solute dissolves in a solvent to form a solution.
B.
Water is the only solvent in the world.
C.
The rate of dissolving increases as the temperature of the solvent is higher.
D.
Two litres of water can dissolve more solute than one litre of water.
aloe vera pulp 蘆薈粒
flavouring 調味劑
8
B
Water
E
4.
2
The following graph shows the solubilities of four different substances at different
temperatures.
Amount of the substances that can
dissolve in 100 cm3 of water (g)
80
substance W
Sectional EExercise
xercise
substance Y
100
substance X
60
40
substance Z
20
Temperature (°C)
0
10
20
30
40
50
60
70
80
90
100
5.
Substance W
B.
Substance X
C.
Substance Y
D.
Substance Z
A
⑬
Which of the following will affect the solubility of a solute?
(1)
Stirring
(2)
Temperature
(3)
Surface area of solute
A.
(1) only
B.
(2) only
C.
(1) and (3) only
D.
(2) and (3) only
8
B
C. Fill in the blanks (6 marks)
1.
When a substance dissolves in a liquid, a (a)
dissolves is called a (b)
(c)
2.
solvent
solute
->⑤x@⑦
solution
. The liquid in which the substance dissolves is called a
.
Water is called a (a)
universal solvent
=@=°
. Many different substances are soluble in
water. However, there are still some substances that are (b)
E
3.
is formed. The substance that
Spelling Corner
E
A.
Integrated Exercise
From the graph, which substance is the most soluble at 60 ºC?
The solubility of a substance in water changes with
insoluble
>
temperature
in water.
.
37
2
Water
Water purification
2.3
efer to Textbook
p.108–124
A. True or false (5 marks)
Write ‘T’ for a true statement and ‘F’ for a false statement.
1.
2.
Sectional EExercise
xercise
3.
4.
5.
We can survive up to several weeks without water.
F
D
Amoeba and E.coli are the microorganisms commonly found in natural water.
D
T
Natural water does not contain any impurities.
⑧
F
(Without water,
one will likely die⑦
within a few days.)
⑤_5_.⑤
⑦
aF
(Natural water->
often
contains insoluble impurities, soluble impurities (e.g. salt) and microorganisms.)
.
.
Filtration can remove soluble impurities in water.
-.
cannot
Water needs to be heated to its boiling point in the distillation process.
T
8
B. Multiple-choice (5 marks)
Choose the correct answer for each question.
1.
In the process of sedimentation, adding some alum can
Integrated Exercise
dissolve insoluble impurities.
B.
kill microorganisms.
C.
cause the impurities to stick together.
D.
make the impurities lighter so that they can float on
water and then be removed easily.
2.
alum
A.
C
O
Leo uses the set-up as shown below to purify some muddy pond water.
muddy pond water
filter paper
Spelling Corner
40
X
Y
What are substances X and Y called?
X
Y
A.
Distilled water
Residue
B.
Filtrate
Residue
C.
Residue
Distilled water
D.
Residue
Filtrate
⑧
D
Water
4.
Which of the following substances can be found in a bottle of distilled water?
A.
Microorganisms
B.
Soluble impurities
C.
Insoluble impurities
D.
None of the above
D
&
Which of the following substances can be removed by the set-up below?
Sectional EExercise
xercise
3.
2
glass plate
sea water (with sand)
Bunsen burner
Salt
(2)
Sand
(3)
Microorganisms
A.
(1) only
B.
(1) and (3) only
C.
(2) and (3) only
D.
(1), (2) and (3)
D
8
Which of the following processes are involved in distillation?
(1)
Evaporation
(2)
Boiling
(3)
Condensation
A.
(1) only
B.
(1) and (3) only
C.
(2) and (3) only
D.
(1), (2) and (3)
C
&
C. Fill in the blanks (6 marks)
1.
During sedimentation, large solid impurities settle at the bottom of the container to form a
layer of
> .
->
sediment
2.
The liquid collected in filtration is called
3.
The water collected in distillation is called
4.
Distillation can remove (a)
and (c)
Spelling Corner
5.
(1)
Integrated Exercise
water
->
>
filtrate
.
⑦distilled water
.
microorganisms
soluble impurities
=-@=>
, (b)
insoluble impurities
.
41
2
Water
D. Questions (20 marks)
1.
(a)
From the diagram shown below, explain why insoluble impurities can be separated from
muddy pond water by filtration.
(2 marks)
insoluble impurities
muddy pond
water
filter paper
Sectional EExercise
xercise
filtrate
funnel
filtrate
Si
tiny pores (1m)
The filter paper has many (i) .@⑧·
. The (ii)
insoluble impurities (1m)
Integrated Exercise
are too large to pass through the pores on the filter paper.
(b)
The filtered pond water is not safe to drink. Explain why.
(2 marks)
-
It is because the filtered pond water may still contain (i)
-
and (ii)
2.
.
microorganisms (1m)
soluble impurities (1m)
Susan sets up the apparatus as shown to purify some sea water.
thermometer
Spelling Corner
waterI
in
-o
stopper
water out
⑤
X
Ot
anti-bumping
granule
flask
sea water
beaker
water in
Bunsen burner
->
Each answer (1m)
(a)
Susan has made THREE mistakes in setting up the apparatus. Circle the mistakes and
correct them on the above diagram.
42
(3 marks)
Water
(b)
Name apparatus X.
(i)
2
(1 mark)
Condenser (1m)
⑳?
(ii)
What is its function?
(1 mark)
condenses into water 55
(1m)
To cool the steam so that it
A ship crew is shipwrecked on an island without fresh water. Three crew members are
John
Sam
We can make a
device with sand
and gravel, and
let the muddy
pond water pass
through the
device.
We can boil the
muddy pond water
and then let the
vapour condense.
Wilson
(a)
Name the water purification methods suggested by the three crew members. (3 marks)
-
Method suggested by John:
sedimentation (1m)
filtration (1m)
-
Method suggested by Sam:
-
Method suggested by Wilson:
(b)
distillation (1m)
Complete the table below to show whether the impurities can be removed by the three
methods. Put a ‘✓’ in the box if the impurity can be removed.
(Note: One mark would be deducted for each wrong answer.)
Method
suggested by
Leaves and
mud
Small solid
impurities
John
✓ (1m)
✓ (1m)
>
✓ (1m)
-
✓ (1m)
->
>
Sam
Wilson
(c)
Integrated Exercise
We can let the muddy
pond water stand for
about an hour.
Sectional EExercise
xercise
discussing how to obtain clean water from muddy pond water.
✓ (1m)
=
(7 marks)
Soluble
impurities
✓ (1m)
⑳=>
Microorganisms
Spelling Corner
3.
✓ (1m)
>
Referring to (b), which method can the crew use to obtain clean water from the muddy
pond water?
(1 mark)
Method suggested by Wilson/Distillation (1m)
Total Score :
/ 36
43
Water
2
I NTEGRATED E XERCISE
A. True or false (10 marks)
Write ‘T’ for a true statement and ‘F’ for a false statement.
Evaporation and condensation are the two main processes involved in the water cycle.
T
⑧
4.
Water evaporates faster in a cold environment than in a hot environment.
F
C
5.
A solute dissolves faster when the solution is stirred.
⑧
T
6.
Sugar has different solubilities at different temperatures.
T
⑧
7.
Water purified by sedimentation still contains microorganisms.
T
⑨
Filtration can remove salt from salt water.
F
⑧
8.
9.
hot
cold
-
(Salt is soluble in water. It cannot be removed by filtration.)
·
Pure water can be obtained by distillation.
8
T
*
10. Microorganisms in water can be killed by adding fluoride.
⑧
F
->
>
cannot
B. Multiple-choice (10 marks)
Choose the correct answer for each question.
1.
What are the names of processes W, X, Y and Z?
W
X
Y
ice
Z
water
Sectional Exercise
E
3.
F
⑧
releases
Spelling Corner
E
⑱
F
2.
Water only evaporates at 100 ºC.
can
evaporate at any temperature
When water vapour condenses into water, it absorbs energy.
steam
W
X
Y
Z
A.
Melting
Boiling
Freezing
Condensation
B.
Melting
Condensation
Boiling
Freezing
C.
Freezing
Boiling
Melting
Condensation
D.
Freezing
Condensation
Melting
Boiling
Integrated Exercise
1.
⑤
A
49
2
Water
Directions: Questions 2 and 3 refer to the following information.
A beaker of crushed ice is heated. The graph below shows the changes in its temperature.
The temperature of the ice (or water) against time
Temperature (ºC)
R
S
100
Sectional Exercise
80
60
40
20
0
Integrated Exercise
2.
3.
Spelling Corner
4.
P
Q
1
2
3
4
5
Time (min)
6
7
8
9
10
11
12
Which of the following correctly shows the processes take place at parts PQ and RS?
PQ
RS
A.
melting
evaporation
B.
freezing
boiling
C.
freezing
evaporation
D.
melting
boiling
D
-
Which of the following statements are correct?
(1)
Ice absorbs energy at PQ.
(2)
Water releases energy at RS.
(3)
Both solid and liquid exist at PQ.
A.
(1) and (2) only
B.
(1) and (3) only
C.
(2) and (3) only
D.
(1), (2) and (3)
E
B
The water in the oceans, rivers and on land surfaces absorbs energy from the Sun and becomes
water vapour. What is this process called?
50
A.
Melting
B.
Boiling
C.
Evaporation
D.
Condensation
C
⑧
Water
5.
2
Some scientists estimated that the total volume of water on Earth is about 1.4 billion km3.
How much water was there on Earth 3000 years ago?
7.
B.
About 1.4 billion km3
C.
About 0.7 billion km3
D.
About 0.1 billion km3
B
C
Under which of the following conditions will the evaporation of water be the fastest?
Temperature
Humidity
A.
25 ºC
60%
B.
25 ºC
80%
C.
35 ºC
60%
D.
35 ºC
80%
&
C
In each of the following beakers, the water temperatures, the volumes of the water and the
Sectional Exercise
6.
About 2.8 billion km3
A.
B.
sugar in pieces
C.
sugar in powdered
form
D.
stir
stir
sugar in pieces
sugar in powdered
form
D
&
8.
Integrated Exercise
masses of the sugar are the same. In which beaker will the sugar dissolve the fastest?
Which of the following methods can produce drinking water from sea water?
(1)
Sedimentation
(2)
Filtration
(3)
Distillation
A.
(1) only
B.
(3) only
C.
(1) and (3) only
D.
(2) and (3) only
Spelling Corner
E
A.
⑤
B
51
2
Water
9.
Four students were asked to purify some pond water by filtration. Which of the following is
the proper way to carry out filtration?
A.
B.
glass rod
Sectional Exercise
beaker
C.
beaker
D.
glass rod
Integrated Exercise
Spelling Corner
52
glass rod
beaker
beaker
A
⑰
10. Which of the following are the problems caused by E. coli in waste water?
(1)
Diarrhoeal diseases
(2)
Using up the oxygen in water
(3)
Contamination of seafood
A.
(1) and (2) only
B.
(1) and (3) only
C.
(2) and (3) only
D.
(1), (2) and (3)
S
B
Water
2
C. Matching (5 marks)
Match the terms with their descriptions by writing the corresponding letters i, ii, etc. in the blanks
below.
Description
(a) Condensation
(i)
(b) Rate of dissolving
(ii) is the process in which a gas changes to a liquid.
(c) Solubility
(iii) can kill the microorganisms in water.
X(e)
(iv) refers to how fast a solute can dissolve in a solvent.
Fluoridation
(v) is the maximum amount of a solute which can dissolve in a
given amount of solvent.
5.
ii
(b)
=>
iv
(c)
⑤
v
(d)
iii
(e)
Each answer (1m)
-x
->
i
D. Question (25 marks)
1.
There is a mixture of salt and sand in a beaker. Fill in the blanks below to describe how you
can separate them.
Mixture of salt
(7 marks)
add water and stir
and sand
>
Salt (a) dissolves (1m) in water.
Sand is (b)
insoluble (1m) .
filtration (1m)
(c) -
Sand (1m)
(d) ⑨
is the residue.
(e)
Salt@°x
solution (1m)
⑰
°
is the filtrate.
heat the watch glass containing
the
filtrate
bath
until
over
all
a
steam
the
liquid
Integrated Exercise
(a)
Sectional Exercise
(d) Chlorination
can help prevent tooth decay.
Spelling Corner
E
Term
evaporates (1m)
(f) Salt (1m)
(g) -
is left on the watch glass.
