KUULCHAT
SCIENCE MOCK
OBJECTIVE TEST
1.
The end product of protein digestion is
A.
amino acid.
B.
glucose.
C.
maltose.
D.
poly-peptide.
E.
sucrose.
Answer: A
2.
Which of the following resources does not produce energy?
A.
Coal
B.
Sand
C.
Water
D.
Wind
Answer: B
3.
Photosynthesis is important to living organisms because it produces
A.
glucose and oxygen.
B.
glucose and carbon dioxide.
C.
oxygen and carbon dioxide
D.
water and carbon dioxide.
Answer: A
4.
An example of a vegetable crop is
A.
cocoa.
B.
cotton.
C.
potato.
D.
tomato.
Answer: D
5.
In which of the following situations is work said to be done?
A.
Walking with a load on the head in an upright position
B.
Getting up from a chair
C.
Pushing against a wall which does not move
D.
Sitting still behind a desk
Answer: A
Work done = Force x Distance
For work to be done, force must be applied and distance must be covered.
When at a fixed position, distance covered is 0 hence work done will be 0 even when force is applied to a load at a fixed position.
6.
The part of a living cell which is semi-permeable is
A.
cytoplasm.
B.
nucleus.
C.
protoplasm.
D.
cell membrane.
Answer: D
7.
The main food substance present in the albumen of an egg is
A.
carbohydrate.
B.
fat.
C.
protein.
D.
vitamin.
Answer: C
8.
In which of the following devices is electrical energy transformed into light energy
A.
Electric bell
B.
Fluorescent tube
C.
Lantern
D.
Radio
Answer: B
A fluorescent lamp, or fluorescent tube, is a low-pressure mercury-vapor gas-discharge lamp that uses fluorescence to produce visible light.
9.
Which of the following explains why no work is done when a push is made against a firm wall?
A.
The force acts in the opposite direction
B.
The wall does not move
C.
The force is in the same direction
D.
The material of the wall is strong
E.
The force is in horizontal direction
Answer: B
Work done = Force x Distance
When there is no movement, distance = 0
Work done = Force x 0 = 0 J
10.
Which of the following properties is / are common to both liquids and gases?
A.
Fixed shape
B.
Fixed shape and fixed volume
C.
Fixed size
D.
No definite shape
E.
No definite shape and no definite volume
Answer: D
11.
Which of the following changes does not occur in a girl at the age of puberty?
A.
The breasts develop
B.
The hips widen
C.
Menstruation
D.
The teeth becomes whiter
E.
Hair grows in the pubic area
Answer: D
12.
The force that opposes the motion of an object on another object is called
A.
electrical force.
B.
frictional force.
C.
gravitational force.
D.
magnetic force.
Answer: B
13.
Soup which is not well-heated gets spoilt when kept for sometime because the
A.
salt in the soup is too small.
B.
water in the soup do not all evaporate.
C.
heat in the soup is not enough to kill all bacteria.
D.
water condenses back into the soup.
Answer: C
14.
The component of the soil which is made up of the finest particle is
A.
clay.
B.
humus.
C.
loam.
D.
sand.
Answer: A
15.
Which of the following processes could be used to preserve fish for a long time?
A.
Boiling only
B.
Salting only
C.
Sun drying only
D.
Boiling and sun drying
E.
Salting and sun drying
Answer: E
16.
Which of the following processes is not a physical change
A.
Dissolution
B.
Melting
C.
Boiling
D.
Evaporation
E.
Burning
Answer: E
17.
Plants do not grow well in gravel because the
A.
air spaces are too big to hold water.
B.
air spaces are too small for the roots.
C.
particles cannot absorb air.
D.
particles cannot contain nutrients.
Answer: D
18.
Which of the following living things hide during the sunny days in order to conserve water in its body?
A.
Rat
B.
Lizard
C.
Butterfly
D.
Toad
E.
Bat
Answer: D
19.
One similarity of physical and chemical changes is that both
A.
are easily reversible
B.
result in change of state of matter
C.
produce no change in mass
D.
are accompanied by great heat change
Answer: B
Physical and chemical changes are similar because matter experiences a change in state, Physical
changes are different because matter remains the same substance, just in a different state,
whereas chemical changes change the matter. A chemical change results from a chemical reaction,
while a physical change is when matter changes forms but not chemical identity. Examples of chemical
changes are burning, cooking, rusting, and rotting. Examples of physical changes are boiling,
melting, freezing, and shredding.
20.
When a green leaf is placed in a test tube containing ethanol and heated over a water bath the leaf
A.
becomes soft
B.
changes colour to brown
C.
changes colour to blue-black
D.
is decolorized
Answer: D
21.
Which of the following processes results in the formation of new substances?
A.
Cooling water to form ice
B.
Adding saliva to cooked yam
C.
Dissolving sugar in water
D.
Mixing iron dust and sand
Answer: B
22.
The insect which transmits the plasmodium parasite is called
A.
butterfly.
B.
cockroach.
C.
housefly.
D.
mosquito.
E.
tsetse fly.
Answer: D
23.
The number of oxygen atoms present in three molecules of carbon dioxide is
A.
3.
B.
4.
C.
5.
D.
6.
Answer: D
24.
The study of the soil profile of an area helps the farmer to
A.
control weed growth
B.
determine the soil temperature
C.
determine the types of crop to grow
D.
know the pesticides to use
Answer: C
25.
Which of the following source(s) of energy is/are renewable?
I. Solar
II. Crude oil
III. Wind
A.
I only
B.
I and II only
C.
I and III only
D.
I, II and III
Answer: C
26.
The diagram below shows a lever system used to move a stone. Use it to answer the question below
The distance X is the
A.
effort distance.
B.
load distance.
C.
fulcrum.
D.
lever arm.
Answer: B
Load Distance: is the distance between the pivot (fulcrum) and the load
Effort Distance: Is the distance between the pivot (fulcrum) and the effort
27.
Which of the following statements is true at the boiling point of water?
A.
The mass of the water remains the same.
B.
The temperature increases.
C.
The temperature remains constant.
D.
the volume of the water increases.
Answer: C
28.
Which of the following organisms is likely to increase the oxygen content of the water in a pond?
A.
Fish
B.
Tadpole
C.
Mosquito larva
D.
Water lily
Answer: D
Water lily is a plant. Plants take in carbon dioxide and produces oxygen during the process of photosynthesis.
29.
Which of these objects is a magnetic substance?
A.
Aluminium
B.
Brass
C.
Copper
D.
Iron
Answer: D
30.
Which of the following natural cycles directly involves the sun?
I. Carbon cycle
II. Water cycle
III. Nitrogen cycle
A.
I, II and III
B.
I and II only
C.
II and III only
D.
I only
Answer: B
31.
A substance that could be used in large scale treatment of domestic water is
A.
Nitrogen.
B.
Hydrogen sulphide.
C.
Carbon dioxide.
D.
Chlorine.
Answer: D
32.
The main reason for staking tomato is to ensure
A.
bigger fruit development.
B.
air circulation on the farm.
C.
upright growth of the plant.
D.
that fruits do not get rotten.
Answer: D
Staking tomatoes provides support to help keep plants off the ground while assisting in their upward growth habit.
Because many diseases and insects start at the ground level, using a structured system to keep them away from ground contact is prudent.
Staking can also be used to prevent the fruit from beginning to rot as it sits on the ground as the stalk grows overtime.
33.
Sleeping sickness is spread by
A.
blackfly
B.
firefly
C.
Mosquito
D.
Housefly
E.
Tsetse fly
Answer: E
34.
A mixture of sugar and water could be separated by
A.
decantation.
B.
evaporation.
C.
filtration.
D.
sublimation.
Answer: B
35.
When a solid-liquid mixture is filtered, the liquid that separates out into the container is called
A.
filtrate.
B.
residue.
C.
sediment.
D.
solution.
Answer: A
Filtration set up
36.
Which of the following organisms is prokaryotic?
A.
Bacteria
B.
Earthworm
C.
Fungus
D.