53
2
Water
E
2.
Paul performs an experiment to find out how the solubilities of two substances change with
water temperatures. He presents his experimental results in the graph below.
The solubilites of substance X and Y
substance X
50
45
Sectional Exercise
40
35
Amount of substance
that can dissolve in
100 cm3 of water (g)
30
25
20
15
Integrated Exercise
10
5
substance Y
0
10
20
30
40
50
60
70
80
90
Water temperature (°C)
(a)
Spelling Corner
(b)
(c)
According to the graph,
(2 marks)
(i)
at which water temperature do substance X and substance Y have the same
54 ºC (1m)
>
solubility? ⑰>
(ii)
at which water temperature does the solubility of substance X equal to 30 g per
80 ºC (1m)
100 cm3 of water? =@°
How does the solubility change with the water temperature for
(i)
substance X?
(ii)
substance Y?
Its solubility
increases (1m)
>
Its solubility decreases with the water temperature. (1m)
-
What will be observed?
Some substance Y cannot dissolve. (1m)
=°@°@>
(ii)
(2 marks)
with the water temperature.
Paul adds 31 g of substance Y to 100 cm3 of water at 40 ºC.
(i)
Describe how you can dissolve all the 31 g of substance Y.
=-*π°$=@π@*°*&
Lower the temperature of the water below 20 ºC. (1m)
54
100
(2 marks)
3
LOOKING AT LIVING
THINGS
3
Looking at Living Things
S ECTIONAL E XERCISE
3.1 Living things
Sectional Exercise
efer to Textbook
p.151–158
A. True or false (6 marks)
Write ‘T’ for a true statement and ‘F’ for a false statement.
Integrated Exercise
1.
All living things need to feed on others to live.
F
⑧
2.
Animals usually grow faster than plants.
F
⑧
3.
For plants, only the shy plant can react to stimuli.
F
⑧
4.
Non-living things can have some of the vital functions of living things.
D
T
5.
Yeast is a kind of living thing.
D
T
6.
Not all living things can be seen with the naked eye.
T
D
B. Matching
(5 marks)
Match the following vital functions with ‘animals’ or ‘plants’ by writing the corresponding letters
a, b, etc. in the blanks below.
(Hint: Some vital functions are for both animals and plants.)
Spelling Corner
Vital functions
(a) Need food
(b) Need to breathe
(c) Usually detect and react to stimuli slowly
(d) Usually move faster
(e) Can reproduce
(f)
Can excrete
Animals:
yeast 酵母菌
60
a, b, d, e, f
5
Each answer
(0.5m)
t
&
e
Plants:
a, b, c, e, f
=>
>
Each answer (0.5m)
⑤
Looking at Living Things
3
C. Multiple-choice (5 marks)
Choose the correct answer for each question.
3.
Running water
(2)
Grass
(3)
Bread mould
A.
(1) and (3) only
B.
(1) and (4) only
C.
(2) and (3) only
D.
(2) and (4) only
(4)
Fire
B
D
Sectional Exercise
(1)
A rabbit hides itself when it sees a hunter. This shows that the rabbit
A.
can grow.
B.
needs to breathe.
C.
needs food.
D.
can detect and react to stimuli.
⑧
D
The photos below show some sunflowers and salmons.
sunflower
salmon
Both of them are living things because
(1)
they need to take in food.
(2)
they need to breathe.
(3)
they can reproduce.
(4)
they can detect and react to stimuli.
A.
(1) and (3) only
B.
(1), (3) and (4) only
C.
(2), (3) and (4) only
D.
(1), (2), (3) and (4)
Integrated Exercise
2.
Which of the following are non-living things?
Spelling Corner
1.
C
61
3
Looking at Living Things
4.
The electric robot dog on the right can move. It has sensors
so that it can detect and react to stimuli. However, it is
NOT a living thing because
Sectional Exercise
5.
(1)
it does not grow.
(2)
it does not need energy.
(3)
it cannot reproduce.
A.
(1) and (2) only
B.
(1) and (3) only
C.
(2) and (3) only
D.
(1), (2) and (3)
The photo below shows a dandelion releasing seeds into the air. Which vital function of living
things is shown?
Integrated Exercise
A.
Can move
B.
Excrete
C.
Can reproduce
D.
Need food
C
D
D. Questions (14 marks)
1.
Which vital functions of living things does each of the following activities show?
(7 marks)
Spelling Corner
(a)
The bud of a sunflower turns to the Sun.
Movement (1m)
(b)
The leaves fall off from trees.
Base
Excretion (1m)
(c)
A woman is having a baby.
(d)
Louis pulls his hand away from a hot object.
Sensitivity (1m)
Ext
(e)
Sarah is eating a sandwich.
Nutrition (1m)
gre
(f)
Dennis gets breathless after running a 400 m race.
ge
Respiration (1m)
(g)
Cheryl’s feet are getting bigger and she needs
a new pair of shoes.
62
B
&
sensor 感應器
dandelion 蒲公英
=
Reproduction (1m)
Growth (1m)
->
3
Looking at Living Things
Grouping of living things
3.2
efer to Textbook
p.159–176
A. True or false (6 marks)
Write ‘T’ for a true statement and ‘F’ for a false statement.
Sectional Exercise
1.
Classification is only useful in science.
F
&
2.
Some living things in the world have not been identified by scientists.
20
T
3.
All invertebrates live on land. (Jellyfish and lobsters are invertebrates that live in the ocean.)
4.
Reptiles use lungs for breathing.
5.
A turtle is an amphibian as it can live in water and on land.
6.
The body temperatures of small birds are usually affected by the surroundings.
8F
④
°
@5*
T
D
F
⑧
F
B. Multiple-choice (8 marks)
Choose the correct answer for each question.
Integrated Exercise
1.
Some animals are classified into two groups as shown below.
Group 1
Group 2
dolphin
salmon
parrot
tadpole
penguin
seahorse
The animals are classified according to
Spelling Corner
64
2.
A.
what they eat.
B.
how they breathe.
C.
where they live.
D.
how they reproduce.
⑧
B
Which of the following animals has/have lungs for breathing?
(1) Killer whale
(2) Whale shark
(3) Sea turtle
A.
(1) only
B.
(3) only
C.
(1) and (3) only
D.
(2) and (3) only
.
C
Looking at Living Things
3
Directions: Questions 3 and 4 refer to the following description.
Hayley classifies six animals into two different groups as shown below.
3.
4.
5.
Which of the following combinations about the animals in Group P and Group Q is correct?
Group P
Group Q
A.
Amphibians
Reptiles
B.
Mammals
Amphibians
C.
Mammals
Reptiles
D.
Vertebrates
Invertebrates
⑧
C
All of the above animals have
(1)
a backbone.
(2)
hair.
(3)
lungs.
A.
(1) only
B.
(2) only
C.
(1) and (3) only
D.
(2) and (3) only
Spelling Corner
Group Q
Integrated Exercise
Sectional Exercise
Group P
8
C
Which of the following statements about mammals is correct?
A.
Mammals live on land.
B.
Mammals give birth to live young.
C.
Male mammals do not have mammary glands.
D.
The body temperatures of all mammals are the same.
③
B
65
3
Looking at Living Things
6.
Which of the following plants does NOT have structure X shown
structure X
on the right?
Sectional Exercise
7.
A.
Carrot
B.
Fern
C.
Grass
D.
Moss
&
D
cross section of
a stem
Which of the following is a vascular plant without seeds?
A.
B.
C.
D.
Integrated Exercise
D
A
8.
Which of the following statements about seed plants is/are correct?
Spelling Corner
④
(1)
All seed plants are vascular plants. (All seed plants have vascular tissues.)
(2)
All non-flowering plants are seedless plants. (Some non-flowering plants produce seeds,
(3)
All seed plants are flowering plants. (Some seed plants do not produce flowers, for example, pines.)
A.
(1) only
B.
(2) only
C.
(1) and (3) only
D.
(2) and (3) only
for example, pines.)
O
A
C. Fill in the blanks (7 marks)
1.
Most animals on Earth are (a)
=>
invertebrates
. They do not have a (b)
backbone
o
.
The remaining are vertebrates.
2.
Vascular plants have (a)
(b)
3.
66
Zegg
nutrients
and (c)
vascular tissues
minerals
for transporting water,
through the roots, stems and leaves.
Non-vascular plants are usually found in (a)
damp
5=@
through the body surface as they have no (b)
=>
roots
places. They absorb water
.
Looking at Living Things
3
D. Questions (25 marks)
Are the following two statements correct? Explain your answer.
This statement is (i)
(ii)
reptiles (1m)
>
⑳>
correct (1m)
(6 marks)
(correct / incorrect). Sea turtles belong to
, and their bodies have (iii)
.
hard and dry.
scales (1m) . Frogs belong
*
amphibians (1m) and they have (v) moist skin (1m)
to (iv) ④*
but no (vi)
(b)
Penguins are not birds as they cannot fly.
(4 marks)
This statement is (i)
⑤°@°
incorrect (1m)
(correct / incorrect).
Penguins have a (ii)
beak (1m)
>
=>
for feeding and have
(iii)
*
feathers (1m)
⑮⑦⑤
scales (1m) .
over the body. Their body temperatures
are not (1m) (are / are not) easily affected by the surroundings.
(iv) ⑦°@=°⑦
2. Complete the table below to compare between fern and pine.
I
Fern
Vascular plant /
non-vascular plant?
Seed plant /
seedless plant?
Flowering plant /
non-flowering plant?
(8 marks)
Pine
(a)
vascular plant (1m)
(b)
vascular plant (1m)
(c)
seedless plant (1m)
(d)
seed plant (1m)
(e)
non-flowering plant (1m)
(f)
non-flowering plant (1m)
Method for reproduction
produces (g) spores (1m)
for reproduction
Sectional Exercise
Sea turtles and frogs belong to two different groups of vertebrates.
Integrated Exercise
(a)
Spelling Corner
1.
cones (1m)
produces (h)
which contain seeds for
reproduction
67
Looking at Living Things
Living things and habitats
3.3
3
efer to Textbook
p.177–180
A. Multiple-choice (3 marks)
Choose the correct answer for each question.
Both polar bears and walruses can survive the polar region.
polar bear
Sectional Exercise
1.
walrus
Which of the following is/are the common feature(s) they share to help them adapt to a cold
3.
Both of them are covered with thick dense fur.
(2)
Both of them have a thick layer of fat under skin.
(3)
Both of them have hair colour for camouflage.
A.
(1) only
B.
(2) only
C.
(1) and (3) only
D.
(2) and (3) only
⑧
B
Which of the following combinations about the living thing and its habitat is INCORRECT?
Living thing
Habitat
A.
Scorpion
Desert
B.
Squid
Ocean
C.
Water lily
Polar region
D.
Zebra
Grassland
C
⑧
Spelling Corner
2.
(1)
Integrated Exercise
environment?
Which of the following is NOT the adaptation of an egret for living
in a wetland?
A.
Long legs to walk in water
B.
Wings for flying
C.
Long pointed beak to catch prey
D.
White feathers for camouflage
D
⑧
69
3
Looking at Living Things
B. Matching
(4 marks)
Match the following animals with the correct groups of vertebrates and habitats. The first one has
been done for you as an example.
Animal
Sectional Exercise
Integrated Exercise
Group of vertebrates
Habitat
(a)
(1) Birds
(i) Desert
(b)
(2) Fish
(ii) Wetland
(c)
(3) Reptiles
(iii) Tropical rainforest
(d)
(4) Mammals
(iv) Freshwater pond
(e)
(5) Amphibians
(v) Ocean
Spelling Corner
(a)
2
v
(b)
·
1
ii
(c)
4
o
i
(d) 8
5 80
iv
(e) 88
3
iii
Each answer (0.5m)
@°@°
*@π⑤x=x@°
C. Fill in the blanks (6 marks)
1.
The natural environment where a living thing lives is called a (a)
example, chimpanzees and parrots live in a (b)
70
tropical rainforest
=@°=
habitat
.
. For
3
Looking at Living Things
3.4 Biodiversity
& 3.5 Reduction in biodiversity
efer to Textbook
p.180–194
A. True or false (4 marks)
Write ‘T’ for a true statement and ‘F’ for a false statement.
Sectional Exercise
1.
Biodiversity is the existence of many different kinds of living things.
2.
Tropical rainforests and deserts have the greatest biodiversity on Earth.
3.
4.
·
T
F
(Tropical rainforests and coral reefs have the greatest biodiversity on Earth.)
energet
All microorganisms are harmful to other living things.
8.
F
All the living things in an ecosystem are interdependent on each other.
⑤
T
B. Multiple-choice (2 marks)
Choose the correct answer for each question.
1.
Integrated Exercise
2.
Which of the following roles of animals in an ecosystem is INCORRECT?
A.
Honey bees can help plants reproduce by spreading pollen.
B.
Cows produce manure which will cause serious pollution.
C.
Small fish acts as the food source for some water birds.
D.
Earthworms move in the soil to help keep the soil loose and moist.
B
o
Humans depend on plants and animals for resources such as
Spelling Corner
(1)
raw materials.
(2)
food.
(3)
medicines.
(4)
oxygen.
A.
(1) and (2) only
B.
(1), (2) and (3) only
C.
(1), (2) and (4) only
D.
(1), (2), (3) and (4)
D
⑧
C. Fill in the blanks (3 marks)
1.
Biodiversity is important for keeping the ecosystem
sustainable
⑳.
.
and providing
resources for humans.
2.
Some living things are no longer exist now due to natural causes. We say they are
(a)
=>.
extinct
. Human activities also affect biodiversity. Some living things are in
danger of extinction and they are known as (b)
manure 糞肥
72
endangered species
-
.
Looking at Living Things
3
I NTEGRATED E XERCISE
A. True or false (8 marks)
Plants do not excrete as they do not take in food.
F
⑨
2.
A key can only be used to distinguish between plants and animals.
F
&
Amphibians use lungs to breathe on land and use gills to breathe in water.
F
⑯
3.
4.
e
All flowering plants live on land.
(Young amphibians have gills for breathing in water; while adults breathe through lungs and skin.)
Biodiversity is important for keeping the ecosystem sustainable.
·
6.
Plants will never become endangered species.
F
&
7.
Switching off unnecessary lights can help conserve the environment.
⑧
T
8.
Reducing pollution is a way to protect endangered species.
T
5.
s
(Some flowering plants live in water, for example, water lilies.)
⑧@π⑤
F
T
B. Multiple-choice (9 marks)
Choose the correct answer for each question.
1.
The following photos show a plant called Venus flytrap. It can trap insects and digest them.
Venus
flytrap
Integrated Exercise
1.
Sectional Exercise
Write ‘T’ for a true statement and ‘F’ for a false statement.
According to the photos above, which of the following vital functions of living things does
Venus flytrap show?
2.
(1)
Need food
(2)
Can Reproduce
(3)
Can Move
A.
(1) only
B.
(3) only
C.
(1) and (3) only
D.
(2) and (3) only
Spelling Corner
insect
C
⑧
Which of the following is the key feature of most plants?
A.
They live in water or damp places.
B.
They produce flowers.
C.
They have vascular tissues.
D.
They make their own food by photosynthesis.
Venus flytrap 捕蠅草
digest 消化
D
⑧
77
3
Looking at Living Things
3.
Which of the following is a vertebrate?
A.
B.
C.
D.
B
*
Sectional Exercise
Directions: Questions 4 and 5 refer to the following groups of animals.
Groups of animals
Integrated Exercise
4.
5.
6.
(1)
goose, duck, penguin
(2)
whale, kangaroo, rabbit
(3)
butterfly, dragonfly, housefly
(4)
tortoise, crocodile, snake
Which group(s) of animals lay(s) shelled eggs?
A.
(1) and (4) only
B.
(2) and (3) only
C.
(1), (2) and (4) only
D.
(1), (3) and (4) only
A
8
Which group(s) of animals’ body temperatures are not easily affected by the surroundings?
A.
(1) and (2) only
B.
(1), (2) and (4) only
C.
(2), (3) and (4) only
D.
(1), (2), (3) and (4)
A
⑨
The key below is used to classify three plants.
Spelling Corner
Vascular plants
With seeds
Without seeds
With flowers
Without flowers
X
Y
Z
Which of the following is the correct combination of the three plants?
X
Y
Z
A.
Pine
Tulip
Fern
B.
Tulip
Fern
Moss
C.
Tulip
Pine
Fern
D.
Pine
Fern
Moss
dragonfly 蜻蜓
78
C
8
Looking at Living Things
7.
3
The following diagram shows a key to classify different animals.
Animals
Have
Do not
Have
Do not
hair
have hair
scales
have scales
Panda
Penguin
Crocodile
Frog
With gills
Without gills
Clownfish
Jellyfish
Sectional Exercise
Y
Which of the following can be the correct combinations of X and Y?
X
Y
A.
Lay eggs on land
Do not lay eggs on land
B.
Have lungs for breathing
Have gills for breathing
C.
Body temperature not easily
Body temperature changes
affected by the surroundings
with the surroundings
Have two legs
Have four legs
D.
8.
C
⑧
Mikania is a foreign species to Hong Kong. It is a climber plant that comes from South and
Central America. It grows quickly, climbs up and covers other plants to get more sunlight.
Which of the following can be the possible effect(s) brought by Mikania which can affect the
Integrated Exercise
X
Without legs
Spelling Corner
With legs
biodiversity in Hong Kong?
(1)
Mikania may release toxins that can kill the plants nearby.
(2)
Mikania may block the sunlight from reaching other plants.
(3)
Mikania may compete for nutrients and water with the plants nearby.
A.
(1) only
B.
(2) only
C.
(1) and (3) only
D.
(2) and (3) only
D
S
79
3
Looking at Living Things
3.
Read the article below and answer the questions that follow.
Adaptation of a hedgehog to survive the winter
Sectional Exercise
Hedgehogs hibernate in winter. Before
hibernation, they take in a lot of food to
store fat under the skin to keep them
warm. Hedgehogs can regulate their body
temperatures which are not easily affected
by the surroundings.
Integrated Exercise
During hibernation, their body temperature and heart rate will become
lower to save the energy used by their bodies. Hedgehogs will also curl up
into a ball. This can reduce the exposed body surface area to reduce the
heat loss. When spring returns, their body will return to normal gradually
and they will wake up.
(a)
Hedgehogs have hair which is modified into spines.
(i)
Which group of vertebrates do hedgehogs belong to?
(1 mark)
Mammals (1m)
(ii)
State TWO reasons to support your answer in (a)(i).
(2 marks)
~,
They have hair (1m) and can regulate their body temperatures which are not easily affected
Spelling Corner
by the surroundings. (1m)
(iii)
Apart from reducing heat loss, hedgehogs will also curl into a ball when they are
in danger. Briefly explain why.
(1 mark)
-nee
The sharp spines can protect them from being attacked. (1m)
(b)
Hedgehogs are commonly found in grassland. The diagram below shows the interaction
between hedgehogs and other animals living in the same habitat.
eaten by
oak leaves
82
hedgehog 刺猬
hibernate 冬眠
spine 刺
eaten by
snail
hedgehog
3
Looking at Living Things
If the number of snails decreases, how would this affect the numbers of oak trees and
hedgehogs?
(2 marks)
Eme
The number of oak trees would increase. (1m)
The number of hedgehogs would decrease. (1m)
4.
X
Sustainable forest management has become more popular in recent years. It can help restore
the forests and the habitats of living things. The diagram below shows the life cycle of a
Sectional Exercise
sustainable forest.
10 years old
25 years old
30 years old
seedlings
young trees
mature trees
felled trees
Why are sustainable forests important to help protect biodiversity?
Cutting down trees will lead to the (i)
destruction of habitats (1m)
Living things cannot survive and this results in (ii)
(3 marks)
of living things.
reduction of biodiversity (1m)
.
Sustainable forests can help restore forests by replacing felled trees with
(iii)
seedlings (1m)
and allow them to grow into mature trees, so that the forests will
Spelling Corner
(a)
1 year old
Integrated Exercise
Life cycle of a sustainable forest
not be used up.
(b)
State TWO ways that we can do to help conserve the forests.
(2 marks)
Tree planting (1m) / Reduce paper use (1m) / Reuse paper (1m)
(Or any other reasonable answers)
sustainable forest management 森林可持續經營
felled 被砍伐的
83
4
CELLS, HUMAN
REPRODUCTION AND
HEREDITY
4
Cells, Human Reproduction
and Heredity
S ECTIONAL E XERCISE
4.1 Cells
Sectional Exercise
Integrated Exercise
Spelling Corner
2
efer to Textbook
p.3–21
A. True or false (6 marks)
Write ‘T’ for a true statement and ‘F’ for a false statement.
1.
All living things are made up of more than one cell.
F
&
2.
Amoeba is an example of unicellular organisms.
T
&
3.
A plant cell has a nucleus but an animal cell does not.
F
⑧
4.
Light microscopes are commonly used in the school laboratory.
T
⑤
5.
A longer objective has a higher magnification.
T
8
6.
There are 23 pairs of chromosomes in a human body cell.
T
③
B. Multiple-choice (9 marks)
Choose the correct answer for each question.
1.
2.
Which of the following structures can only be found in plant cells but not in animal cells?
(1)
Cell wall
(2)
Cytoplasm
(3)
Chloroplast
A.
(1) and (2) only
B.
(1) and (3) only
C.
(2) and (3) only
D.
(1), (2) and (3)
B
.
8
The photomicrograph shows some cells. Which of the following
is the function of structure X of the cells?
A.
To support and give shape to the cell
B.
To carry out photosynthesis
C.
To control cell activities
D.
To carry out chemical reactions
X
A
&
Cells, Human Reproduction and Heredity
4
Directions: Questions 3 and 4 refer to the following eyepieces and objectives for a light
microscope.
4.
5X, 10X, 15X
Objectives
4X, 10X, 40X, 100X
What is the lowest and highest magnification of the microscope?
Lowest magnification
Highest magnification
A.
× 50
× 20
B.
× 50
× 1500
C.
× 20
× 600
D.
× 20
× 1500
D
⑤
Which of the following combinations allows the observation of the largest number of cells in
Sectional Exercise
3.
Eyepieces
Objective
A.
5X
4X
B.
5X
100X
C.
10X
4X
D.
15X
40X
A
③
The picture on the right is observed under a microscope. Which of the
following is the image observed?
A.
B.
C.
D.
Spelling Corner
5.
Eyepiece
Integrated Exercise
a specimen?
C
⑧8
3
4
Cells, Human Reproduction and Heredity
6.
7.
Sectional Exercise
8.
Integrated Exercise
9.
To prepare a slide of ox eye cells, we add methylene blue solution to the cells to
A.
avoid the formation of air bubbles on the slide.
B.
stain the cells for easier observation.
C.
kill the microorganisms on the cells.
D.
preserve the colours of the structures.
B
8
Which of the following statements about the nucleus is correct?
A.
It carries genetic materials DNA.
B.
It is at the centre of all cells.
C.
It contains structures which produce food.
D.
It controls the movement of substances into and out of the cell.
A
-
The structures shown in the photomicrograph below are
A.
plant cells.
B.
animal cells.
C.
chromosomes.
D.
DNA.
8
C
A girl was born with chromosomal disorders. Which of the following can be the full set of
Spelling Corner
chromosomes in her body cell?
(1)
1
(2)
2
3
6
7
8
13
14
15
19
20
9
21
4
5
10
11
12
16
17
22
(3)
1
6
2
3
7
8
18
13
14
XX
19
20
9
15
21
4
5
10
11
12
16
17
22
1
6
2
3
7
8
18
13
14
XY
19
20
A.
(1) only
B.
(2) only
C.
(1) and (3) only
D.
(2) and (3) only
9
15
10
16
21
22
4
5
11
12
17
18
X
⑧
C
xπ@x
5
• In (1), there is an extra chromosome 21. This is known as Down syndrome.
• In (3), an X chromosome is missing. This is known as Turner syndrome (特納氏綜合症).
It is a chromosomal disorder in females.
4
Cells, Human Reproduction and Heredity
4
C. Questions (32 marks)
Make a biological drawing to show the structures of any two cells in the photomicrograph
below. Label the drawing with the words given.
cell membrane
cell wall
(7 marks)
cytoplasm
nucleus
⑱
Sectional Exercise
cell wall
cytoplasm
nucleus
Correct drawing (1m)
Correct labellings (4m)
Use smooth and clear
solid lines (1m)
Draw in pencil (1m)
The following diagram shows an animal cell undergoing an important process.
Integrated Exercise
2.
cell
membrane
S
R
Q
P
X
Y
(a)
Name the process.
(1 mark)
Cell division (1m)
-
(b)
Describe what is happening during period X.