Plant
Answer: A
A prokaryotic organism is a single-celled life form that lacks a nucleus and other membrane-bound organelles. Prokaryotes are typically found in the domains Bacteria and Archaea. They are characterized by their relatively simple structure and the absence of internal membranes that define eukaryotic cells.
37.
A free movement of the bowels is aided by
A.
sleeping at least 6 hours a day.
B.
washing one's body at least twice a day.
C.
eating fatty foods.
D.
eating foods containing fibre.
Answer: D
38.
When an atom loses an electron, the ion formed is called
A.
an anion.
B.
a cation.
C.
a molecule.
D.
a compound.
Answer: B
Ion: is a charged atom or a group of atoms which possesses an electric charge.
Cation: The ion formed when an atom loses electron(s) is known as cation e.g. Na+, Mg2+
Anion: The ion formed when an atom gains electron(s) is known as anion e.g Cl-, O2-
39.
The force that binds molecules of the same substances together is called
A.
adhesion.
B.
cohesion.
C.
capillary action.
D.
surface tension.
Answer: B
Difference between adhesive and cohesive force
Cohesive force is the force that attracts molecules of the same substance while Adhesive force is the force that binds molecules of different substances together.
Why water wets glass
Water wets glass and spreads out on it because the adhesive forces between the liquid and the glass are stronger than the cohesive forces within the water.
40.
A substance of mass 10 kg has a density of 2.0 kgm-3. Calculate its volume.
A.
0.2 m3
B.
5.0 m3
C.
10.0 m3
D.
20.0 m3
Answer: B
Density =
Density x Volume = Mass
Dividing both sides by Density
Volume =
Volume =
Volume = 5 m3
THEORY QUESTIONS
1.
a)
In an experiment to demonstrate a property of light, three cardboards, A, B, and C with holes in their centres are arranged in a straight line between a lighted bulb and an observer as shown in the illustration below.
Study the illustration carefully and use it to answer the question that follow:
i)
What would the observer see from the position shown?
ii)
What would the observer see when cardboard B is slightly displaced from the line?
iii)
Explain the observation made in (a) (ii) above.
iv)
What would be observed when the cardboard B is brought back to its original position?
v)
What property of light is being demonstrated in this experiment?
vi)
Mention
α)
two natural occurrences that could be explained by the property of light demonstrated.
β)
one device that works on the property of light demonstrated.
b)
The diagrams below are illustrations of hazards symbols found in everyday life.
Study them carefully and use them to answer the questions that follow:
i)
What does each symbol A, B, C and D represent?
ii)
Name one substance each that is associated with each of the symbols A, B and C.
iii)
Name one place where the symbols D can be found.
iv)
State two advantages of hazard symbols.
c)
The diagrams below are illustrations of the different types of teeth in humans.
Study them carefully and use them to answer the questions that follow:
i)
Identify each type of teeth labelled A, B and C.
ii)
Describe the shape of each of the teeth labeled A, B and C.
iii)
State one function of each of the teeth labeled A, B and C.
iv)
Name the parts of the teeth labeled I and II.
d)
The diagrams below are illustrations of some farm tools.
Study them carefully and use them to answer the questions that follow:
i)
Identify each of the following labeled A, B, C, D and E.
ii)
Mention one use of each of the tools labeled A, B, C, D and E.
a)
i)
Light/lighted bulb/light ray(s)
ii)
No light would be seen/part of the cardboard B would be seen.
iii)
Light travels in a straight line and because cardboard B is shifted out of the straight line, the light is not seen again.
iv)
The lighted bulb/light/light rays(s).
v)
Linear/rectilinear propagation of light/light travels in a straight line.