(2 marks)
Spelling Corner
1.
e
see
The nucleus and the cytoplasm (1m) divide into two. (1m)
(c)
Describe what is happening during period Y.
(2 marks)
The daughter cells absorb nutrients (1m) and grow bigger. (1m)
-nee
(d)
At which stage (P, Q, R or S) does the cell make a copy of the genetic materials?
(1 mark)
P (1m)
5
Cells, Human Reproduction and Heredity
4.2 How are cells organized in living things?
4
efer to Textbook
p.22–28
A. True or false (5 marks)
1.
Different types of cells have different sizes, shapes and functions.
T
8
2.
Nerve cells are short so they can carry messages faster.
④
F
E
3.
Some organs group together to form a tissue.
F
⑧
E
4.
Different systems work together to support our lives and keep us healthy.
T
⑧
E
5.
The leaf is one of the organs of plants.
T
&
B. Multiple-choice (3 marks)
Choose the correct answer for each question.
E
2.
3.
cell X
A.
a root hair cell.
B.
a transporting cell.
C.
a leaf cell.
D.
a fat cell.
A
8
Which of the following correctly arranges the levels of organization?
A.
cell, organ, tissue, system
B.
cell, tissue, organ, system
C.
tissue, system, organ, cell
D.
tissue, system, cell, organ
B
⑧
Each small circle in the following diagrams represents a cell. Which of the diagrams best
represents a system?
A.
B.
C.
D.
Integrated Exercise
E
Cell X is found in plants. It is likely
Spelling Corner
1.
Sectional Exercise
Write ‘T’ for a true statement and ‘F’ for a false statement.
D
⑧
7
4
Cells, Human Reproduction and Heredity
C. Questions (7 marks)
E
EM
ST
1.
Bioprinting is a new technology that can be used to ‘print’ living tissues.
bio-ink
Sectional Exercise
bio-paper
(i) Bio-ink is added to a
layer of bio-paper.
(a)
(ii) Additional layers are
printed, one layer on
top of another.
(iii) Bio-ink fuses together
and the bio-paper is
dissolved.
(iv) A living tissue is
printed.
In bioprinting, bio-ink is used. What is contained in the bio-ink?
(1 mark)
see
Living cells (1m)
Integrated Exercise
(b)
Printing an organ is more difficult than printing a tissue. Why?
A tissue is made up of (i)
(3 marks)
the same type (1m)
(the same type/different
-
-
types) of cell while an organ is made up of (ii) - different types (1m)
(the same
type/different types) of tissues. Therefore, it is more (iii) complicated and difficult to print
.
gener
an organ than a tissue (1m)
(c)
Patients with severe skin damage (e.g. having burns) need to replace the damaged skin
with new skin. In the future, doctors can print the new skin with the bio-ink made from
Spelling Corner
the patient’s own skin cells. The flow chart below shows the key steps in obtaining
enough skin cells for making the bio-ink. Fill in the blanks.
1 Obtain the
patient’s
2 Allow them to
grow and
(3 marks)
3 Add chemicals to
make the cells
stem cells (1m) .
divide (1m)
differentiate (1m)
-
into more cells.
into skin cells.
Total Score :
bioprinting 生物打印技術
8
/ 15
Cells, Human Reproduction and Heredity
Heredity and variation
4.5
4
efer to Textbook
p.53–69
A. True or false (10 marks)
Write ‘T’ for a true statement and ‘F’ for a false statement.
⑮
T
2.
In a ‘genetic traits tree’, a square is commonly used to represent a male.
T
⑧
3.
Blood group is an example of continuous variation.
8
F
4.
A bar chart can be used to present the data of discontinuous variation.
5.
Some variations cannot be changed by the environment.
⑧
T
T
E
8.
T
(Normally, only one sperm can
&
F
Twins are formed by two sperms fusing with the same ovum. enter an ovum.)
F
Identical twins have the same IQ. (IQ is a continuous variation. It is determined
*
by both heredity and environment.)
⑧
There are four different kinds of bases on the DNA strands.
T
E
9.
If 20% of the bases on DNA is A, 20% of the bases is T.
E
10. Every three bases on DNA encode one ‘message’.
6.
7.
·
⑧
T
B. Multiple-choice (8 marks)
Choose the correct answer for each question.
1.
2.
Which of the following cells determine(s) the traits we inherit from our parents?
(1)
The sperm from the father
(2)
The ovum from the mother
(3)
The brain cells from both parents
A.
(1) only
B.
(3) only
C.
(1) and (2) only
D.
(2) and (3) only
C
⑤
Integrated Exercise
father and half from the mother.
Sectional Exercise
The zygote formed after fertilization receives half of its genetic information from the
Spelling Corner
1.
Which of the following variations in humans show(s) a continuous range of differences?
(1)
Height
(2)
Ear lobe
(3)
Foot length
A.
(1) only
B.
(2) only
C.
(1) and (3) only
D.
(2) and (3) only
C
⑤
15
4
Cells, Human Reproduction and Heredity
3.
The graph below shows the distribution of the body mass of a group of students.
Distribution of the body mass of a group of students
8
Sectional Exercise
6
Number of
students
4
2
0
44.5
47.5
50.5
53.5
56.5
59.5
Integrated Exercise
Body mass (kg)
According to the graph, what conclusion can be drawn?
4.
Spelling Corner
5.
A.
Students who have a body mass of 44.5–47.5 kg are abnormal.
B.
The largest number of students among the group have a body mass of 50.5–53.5 kg.
C.
Variation in the body mass of humans is clear-cut.
D.
The body masses of students is related to their diets.
B
3
Which of the following can be the causes of variations?
(1)
Differences in genetic materials
(2)
Cell division
(3)
Diet
A.
(1) and (2) only
B.
(1) and (3) only
C.
(2) and (3) only
D.
(1), (2) and (3)
B
S
Which of the following information can be used to prove whether two persons are identical
twins or not?
16
A.
Their genetic materials
B.
Their genders
C.
Their blood groups
D.
Their eye colours
⑧
A
4
Cells, Human Reproduction and Heredity
8.
They are of the same gender.
B.
Their genetic materials are the same.
C.
They result from a single zygote.
D.
Their body masses are the same.
D
8
Which of the following statements about DNA is INCORRECT?
A.
The structure of DNA was discovered several hundred years ago.
B.
DNA consists of two strands of bases.
C.
Base C on one strand always pairs with base G on the other.
D.
DNA is found inside the nucleus of a cell.
A
B
The sequence of bases on a DNA strand is ATGTTCCATGCG. Which of the following shows
the correct sequence of bases on the complementary strand?
A.
CGAABCTGCTAT
B.
CGAGGTTGCTAT
C.
TACAAGGTACGC
D.
TACAAGGTABAG
C
⑧
C. Fill in the blanks (10 marks)
1.
The features each generation inherits from their parents are called (a)
->
DNA
which are determined by the (b)
2.
3.
heredity
=>
histogram
-
We can draw a (a)
,
>
variations
,
in the nucleus of cells.
The differences in features among individuals of a species are called (a)
which are determined by (b)
>
->
traits
and the (c)
environment
=>
.
to present the data of continuous variation. On
the other hand, we can draw a (b)
bar chart
>
=>
to present the data of
discontinuous variation.
E
4.
The two strands of DNA are twisted around one another that makes DNA a
(a)
double helix
$5@°
. There are (b)
four
*
Sectional Exercise
E
7.
A.
Integrated Exercise
E
Which of the following statements about identical twins is INCORRECT?
Spelling Corner
6.
kinds of bases on the
strands and the sequence of the bases encodes instructions for cells to make
(c)
proteins
⑦
which have various functions in the body.
17
4
Cells, Human Reproduction and Heredity
D. Questions (27 marks)
1.
Study the ‘genetic traits tree’ below which shows whether different members in a family have
curved thumbs or straight thumbs.
I
1
2
Sectional Exercise
Key:
black = straight thumbs
II
white = curved thumbs
3
(a)
(b)
4
5
How many daughters does this family have?
(1 mark)
State the individuals who have straight thumbs in this family.
(1 mark)
⑳
Two e
(1m)
1, 3, 5 (1m)
⑤!.!...se
Integrated Exercise
(c)
(i)
Does the father or mother of this family have curved thumbs?
(1 mark)
Mother (1m)
⑧*⑦_
(ii)
Does the next generation inherit the trait of curved thumbs? If yes, state this
individual.
(2 marks)
Yes, (1m) individual 4 has curved thumbs. (1m)
-
(d)
Does the eldest child in this family have straight thumbs or curved thumbs?
(1 mark)
Straight thumbs (1m)
⑦****
Spelling Corner
2.
A group of students use a mobile phone app to measure their resting heart rate. The following
table shows the results.
Resting heart rate
(beats per minute)
Number of students
18
56–60 61–65 66–70 71–75 76–80 81–85 86–90 91–95
3
7
12
9
5
2
1
1
Cells, Human Reproduction and Heredity
(a)
4
Based on the data, explain whether heart rate is a continuous or discontinuous
variation.
(2 marks)
⑤°@°
Continuous variation, (1m) because it shows a continuous
range of differences. (1m)
--
(b)
Draw a histogram to present the data.
(5 marks)
Sectional Exercise
Distribution of resting heart rate of a group of students
12
10
Number
of
students
8
6
55.5 60.5 65.5 70.5 75.5 80.5 85.5 90.5 95.5
Resting heart rate (beats per minute)
E
3.
Correct title (1m)
Correct x-axis (1m)
Correct y-axis (1m)
Correct drawing of bars (2m)
The photo on the right shows a model in science. It is used to show the
structure of a material found in our body cells.
(a)
Write the full name of this material.
(1 mark)
Deoxyribonucleic acid (1m)
-
(b)
In which part of a cell is this material found?
X
(1 mark)
Inside the nucleus of a cell (1m)
(c)
This material is packed in some thread-like structures. Name these thread-like
structures.
(1 mark)
Chromosomes (1m)
(d)
What does X represent in this model?
Spelling Corner
2
Integrated Exercise
4
(1 mark)
Bases (1m)
-
(e)
This material is often described as ‘book of life’. Write ONE of its importance. (1 mark)
8⑧@xIt controls all the activities within our cells. (1m) / It determines the traits we inherit from our
parents. (1m) (Or any other reasonable answers)
19
Cells, Human Reproduction and Heredity
4
I NTEGRATED E XERCISE
A. True or false (8 marks)
Write ‘T’ for a true statement and ‘F’ for a false statement.
All plant cells contain chloroplasts. (Only the cells in green parts have chloroplasts,
F
2.
A light microscope usually has a higher magnification than an electron microscope.
F
3.
When making biological drawings, we should use a pencil to draw.
⑤
T
4.
An ovum carries 23 chromosomes.
T
&
5.
The zygote formed from fertilization carries two sets of chromosomes.
⑧
T
6.
Ovulation is a secondary sexual characteristic of females.
⑧
F
7.
Most of the genetic materials of a boy come from his father.
8.
Non-identical twins result from two different zygotes.
-
for example, leaves.)
F
T
Integrated Exercise
B. Multiple-choice (11 marks)
Choose the correct answer for each question.
1.
Sectional Exercise
:
1.
Which of the following structures contain(s) DNA?
P
Q
T
R
2.
Spelling Corner
S
A.
T only
B.
Q and T only
C.
P, Q and R only
D.
Q, S and T only
A
-
In the preparation of a microscope slide, the specimen should be as thin as possible so that
A.
light can pass through the specimen up into the objective.
B.
the cover slip can lie flat on the slide.
C.
it is easier to focus onto the specimen.
D.
it does not carry germs.
A
S
21
4
Cells, Human Reproduction and Heredity
3.
Sectional Exercise
Integrated Exercise
4.
Which of the following cells have the chromosomes shown in the photomicrograph?
A.
A male body cell
B.
A female body cell
C.
A male sex cell
D.
A female sex cell
How many times does a zygote divide to form a 16-cell embryo?
zygote
Spelling Corner
5.
B
D
A.
2 times
B.
3 times
C.
4 times
D.
5 times
16-cell embryo
C
g
The cells shown on the right are long and have many
branches. Which of the following is most likely the function
of these cells?
22
A.
To support the body
B.
To cover the surface of the body
C.
To store fats in the body
D.
To carry messages throughout the body
D
-
Cells, Human Reproduction and Heredity
6.
Organ X belongs to the
7.
A.
circulatory system.
B.
digestive system.
C.
reproductive system.
D.
breathing system.
B
-
The strawberries we buy in the market are selectively grown
for bigger size and sweeter taste. These strawberries have
8N chromosomes in their cells while wild strawberries only
Sectional Exercise
X
have 2N.
their cells, a cell of wild strawberries has
8.
A.
7 chromosomes.
B.
14 chromosomes.
C.
28 chromosomes.
D.
56 chromosomes.
B
⑧
Which of the following is NOT exchanged between the bloods of a foetus and its mother at
the placenta?
9.
A.
Red blood cells
B.
Oxygen
C.
Carbon dioxide
D.
Nutrients
A
⑧
Some stages of the birth of a baby are listed below.
(1)
The baby is pushed out.
(2)
The muscle of the uterus contracts strongly.
(3)
The placenta is expelled.
(4)
The amnion breaks.
Integrated Exercise
If regular strawberries have 56 chromosomes in each of
Spelling Corner
E
4
Which of the following is the correct order of these stages?
A.
(4)(2)(3)(1)
B.
(2)(4)(1)(3)
C.
(4)(2)(1)(3)
D.
(2)(4)(3)(1)
&
B
23
4
Cells, Human Reproduction and Heredity
Directions: Questions 10 and 11 refer to the graph below which shows how the thickness of the
uterine lining of a woman changes during a menstrual cycle.
Thickness of
the uterine
lining
ovulation
Sectional Exercise
1
7
21
28
35
Day of the cycle
10. During which period does the woman have menstruation?
A.
Day 1–5
B.
Day 10–15
C.
Day 15–20
D.
Day 20–25
A
Integrated Exercise
11. The length of the menstrual cycle of the woman is
A.
15 days.
B.
20 days.
C.
25 days.
D.
28 days.
D
C. Questions (31 marks)
Spelling Corner
1.
Fill in the blanks to complete the steps in using a microscope listed below. Then, arrange the
steps in the correct order.
(6 marks)
⑳@°π@°
stage (0.5m)
(a)
Place the slide on the
(b)
Place the microscope on a bench and near a
(c)
Turn the coarse adjustment knob in the opposite direction until you see a clear image.
(d)
Turn the
fine adjustment knob (0.5m)
_
⑰@π@
(e)
Turn the
coarse adjustment knob (0.5m)
=
#°@⑤I
(f)
Use a low-power eyepiece and a low-power (i)
Adjust the (ii)
Correct order:
24
14
B
b
mirror (0.5m)
=?

So
f

and hold it in place using the clips.
light (0.5m)
⑤°@5|
source.
to obtain the sharpest image.
until the objective is just above the slide.
.
-.
objective (0.5m)
for observation.
to obtain the most suitable brightness.
a
5

e

c

d
(3m)
Cells, Human Reproduction and Heredity
2.
4
The photomicrographs below are the images of some cells observed under a microscope.
Image I
(a)
Image II
Which image has a higher magnification?
(1 mark)
zen
Image II (1m)
(b)
(i)
If Image II is obtained using an eyepiece of 15X and an objective of 20X, what is
the magnification of the image?
(2 marks)
-
Sectional Exercise
Cell Y
see
(2 marks)
3 cm
(1m) = 0.01 cm (1m)
300
3.
X
The photo below shows a human foetus in the uterus.
(ii) umbilical cord (1m)
(i)
amnion (1m)
(iii)
placenta (1m)
(a)
Label the structures in the photo.
(3 marks)
(b)
A student wonders how the foetus ‘eats food’ and ‘goes to the toilet’ inside its mother’s
body. Briefly explain to her.
Spelling Corner
Measure and calculate the actual length of cell Y. Show your calculations clearly.
(ii)
Integrated Exercise
15 × 20 (1m) = × 300 (1m)
(3 marks)
The foetus develops in the uterus of its mother.
Through the (i)
gets (ii)
placenta (1m)
, it
nutrients and oxygen (1m)
from its mother's blood and gets rid of
(iii)
How does the foetus
eat food and go to
the toilet?
carbon dioxide and other wastes. (1m)
25
4
Cells, Human Reproduction and Heredity
Kate uses a paper to construct a DNA model as shown.
(a)
State TWO features of DNA shown by the paper model.
(2 marks)
Double helix (1m)
Complementary base pairing (1m)
The photo on the right shows a DNA model that is much
Integrated Exercise
(b)
more similar to real DNA. Compare this model with the
paper model. State TWO differences between them.
(2 marks)
->⑧
In this model, the strands and the bases are made up of smaller
units. (1m) There are spaces between the base pairs. (1m)
(Or any other reasonable answers)
(c)
Briefly explain the role of DNA in heredity.
(5 marks)
-
DNA encodes ‘messages’. These ‘messages’ depend on (i)
the sequence of bases (1m)
on DNA. These ‘messages’ are actually instructions for the cells
to make different types of (ii)
proteins (1m)
--
Sectional Exercise
5.
in the body, which have
various functions, such as used as structural materials of body tissues, or used as
Spelling Corner
E
hormones (1m)
that regulate cell activities. By controlling
---
enzymes and (iii)
>
->
(iv)
.
the types of proteins made, (1m) DNA can determine our traits (1m)
Total Score :
/ 50
27
5
ENERGY
5
Energy
S ECTIONAL E XERCISE
5.1 Basics of energy
Sectional Exercise
Integrated Exercise
Spelling Corner
30
efer to Textbook
p.79–87
A. True or false (5 marks)
Write ‘T’ for a true statement and ‘F’ for a false statement.
1.
The Sun gives out light energy and thermal energy.
R
T
2.
Batteries store electrical energy.
O
F
3.
Sound energy is given out when an object vibrates.
⑧
T
4.
The lower the position of an object, the more the potential energy it has.
higher
⑰.
One kJ is equal to 100 J.
F
8
5.
1000
=
F
⑧
B. Multiple-choice (4 marks)
Choose the correct answer for each question.
1.
2.
Which of the following statements about energy are correct?
(1)
We do not need energy when we are sleeping.
(2)
Plants need energy to grow.
(3)
Home appliances and machines in factories need energy to work.
A.
(1) and (2) only
B.
(1) and (3) only
C.
(2) and (3) only
D.
(1), (2) and (3)
C
8
Which of the following forms of energy is/are given out from a
burning candle?
(1)
Light energy
(2)
Chemical energy
(3)
Thermal energy
A.
(1) only
B.
(1) and (2) only
C.
(1) and (3) only
D.
(1), (2) and (3)
&
C
Energy
4.
Which of the following store(s) chemical energy?
(1)
Batteries
(2)
Fruits
(3)
Meat
A.
(1) only
B.
(1) and (2) only
C.
(1) and (3) only
D.
(1), (2) and (3)
D
⑨
Which of the following forms of energy is supplied from power stations and then transmitted
to our homes along power cables?
A.
Chemical energy
B.
Electrical energy
C.
Light energy
D.
Thermal energy
B
B
Sectional Exercise
3.
5
Look at the picture of Tom’s home below. Try to identify the forms of energy in the picture.
(9 marks)
Tom
(a)
The lamps and the television need
(b)
The television gives out (i)
(iii)
sound energy (1m)
=°?°>
electrical energy (1m)
-
light energy (1m)
*
⑳*
The dog has
(d)
The gas fuel stores
(e)
When the gas fuel burns, (i)
thermal energy (1m)
-
and
.
kinetic energy (1m)
->
(c)
, (ii)
to work.
Spelling Corner
1.
Integrated Exercise
C. Questions (9 marks)
when it runs.
chemical energy (1m)
°@°
°
.
thermal energy (1m)
>
and (ii)
light energy (1m)
⑰
are given out.
(f)
Tom is winding his toy car up. The wound-up spring in the toy car has
->⑤⑦.
potential energy (1m)
.
Total Score :
/ 18
gas fuel 氣體燃料
31
5
Energy
Energy conversion
5.2
efer to Textbook
p.88–101
A. True or false (4 marks)
Write ‘T’ for a true statement and ‘F’ for a false statement.
1.
When a ball falls to the ground, its potential energy is converted into kinetic energy.
2.
When we walk, the chemical energy stored in our bodies is converted into kinetic
Sectional Exercise
energy.
E
T
&
-
3.
Energy will be destroyed if we use it carelessly. (Energy cannot be destroyed.)
4.
A high-efficiency appliance uses more energy to do the same job than a low-efficiency
appliance.
T
8
less
-
F
8
F
8.
B. Multiple-choice (4 marks)
Choose the correct answer for each question.
Integrated Exercise
1.
Which of the following correctly describes the energy
conversion that takes place when a lamp is switched on?
2.
A.
chemical energy  electrical energy
B.
electrical energy  light energy + thermal energy
C.
chemical energy  light energy + thermal energy
D.
electrical energy  chemical energy
B
⑧
In the diagram below, the paper windmill spins when the water boils.
Spelling Corner
Which of the following correctly describes the energy conversion that takes place in the
above case?
32
A.
electrical energy  thermal energy  kinetic energy
B.
thermal energy  electrical energy  potential energy
C.
electrical energy  chemical energy  kinetic energy
D.
chemical energy  thermal energy  potential energy
A
⑤.
5
Energy
C. Questions (21 marks)
1.
Write the energy conversion in each of the following cases.
(8 marks)
(a)
When plants make their own food using sunlight,
light energy (1m)
chemical
energy (1m)
⑰

(from the Sun)
Sectional Exercise
(b)
(stored in the plants)
When the stretched bow string is released,
potential energy (1m)
kinetic energy (1m)

⑦
(stored in the bow string)
(c)
(of the arrow)
When the match is lit,
Integrated Exercise
chemical energy  thermal energy + light energy (0.5m)
↳
⑮
(1m)
(0.5m)
=?.
(stored in the match)
(d)
When the bowling ball rolls and knocks down the bowling
pins,
kinetic energy (1m)  kinetic energy
+ sound energy (0.5m)
>
(0.5m)
Spelling Corner
(of the bowling ball)
X
E
2.
(of the bowling pins)
The photos below show two electrical appliances.
Doorbell
34
Electric toothbrush
5
Energy
I NTEGRATED E XERCISE
A. True or false (8 marks)
Write ‘T’ for a true statement and ‘F’ for a false statement.
Sectional Exercise
Integrated Exercise
Spelling Corner
44
1.
A bow string stores potential energy when it is released.
2.
The electrical energy supplied to a lamp is all converted into light energy.
F
When a ball is falling down, its kinetic energy increases.
T
3.
4.
5.
6.
7.
E
8.
F
I
stretched
↳
converted
into light energy and thermal energy
Electrical energy cannot be converted into potential energy. (All forms of energy can be
F
Copper conducts heat faster than wood.
T
converted into any other form.)
Only convection and radiation take place in gases. (Conduction can also take place
F
Radiation can take place in a vacuum.
T
All renewable energy sources do not pollute the environment.
F
in gases.)
(Renewable energy sources cause relatively less pollution than non-renewable energy sources.)
B. Multiple-choice (10 marks)
Choose the correct answer for each question.
1.
Leo uses a lift to travel to the upper floor. Which of the following
descriptions is correct when the lift goes upwards?
2.
A.
Leo and the lift gain potential energy.
B.
Only the lift gains potential energy.
C.
Leo gains potential energy and the lift gains kinetic energy.
D.
Leo and the lift lose potential energy.
A
IB
Compare the kinetic energy of the following objects.
(1)
A 15 000 kg bus travelling at 30 km/h
(2)
A 15 000 kg bus that is not moving
(3)
A 2000 kg car travelling at 30 km/h
Arrange the objects in the order of increasing kinetic energy.
A.
(1), (2), (3)
B.
(2), (1), (3)
C.
(2), (3), (1)
D.
(3), (2), (1)
⑤
C
Energy
3.
5
Which of the following can convert chemical energy into kinetic energy?
(1)
A flying bird
(2)
A launching rocket
(3)
A moving solar
(1) and (2) only
B.
(1) and (3) only
C.
(2) and (3) only
D.
(1), (2) and (3)
A
&
energy and potential energy that the ball has at different times.
At the beginning,
Energy
Key:
kinetic energy
potential energy
sound energy
Integrated Exercise
A ball falls to the ground and then bounces. The bar charts below show the amount of kinetic
When the ball bounces up,
Spelling Corner
4.
A.
Sectional Exercise
powered car
?
Which of the following bar charts best shows the energies when the ball bounces up?
A.
Energy
B.
Energy
C.
D.
Energy
Energy
B
D
45
5
Energy
(b)
The picture below shows a hanging metal spiral. Why does the spiral spin when the
candle is lit?
(1 mark)
Sectional Exercise
This is because the hot air rises and a convection current is set up. (1m)
EM
ST
2.
The design of a steam powered toy boat is shown below.
Integrated Exercise
The candle is used to heat the
water in the copper pipe. When
the water boils and turns into
steam, the steam forces water
out of the ends of the pipe and
drives the boat forwards.
The copper pipe is filled with water.
(a)
Fill in the boxes below to show the energy conversions that take place in the boat.
(5 marks)
Spelling Corner
chemical (1m)
thermal (1m)
kinetic (1m) + thermal (1m)
kinetic (1m)
-
(b)
energy
energy
(stored in the
candle)
(of the candle
flame)
energy
energy
(of the steam)
energy
(of the boat)
State the process by which heat is transferred from the candle flame to the copper
pipe.
(1 mark)
Convection (1m) / Convection and radiation (1m)
(c)
Which material, copper or glass, is more suitable for making the pipe? Explain your
answer.
(2 marks)
Copper. (1m) It is a better conductor than*
glass so that heat can be transferred to the water more
⑤°@π@°
°⑧
effectively. (1m)
48
5
Energy
Alan has made a solar cooker as shown below.
glass cover
plastic box
(i)
Why does Alan use a box made of plastic?
(2 marks)
Plastic is a poor conductor of heat (1m) and helps reduce heat loss by conduction. (1m)
(ii)
Why does he use a cover made of glass?
(1 mark)
Glass can help trap heat from the Sun inside the solar cooker. (1m)
(b)
Alan wants to investigate how the angle of incoming sunlight affects the performance of
Sectional Exercise
(a)
food is put in this bowl
the solar cooker. He measures the time it takes to cook an egg in the solar cooker for
different angles. His experimental results are shown in the table.
Sun
Angle of incoming sunlight
to the solar cooker
Time taken to cook an
egg (min)
30°
78
60°
54
90°
37
Sun
Sun
solar
cooker
30° 60°90°
Integrated Exercise
3.
In Alan’s investigation,
(i)
name the independent variable.
(1 mark)
Angle of incoming sunlight to the solar cooker (1m)
-
(ii)
list a controlled variable.
(1 mark)
The size of the egg (1m)
-
(iii)
what can be concluded from Alan’s result?
(2 marks)
The solar cooker has the highest efficiency when
to the solar cooker is 90° (2m)
(c)
Spelling Corner
EM
ST
the angle of incoming sunlight
.
Suggest ONE improvement in the design of Alan’s solar cooker to increase its efficiency.
Explain your answer.
(2 marks)
Paint the inner surface of the solar cooker black (1m) because black surface is a good absorber of
radiation. (1m) (Or any other reasonable answers)
49
6
MATTER AS PARTICLES
6
Matter as Particles
S ECTIONAL E XERCISE
6.1 Particle theory
Sectional Exercise
A. True or false (5 marks)
Write ‘T’ for a true statement and ‘F’ for a false statement.
Integrated Exercise
1.
All matter is made up of particles.
T
⑧
2.
Air has mass.
T
&
3.
There are different types of particles.
T
⑧
4.
Different particles have the same size but different masses.
F
⑧
5.
A molecule cannot be separated into smaller particles.
F
⑧
B. Multiple-choice (7 marks)
Choose the correct answer for each question.
1.
Which of the following are matter?
(1) Air
Spelling Corner
2.
54
efer to Textbook
p.143–159
(2) Sound
(3) Cloud
A.
(1) and (2) only
B.
(1) and (3) only
C.
(2) and (3) only
D.
(1), (2) and (3)
B
⑧
Which of the following statements about the particle theory are correct?
(1)
There are empty spaces between particles.
(2)
Particles are moving all the time.
(3)
Particles are very small.
A.
(1) and (2) only
B.
(1) and (3) only
C.
(2) and (3) only
D.
(1), (2) and (3)
D
⑧
Matter as Particles
3.
6
A smoke particle P travels in a zigzag path in air as shown on
the right. Which of the following statements best explains the
motion of P?
B.
P is pushed randomly by air particles.
C.
P is larger than air particles.
D.
P can move in a zigzag path on its own.
8
B
One of the main points of the particle theory is that there are empty spaces between
particles. Which of the following results of experiments provide(s) evidence supporting this
main point?
We can smell the perfume contained in a balloon.
(2)
When water and alcohol are mixed, the total volume of the liquids will decrease.
A.
(1) only
B.
(2) only
C.
(1) and (2) only
D.
None of the above
C
S
Which of the following diagrams best shows a water molecule?
A.
B.
C.
D.
Integrated Exercise
5.
(1)
A
⑤
6.
Sectional Exercise
P is heavier than air particles.
Spelling Corner
4.
P
A.
Which of the following statements about atoms or molecules is/are correct?
(1)
An atom is the ‘smallest’ unit of matter.
(2)
A molecule consists of at least two atoms.
(3)
Iron is made up of iron molecules.
A.
(1) only
B.
(1) and (2) only
C.
(2) and (3) only
D.
(1), (2) and (3)
B
I
55
6
Matter as Particles
E
7.
How many atoms does a carbon dioxide molecule (chemical formula: CO2) consist of?
A.
1
B.
2
C.
3
D.
4
C
⑧
C. Fill in the blanks (6 marks)
Sectional Exercise
1.
All matter has two properties: it has (a)
2.
Pollen grains move (a)
randomly
--
An
4.
A
atom
and it takes up (b)
space
-
.
on their own in still water. The motion of the
Brownian motion
-
pollen grains is called (b)
3.
mass
.
is the basic type of particle making up matter.
molecule
-
consists of two or more atoms joined together.
D. Questions (10 marks)
Integrated Exercise
1.
Complete the following figure which summarizes the main points of the particle theory.
(4 marks)
All matter is made up of
-
Particles are very small.
(a) particles (1m) .
-
There are (b) empty spaces (1m)
between particles.
Spelling Corner
PARTICLE
THEORY
(d) Different particles have different
all the time.
2.
W
->
(c) different (1m)
u particles.
⑳
Particles are moving
E
sizes and masses. (1m)
Write down the chemical formula for each of the following molecules.
(a)
(b)
O
C
CO2 (1m)
56
Different matter is made up of
O
(3 marks)
(c)
O
O
O2 (1m)
H
O
H
H2O (1m)
Matter as Particles
3.
6
Joseph had a barbecue with his family. When he returned
home, he found his clothes still had the barbecue smell.
Explain this briefly based on the particle theory. (3 marks)
=>
When the charcoal burns, some of its (a)
go into the air. They (b)
particles (1m)
move randomly (1m)
in
-
-.
Therefore, the clothes still had the
barbecue smell.
Total Score :
Particle model for the three states of matter
6.2
/ 28
efer to Textbook
p.160–167
Sectional Exercise
the air and some of them (c) stick onto Joseph’s clothes. (1m)
1.
Gases have fixed volume.
F
⑨
2.
The particles in a gas are far apart.
3.
The particles in solids can only vibrate about fixed positions.
⑧
4.
From the particle model, the molecules of water are close together and cannot move
T
F
around each other.
5.
T
When a gas is compressed, its particles decrease in size.
8
F
B. Multiple-choice (4 marks)
Choose the correct answer for each question.
1.
Which of the following substances is/are solid(s)?
(1) Honey
(2) Sand
A.
(2) only
B.
(3) only
C.
(1) and (2) only
D.
(2) and (3) only
(3) Ice cream (in a freezer)
Spelling Corner
Write ‘T’ for a true statement and ‘F’ for a false statement.
Integrated Exercise
A. True or false (5 marks)
D
8
57
6
Matter as Particles
2.
3.
Scientists classify matter as a solid, a liquid or a gas based on
A.
whether it is transparent.
B.
whether it has mass.
C.
whether it has fixed shape and fixed volume.
D.
whether it can be seen with the naked eye.
Which of the following statements about the particle models of solids, liquids and gases
Sectional Exercise
is correct?
4.
A.
The particles in gases have equal distances from any other particles.
B.
The particles in liquids are close together.
C.
The particles in solids can move around freely.
D.
The particles in solids stay at rest.
S
B
In an experiment, the air in a syringe can be compressed as
shown on the right. This experiment shows that
Integrated Exercise
(1)
air particles are far apart.
(2)
air particles can move freely in all directions.
(3)
air particles have mass.
A.
(1) only
B.
(2) only
C.
(1) and (2) only
D.
(1) and (3) only
plunger
push
air
A
③
C. Fill in the blanks (3 marks)
-: solid, (b)-and gas.
Spelling Corner
1.
Matter can exist in three (a)
2.
The
states
liquid
particle model
describes the arrangements and movements of
the particles in solids, liquids and gases.
D. Questions (20 marks)
1.
Complete the table below to compare the properties of a solid, a liquid and a gas. (8 marks)
Solid
Does it have mass?
Does it have fixed volume?
Does it have fixed shape?
transparent 透明
58
C
D
yes
Liquid
Gas
yes (1m)
yes (1m)
--
no (1m)
en
yes (1m)
no (1m)
no (1m)
---
yes (1m)
--
yes (1m)
-
Matter as Particles
2.
6
We can make an analogy between the behaviours of particles in different states of matter and
the behaviours of students in a school. In the following groups of students, each student
Group P
Group Q
Group R
Having a P.E. lesson
During a lesson
During recess
State of matter
represented
(a)
gas (1m)
->
Distance between
particles
(d)
far apart (1m)
-
Arrangement of
particles
(f)
irregular (1m)
->
Motion of particles
Group Q
(b)
Group R
(c)
solid (1m)
-
--
(e) closely packed (1m) closely packed
regular
(g)
get
(h) free to move in all
directions (1m)
liquid (1m)
=>
(i) vibrate about fixed
positions (1m)
irregular (1m)
move around each
other
Integrated Exercise
Group P
Draw the arrangements of particles in a solid, a liquid and a gas in the boxes below. (3 marks)
(a) solid
(b) liquid
-.
-.
.
.
Learn
(c) gas
(1m)
.
.
ne
a
8(1m)
-
8.
(1m)
Total Score :
/ 32
Spelling Corner
3.
(9 marks)
Sectional Exercise
represents a particle. Complete the table below to make the analogy.
analogy 比擬
59
6
Matter as Particles
Dissolving
6.3
efer to Textbook
p.168–173
A. True or false (3 marks)
Write ‘T’ for a true statement and ‘F’ for a false statement.
1.
After sugar has completely dissolved in water, the sugar particles spread out evenly in
T
D
the solution formed.
Sectional Exercise
2.
When sugar dissolves in water, the volume of the sugar solution formed is slightly less
·
than the total volume of the sugar and water before dissolving.
3.
T
Mass is not conserved in dissolving.
F
B. Multiple-choice (3 marks)
Choose the correct answer for each question.
1.
Some salt crystals has dissolved in water. Which of the following statements about the
Integrated Exercise
dissolving are correct?
2.
(1)
The salt particles change from the solid state to the liquid state.
(2)
The salt particles separate and mix with the water particles.
(3)
The total number of the salt particles remains unchanged.
A.
(1) and (2) only
B.
(1) and (3) only
C.
(2) and (3) only
D.
(1), (2) and (3)
C
&
In an experiment, a purple crystal of a salt is put into water. Upon gentle stirring, the crystal
dissolves after five minutes and a purple solution is formed.
Spelling Corner
water
purple solution
crystal
beginning
after five minutes
Which of the following statements can be concluded from this experiment?
(1)
The salt particles and water particles have different sizes.
(2)
The salt particles spread out evenly in the solution after the dissolving.
(3)
The number of the salt particles remains unchanged during the dissolving.
A.
C.
60
=
>
(2) only
B.>
(1) and (2) only
>
(The solution has a paler colour than the crystal, but this is not enough to conclude (3).)
(1) and (3) only
D.
(2) and (3) only
A
Matter as Particles
The figure on the right shows the arrangement of particles
sugar particle
in a sugar solution. Which of the following statements
(1)
The sugar particles vibrate about fixed positions in the cup.
(2)
The water particles can move around other particles in the cup.
(3)
The sugar particles will move down and eventually stay at the bottom of the cup.
A.
(2) only
B.
(3) only
C.
(1) and (3) only
D.
(2) and (3) only
A
-
C. Fill in the blanks (4 marks)
When sugar (a)
=>
>
mix
(c)
2.
dissolves
Mass is
in water, the sugar particles (b)
separate
=>
and
with the water particles. A sugar solution is formed.
conserved
=>
(which means remain unchanged) in dissolving.
Integrated Exercise
1.
D. Questions (6 marks)
1.
In an experiment, 30 g of salt is added to some water. The water
is then stirred until the salt has dissolved in the water completely.
salt
The solution formed has a mass of 280 g.
(a)
What is the mass of the water before the salt is added?(1 mark)
Mass = 280 g – 30 g = 250 g (1m)
(b)
water
Name the instrument that can be used to measure the mass of
a solution in the laboratory.
(1 mark)
re
Electronic balance (1m)
2.
stir
In an experiment, some sugar is dissolved in water. The volume of
the solution decreases slightly in dissolving. Explain this using the
particle theory.
-
particles. Water particles are (b)
me
-a
. Therefore,
the volume decreases slightly (1m)
water
than
sugar particles and (c) fit into the spaces between the sugar particles (1m)
(d)
glass rod
(4 marks)
particle theory (1m)
, there are spaces between
ene
smaller (1m)
From the (a)
Sectional Exercise
water particle
about the particles is/are correct?
Spelling Corner
3.
6
sugar
in dissolving.
Total Score :
/ 16
61
6
Matter as Particles
Thermal expansion and contraction
6.4
efer to Textbook
p.174–180
A. True or false (3 marks)
Write ‘T’ for a true statement and ‘F’ for a false statement.
Sectional Exercise
1.
When a substance is heated, its particles will increase in size.
2.
The speeds of particles in a substance depend on the temperature of the substance.
3.
When particles in a substance move slower, they will become closer together.
T
T
B. Fill in the blanks (5 marks)
1.
I
expand
on heating and (b)
thermal expansion and contraction
-and (b)
(a)
contract
on cooling. This is
-
->
Most substances (a)
called (c)
2.
Thermometers
fire sprinklers
-
.
work by making use of
Integrated Exercise
thermal expansion and contraction.
C. Multiple-choice (3 marks)
Choose the correct answer for each question.
1.
A statue heats up under the Sun. Which of the following
will increase when the statue heats up?
Spelling Corner
2.
(1)
Mass of the statue
(2)
Volume of the statue
(3)
Number of particles in the statue
A.
(1) only
B.
(2) only
C.
(1) and (2) only
D.
(2) and (3) only
B
i
Which of the following statements about the particles in the three states of matter are correct?
(1)
When a gas is heated, its particles become further away from each other.
(2)
When a liquid is cooled, its particles move slower.
(3)
When a solid is cooled, its particles become smaller.
A.
(1) and (2) only
B.
(1) and (3) only
C.
(2) and (3) only
D.
(1), (2) and (3)
statue 雕像
62
:
F
A
&
6
Matter as Particles
Which of the following is/are example(s) of thermal expansion and contraction?
(1)
(2)
(3)
dented
ping-pong ball
metal lid
A dented ping-pong ball
A
beaker
will
break
A tight metal lid can be
restores its shape in hot
if washed immediately
removed more easily by
water.
after heating.
putting it in hot water.
A.
(1) only
B.
(1) and (2) only
C.
(2) and (3) only
D.
(1), (2) and (3)
D
⑧
D. Questions (9 marks)
A toy is shown on the right. When we are holding the lower
chamber of the toy, the liquid inside will rise and fill the upper
chamber. Briefly explain why.
upper chamber
Integrated Exercise
1.
Sectional Exercise
3.
(4 marks)
When we are holding the lower chamber, the air inside
-
(a)
. The air particles inside
is heated up (1m)
(b)
and become
move faster (1m)
(c)
(d)
expands (1m)
lower chamber
. As a result, the air
further apart (1m)
liquid
and pushes the liquid to the upper
2.
(a)
Using the particle theory, explain what will happen to the size of a substance when its
temperature decreases.
(3 marks)
>
When temperature decreases, the particles of the substance (i)
-and
become (ii)
As a result, the substance will (iii)
(b)
will move slower (1m)
.
closer together (1m)
decrease in size (1m)
Overhead power lines need to be left slack when they are
.
Spelling Corner
chamber.
overhead power lines
installed. Explain this from the point of view of thermal
expansion and contraction.
(2 mark)
This is aimed at preventing the power lines from
-
(i)
breaking (1m)
in cold weather.
when they (ii)
contract (1m)
Total Score :
/ 20
slack 鬆弛
63
6
Matter as Particles
Gas pressure
6.5
E x te n s
ion
efer to Textbook
p.181–192
A. True or false (3 marks)
Write ‘T’ for a true statement and ‘F’ for a false statement.
Sectional Exercise
1.
Gas particles can move freely in all directions.
T
⑧
2.
When temperature increases, gas particles move faster.
T
&
3.
We cannot feel atmospheric pressure because it is too small to be sensed by our
bodies.
B. Multiple-choice (3 marks)
Choose the correct answer for each question.
1.
Which of the following objects make(s) use of gas pressure?
(1) Inflated football
Integrated Exercise
Spelling Corner
2.
3.
64
⑧
F
(2) Suction cup
(3) Aerosol can
A.
(1) only
B.
(1) and (3) only
C.
(2) and (3) only
D.
(1), (2) and (3)
D
&
Which of the following statements about gas pressure is/are correct?
(1)
Gas pressure increases with the temperature of the gas.
(2)
Gas pressure increases with the volume of the gas.
(3)
Gas pressure increases with the number of particles in the gas.
A.
(1) only
B.
(1) and (3) only
C.
(2) and (3) only
D.
(1), (2) and (3)
⑰
B
When a gas is compressed,
(1)
its gas particles become smaller.
(2)
its gas particles hit the container walls more frequently.
(3)
the gas pressure decreases.
A.
(2) only
B.
(1) and (2) only
C.
(1) and (3) only
D.
(2) and (3) only
B
A
6
Matter as Particles
C. Fill in the blanks (9 marks)
=>
When the temperature of a gas increases, the gas particles move (a)
hit the container walls (b)
and (c)
harder
faster
more frequently
. They
. As a result,
·.
3.
increases
The Earth is surrounded by a layer of air called the (a)
Earth are (b)
atmosphere
. When objects on the
E
hit
by the air particles in the atmosphere, a pressure is produced.
-
--
This pressure is called the (c)
atmospheric pressure
or (d)
.
air pressure
D. Questions (17 marks)
1.
An air lounger is a bag filled with air. When the air lounger is inflated, people can sit on it
like sitting on a chair. Explain this using the particle theory.
(3 marks)
air lounger
&188Bre
The (a)
(b)
gas pressure (1m)
-
- is produced. This gas pressure (c)
of the people sitting on it.
weight (1m)
2.
inside the air lounger hit the walls of the lounger and
air particles (1m)
supports the body
The existence of atmospheric pressure can be shown
using the Magdeburg hemispheres. The steps are shown
below. Arrange the steps in the correct order. (2 marks)
I.
Sectional Exercise
the gas pressure (d)
Integrated Exercise
2.
Gas pressure
is produced when gas particles hit the walls of the container.
-
Spelling Corner
1.
Hold the hemispheres together and turn on the
pump to remove the air inside.
II.
Connect the hemispheres to a vacuum pump.
III.
Try to pull the two hemispheres apart.
IV.
Close the valve and disconnect the hemispheres from the pump.
Correct order:
8
II
I
 
Magdeburg hemispheres
IV  III
(2m)
8
existence 存在
65
6
Matter as Particles
3.
An experiment is set up as shown below. What will happen to the balloon when the vacuum
pump is switched on? Explain your answer using the particle theory.
(6 marks)
to vacuum
pump
Sectional Exercise
balloon
bell jar
-
air (1m)
fewer air particles hitting the wall of the bell jar (1m)
is drawn out of the bell jar. There are (c) -
The balloon will (a)
expand (1m)
. When the vacuum pump is switched on, (b)
Integrated Exercise
Alte
(d)
decreases (1m)
so the gas pressure in the bell jar
larger (1m)
---
. As a result, the air pressure inside the balloon is (e)
expands (1m)
.
Atte
than that outside and the balloon (f)
4.
Glass suction lifters are usually used to hold a piece of glass. When we use a suction lifter,
we need to pull its handle down as shown below. The rubber sheet of the suction lifter will
then move up and the suction lifter will attach to the glass firmly.
handle
pull
Spelling Corner
glass
suction lifter
glass
rubber sheet
rubber sheet is
lifted up
Using the particle theory, explain how a glass suction lifter works.
(6 marks)
under the suction lifter increases. The air particles inside (b)
- the
walls of the suction lifter (c)
-so the air pressure inside
(d)
-. As a result, the air pressure inside is (e)When the handle is pulled down, the rubber sheet is moved up and the (a)
volume (1m)
hit (1m)
less frequently (1m)
decreases (1m)
nepushes the suction lifter to
that outside and (f)
the glass firmly.
66
lower than (1m)
the air pressure outside (1m)
Total Score :
/ 32
Matter as Particles
Density
6.6
6
efer to Textbook
p.193–210
A. True or false (5 marks)
Write ‘T’ for a true statement and ‘F’ for a false statement.
2.
If an iron is divided into two smaller pieces, each piece of iron has a lower density
Meet
F
&
than the original iron. (The smaller piece of iron has the same density as the original iron.)
F
D
3.
Ice has a lower density than water.
T
④
4.
Oil floats on top of water because oil is lighter than water.
F
⑧
5.
The density of air increases with its temperature.
F
8
B. Multiple-choice (5 marks)
Sectional Exercise
If two objects have the same volume, they must have the same mass.
1.
2.
Which of the following is/are the unit(s) of density?
(1)
g/cm3
(2)
cm3/g
(3)
kg/m3
A.
(1) only
B.
(3) only
C.
(1) and (3) only
D.
(2) and (3) only
C
8
The masses and volumes of four objects are shown below. Which object has the highest
density?
3.
Mass
Volume
A.
10 g
10 cm3
B.
20 g
40 cm3
C.
30 g
20 cm3
D.
40 g
30 cm3
&
C
The density of silver is 10.5 g/cm3. What is the volume of a silver
ring if its mass is 2.1 g?
4.
A.
0.2 cm3
B.
C.
10.5 cm3
D. 22.5 cm3
Integrated Exercise
Choose the correct answer for each question.
Spelling Corner
E
1.
5 cm3
A
S
In the set-up on the right, X and Z are liquids while
Y is a solid. Y floats in Z but sinks in X. Arrange X, Y and Z in
ascending order of density.
liquid X
A.
X, Y, Z
B.
C.
X, Z, Y
D. Y, Z, X
solid Y
Z, Y, X
A
⑧
liquid Z
67
6
Matter as Particles
E
5.
Which of the following statements best explains why hot air rises and cold air sinks?
A.
Air particles move faster in hot air than in cold air.
B.
The pressure of hot air is larger than that of cold air.
C.
Air particles in hot air are lighter than the air particles in cold air.
D.
Hot air has lower density than cold air.
D
&
C. Fill in the blanks (6 marks)
Sectional Exercise
1.
--Density
(a)
is the (b)
mass
2
substance. Its unit is g/cm3 or kg/m3.
2.
Whether an object floats or sinks in a liquid depends on (a)
act
(b)
floats
(c)
sinks
volume
per unit (c)
density
. An object
in a liquid if its density is lower than that of the liquid. An object
in a liquid if its density is higher than that of the liquid.
Integrated Exercise
D. Questions (18 marks)
1.
Paul is finding the density of a cork. He first measures the mass of the cork with a balance.
Then, he ties the cork to a metal block with a thread, and puts them into a measuring cylinder
of water to measure the volume of the cork as shown below.
3
3
cmcm
cork
Spelling Corner
(a)
cm3
100100
100
90 90
90
80 80
80
70 70
cork
3
3
cmcm
cm3
3
3
cmcm
cm3
100100
100
100100
100
90 90
90
90 90
90
80 80
80
80 80
80
70
70 70
70
70 70
70
60 60
60
60 60
60
60 60
60
50 50
50
50 50
50
50 50
50
40 40
40
40 40
40
40 40
40
30 30
30
30 30
30
30 30
30
20 20
20
20 20
20
20 20
20
10 10
10
10 10
10
10 10
10
thread
metal
block
Find the volume of the cork.
(2 marks)
Volume = 90 cm3 – 70 cm3 (1m) = 20 cm3 (1m)
(b)
Find the density of the cork.
(c)
(2 marks)
=>
tee
Density =
mass
15 g
=
(1m) = 0.75 g/cm3 (1m)
volume
20 cm3
Why does Paul need to tie the cork to a metal block before putting it into the water?
-
The cork (i)
(ii)
68
of a
floats (1m)
(2 marks)
in water. After it is tied to the metal block, it
can be fully immersed into the water (1m)
.
Matter as Particles
2.
Steel is denser than sea water but steel ships can float in the sea. Why?
6
(3 marks)
The body of a steel ship contains a large volume of (a)
(b)
much less dense (1m)
below.
(2 marks)
&
E
EM
ST
4.
outside (1m)
A student has made a revolving lantern, as shown below. It is a lamp with its lampshade
joined to some blades. When the lamp is switched on, the lampshade will rotate.
blade
lampshade
(a)
Explain how the lantern works.
(6 marks)
-the air in the lantern, the air particles
heats up (1m)
When the lamp (i)
-
(ii)
the
(v)
density
of
the
air
inside
(iv)
lower than the density of the air (1m)
. Therefore,
further apart (1m)
decreases (1m)
and
become
in the surroundings. As a result,
-
the hot air (vi)
(b)
and become (iii)
move faster (1m)
Integrated Exercise
inside (1m)
Sectional Exercise
Draw the arrangements of air particles inside and outside the hot air balloon in the boxes
Spelling Corner
3.
overall density of the ship is
than the density of sea water. As a result, the steel ship can float in the sea.
lower (1m)
E
than sea water. Thus, the (c)
, which is
air (1m)
.
rises and turns the blades of the lampshade (1m)
Why is it needed to leave enough space under the lampshade?
The space allows the air in the surroundings
are.
(1 mark)
to flow into the lampshade from
the bottom (1m)
revolving lantern 走馬燈
lampshade 燈罩
Total Score :
/ 34
blade 扇葉
69
6
Matter as Particles
I NTEGRATED E XERCISE
A. True or false (10 marks)
Write ‘T’ for a true statement and ‘F’ for a false statement.
1.
A molecule is the ‘smallest’ unit of matter.
Sectional Exercise
Integrated Exercise
Spelling Corner
70
3.
During dissolving, both volume and mass are conserved.
4.
When sugar dissolves in water, the sugar particles separate and mix with the water
F
F
particles.
T
5
5.
When a solid is heated, its particles become bigger and therefore the solid expands.
F
D
6.
A thermometer works by making use of thermal expansion and contraction of the
liquid contained in the thermometer.
:
T
E
7.
There is no air pressure in space.
E
8.
The higher the temperature of a gas, the larger the gas pressure.
9.
If an object is heavy enough, it sinks in water.
E
F
.
(Particles in a liquid
2. Particles in a liquid move randomly only in the horizontal direction. cannot move freely
in all directions like those in a gas, but they can move randomly in all directions within the liquid.)
.
T
T
F
10. When a gas is heated, its density will increase.
F
B. Multiple-choice (10 marks)
Choose the correct answer for each question.
1.
2.
Which of the following statements about molecules and atoms is/are correct?
(1)
A molecule consists of at least two different kinds of atoms.
(2)
The molecules in a gas cannot move freely but the atoms in a gas can.
(3)
An oxygen molecule has a larger size than an oxygen atom.
A.
(1) only
B.
(3) only
C.
(1) and (2) only
D.
(2) and (3) only
B
B
Sam is having lunch in a restaurant. He can smell
the food served on another table. This shows that
A.
particles are moving all the time.
B.
there are spaces between particles.
C.
different particles have different sizes.
D.
different matter is made up of different particles.
A
8
Matter as Particles
3.
6
Robert Brown proposed that pollen grains were alive so they performed Brownian motion in
water. He conducted similar experiments using coal powders, glass powders and metal
metal powders
Which of the following statements can be concluded from the results?
4.
(1)
Any powders can perform Brownian motion.
(2)
Coal, glass and metal powders are alive.
(3)
Being alive is not the reason why pollen grains perform Brownian motion.
A.
(1) only
B.
(1) and (2) only
C.
(1) and (3) only
D.
(2) and (3) only
⑤
C
The arrangements of particles in two different states of matter are shown below.
State X
State Y
What are states X and Y?
5.
State X
State Y
A.
Solid
Gas
B.
Solid
Liquid
C.
Liquid
Gas
D.
Liquid
Solid
Integrated Exercise
glass powders
C
8
Spelling Corner
coal powders
Sectional Exercise
powders. The results were as follows.
When salt dissolves in water, which of the following quantities will increase?
(1)
Total mass of the salt and water
(2)
Total volume of the salt and water
(3)
Density of the solution
A.
(2) only
B.
(3) only
C.
(1) and (3) only
D.
(2) and (3) only
B
⑤
71
6
Matter as Particles
6.
A rock in a desert could break apart when weathering occurs.
Sectional Exercise
Which of the following statements best explains this phenomenon?
A.
The atmospheric pressure exerts a strong force on the rock.
B.
The inside of the rock has a higher density than the surface of the rock.
C.
The mass of the rock increases over time due to absorption of sunlight.
D.
The rock expands and contracts repeatedly due to temperature differences between
Integrated Exercise
E
7.
As shown below, the plunger of a syringe is pushed inwards.
plunger
syringe
push
In the process, which of the following combinations about the air in the syringe is correct?
Spelling Corner
E
8.
Volume
Density
Pressure
A.
Decreases
Unchanged
Increases
B.
Decreases
Increases
Increases
C.
Decreases
Increases
Decreases
D.
Increases
Decreases
Decreases
B
08
Which of the following statements explains why an aerosol can should not be placed under
sunlight?
A.
The can may melt when absorbing heat from the sunlight.
B.
The can may become so hot that we will get a heat burn when touching it.
C.
The liquids inside the can will evaporate faster.
D.
The gas pressure inside the can will increase and explosion may occur.
weathering 風化
72
D
⑧
days and nights.
⑧
D
Matter as Particles
9.
6
A balloon contains a gas of density 1.2 kg/m3 and is rising
in air. If its volume becomes double at a particular height,
what is the density of the gas inside?
A.
0.6 kg/m3
B.
1.2 kg/m3
C.
1.8 kg/m3
D.
2.4 kg/m3
A
⑪
inside a gas jar. Which of the following statements about
cork
.
8
(1)
(The wood could be
lighter (but denser)
The wood is heavier than the cork. than the cork.)
(2)
The mercury has the highest density among all the
oil
wood
water
iron
mercury
substances.
The iron has a higher density than the oil.
A.
(2) only
B.
(1) and (2) only
C.
(2) and (3) only
D.
(1), (2) and (3)
⑨
C
C. Questions (30 marks)
1.
Which of the following are matter? Write a ‘✓’ in the appropriate box(es).
(2 marks)
(Note: One mark would be deducted for each wrong answer.)
a
c
b
Rainbow
Smoke
e
d
Flower
✓ (0.5m)
·De
Da
✓ (0.5m)
↳
Jelly
✓ (0.5m)
⑧D
Fog
✓ (0.5m)
an
f
Heat
Integrated Exercise
(3)
Spelling Corner
the substances must be correct?
Sectional Exercise
10. The set-up on the right consists of several substances put
73
6
Matter as Particles
2.
The photo below shows an ice cream. Part of it is melting.
(a)
Draw the arrangements of the particles of the ice cream in the boxes provided.(2 marks)
..
.
=re
-
Sectional Exercise
melted ice cream
(liquid state)
ice cream
(solid state)
(1m)
(b)
(1m)
When the ice cream melts, it flows and drips along the ice cream cone. Briefly explain
this using the particle theory.
(2 marks)
-
From the particle theory, the particles of the melted ice cream (i) can move around each
other (1m)
. Therefore, the melted ice cream
-
(ii)
does not have fixed shape (1m)
Integrated Exercise
(has fixed shape/does not have fixed shape), and it flows and drips along the ice cream cone.
3.
Simon is dissolving some sugar in a cup of coffee.
Spelling Corner
(a)
Describe the dissolving of the sugar using the particle theory. Assume that there are
coffee and water particles in the cup of coffee.
(3 marks)
-
When the sugar dissolves, the sugar particles (i)
the coffee and water particles (1m)
separate and mix with
. From the particle theory, the sugar particles
-
(b)
(ii)
move randomly (1m)
(iii)
spread out evenly (1m)
all the time and will eventually
en
in the cup.
Simon finds that the sugar dissolves at a higher rate if the coffee is hotter. Suggest ONE
reason to explain this using the particle theory.
(2 marks)
nee
When the temperature is higher, the sugar particles (i)
Therefore, (ii)
drip 向下流
74
move faster (1m)
they can mix with the coffee and water particles at a higher rate (1m)
.
.
Matter as Particles
Jenny will perform an experiment to study whether mass is conserved during dissolving.
She has written a lab manual of this experiment, as shown below.
(a)
Fill in the blanks below.
(3 marks)
Sectional Exercise
Experiment: Is mass conserved during dissolving?
Step 1 Pour water into a beaker until it is two-thirds full. Add two
spoonfuls of salt to a watch glass.
beaker
salt
Integrated Exercise
watch glass
water
Step 2 Measure the total mass of the beaker of water and the watch
-.
electronic balance (1m)
glass of salt using an (i)
Step 3 Transfer all the salt into the water using a spatula.
-
Step 4 Use a (ii)
glass rod (1m)
to stir the water until the
Spelling Corner
4.
6
salt has dissolved completely.
Step 5 Measure the total mass of the beaker of salt solution and the
-.
(iii)
(b)
watch glass (1m)
If the total mass of the salt and water before dissolving is 320 g, what should be the mass
of the salt solution produced after the experiment?
The mass of the salt solution is
lower than) 320 g.
(1 mark)
equal to (1m)
(greater than/equal to/
-
75
6
Matter as Particles
5.
Small gaps are usually left between different road sections, as shown below.
gap
Sectional Exercise
(a)
Using the particle theory, explain what happens to a road in hot weather.
In hot weather, a road is heated up. The (i)
Lin
particles (1m)
- and become (iii)
of the road
--
(ii)
move faster (1m)
As a result, the road (iv)
(b)
(4 marks)
expands (1m)
.
further apart (1m)
.
Suggest ONE reason why small gaps are left between road sections.
(1 mark)
The gaps allow the road to expand in hot weather without damaging the road. (1m)
Integrated Exercise
E
6.
Mrs Chan is using a vacuum compressed storage bag to pack a quilt. She puts the quilt into
the bag and then switches on a vacuum cleaner to remove the air inside the bag. After a
while, the thick quilt is compressed and Mrs Chan puts the cap back to seal the bag.
vacuum compressed
storage bag
to a vacuum
cleaner
Spelling Corner
quilt
cap
(a)
Using the particle theory, briefly explain how the vacuum compressed storage bag
works.
-
When the vacuum pump is switched on, (i)
(4 marks)
is removed from the
air (1m)
hitting the walls of the
bag so the air pressure inside the bag (iii)
. As a result,
bag. There are (ii)
fewer air particles (1m)
decreases (1m)
(iv)
(b)
.
the atmospheric pressure presses against the bag and causes it to compress (1m)
The storage bag cannot work well at the places at high altitudes. Explain why. (2 marks)
The atmospheric pressure is (i)
lower (1m)
Are
at high altitudes and thus
-
(ii)
76
is not large enough to compress the quilt to a small size (1m)
vacuum compressed storage bag 真空壓縮袋
quilt 棉被
seal 封上
.
Matter as Particles
7.
6
The salad dressing below mainly contains oil and vinegar. (Given: the densities of oil and
vinegar are 0.93 g/mL and 1.01 g/mL respectively.)
(a)
Oil and vinegar are not miscible. Suppose that the salad dressing has not been shaken.
Describe the distribution of the contents inside the bottle. Explain briefly.
(2 marks)
S
Sectional Exercise
SHAKE WELL
There are two liquid layers inside the bottle. The top layer is oil and the bottom layer is vinegar. (1m)
If the salad dressing contains 375 mL of oil and 125 mL of vinegar, find the total mass of
the salad dressing.
(2 marks)
⑲
Mass of oil = 375 mL × 0.93 g/mL (1m) = 348.75 g
Mass of vinegar = 125 mL × 1.01 g/mL = 126.25 g
Total mass of the salad dressing = 348.75 g + 126.25 g = 475 g (1m)
Total Score :
/ 50
Spelling Corner
(b)
Integrated Exercise
It is because oil has a lower density than vinegar. (1m)
miscible 可混溶的
77