vi)
α)
Natural occurrences that could be explained by the property of light demonstrated
1. Eclipse
2. Shadow
β)
Devices that works on the property of light demonstrated
1. Pinhole camera
2. Periscope
3. Touch light
4. Hunter's lamp
5. Parabolic mirror
6. Car lamps
7. Optical fibre
8. Laser
9. Binoculars
b)
i)
A → Highly inflamable/flammable/catches fire easily
B → Harmful/irritant
C → toxic/poison/poisonous
D → Danger
ii)
Highly inflammable substances (A)
1. Petrol
2. Kerosene
3. Gas/Liquefied Petroleum Gas (LPG)
4. Sodium
5. Ethanol
6. Thinner
7. Turpentine
8. Carbon disulphide
Harmful/irritant substances (B)
1. Sodium hydroxide
2. Mineral acids/Phenol/H2SO4/HNO3
3. Aluminum sulphate
4. Calcium Hydroxide
Toxic/poisonous substances (C)
1. Cyanide
2. DDT
3. Mercury
4. Lead compounds
iii)
Places where the symbols D(Danger) can be found
1. Highways/roads
2. High voltage equipment
3. Laboratories
4. Construction sites
iv)
Advantages of hazard symbols
1. They warn us of danager so that we do not harm ourselves
2. They prevent accidents or damage of properties
c)
i)
A → Incisor B → Premolar/molar/cheek tooth C → Canine
ii)
Shape of A(Incisor)
Is chisel shaped
Shape of B(Premolar)
Has flat and broad surface with cusps/ridges/projections
Shape of C(Canine)
(Bluntly) pointed/conical
iii)
Function of A(Incisor)
For cuttin/biting
Function of B(Premolar)
For grinding/chewing/crushing
Function of C(Canine)
For tearing
iv)
I → Enamel/Crown
II → Root
d)
i)
A → Garden fork/digging fork/foot fork
B → Spade
C → Hand trowel
D → Hand fork
E → Watering can
ii)
Uses of A(Garden fork)
1. Turning/loosening soil
2. Stirring soil
Uses of B(Spade)
1. Turning soil
2. Collection of soil
3. Levelling of soil surface
4. Mixing of animal feeds
Uses of C(Hand trowel)
1. Transplanting seedlings
2. Earthing up vegetable crops
3. Heaping soil around vegetable crops
4. Spreading manure
Uses of D(Hand fork)
Stirring/Loosening soil in nursery beds/vegetable beds
Uses of E(Watering can)
Watering
2.
(a)
For each of the following diseases, name the causative organism and one method of prevention.
(i)
Cholera
(ii)
Bilharzia
(iii)
Malaria
(iv)
Tuberculosis
(b)
Show how you would separate each of the following mixtures:
(i)
Common salt and sand
(ii)
Muddy water
(c)
Explain why the planet and their moons move around the sun but they do not clash.
(d)
Give two uses of the sun's energy in everyday life.
(a)
| Disease | Causative Organism | Prevention |
| Cholera | Vibrio Cholerae |
1. Drinking of pure/boiled water
|
| Bilharzia | Schistosoma |
1. Keeping the surroundings clean
|
| Malaria | Plasmodium |
1. Using mosquito nets
|
| Tuberculosis | Tuberculo Bacillus |
1. Avoiding over crowding
|
(b)
(i)
Separation of common salt and sand
1. Dissolve the common salt by adding water to the mixture in a beaker
2. Stir the mixture
3. Filter the sand from the salt solution using filter paper in a funnel
4. Using a Bunsen burner, heat the salt solution to retrieve the salt in an evaporating dish
(ii)
Separation of muddy water
1. Fold a filter paper into a funnel
2. Pour the muddy water into the funnel and filter
3. The water is then collected by a beaker and sand is left on the filter paper
(c)
Why the planet and their moons move around the sun but they do not clash
The gravitational force of attraction of the sun on the planets and their moons provides the centripetal force that keeps the planets and their moons moving in their respective orbits around the sun without clashing
(d)
Uses of the sun's energy in everyday life
1. It provides energy for photosynthesis in plants
2. It generates energy for solar panels
3. It is a source of light
4. It helps the skin produce vitamin D as it shines on the skin
5. It is used for drying clothes
3.
a)
i)
What is an embryo?
ii)
Where does an embryo develop in the female mammal?
iii)
Describe briefly how a developing embryo breathes in oxygen.
b)
Name three plant nutrients.
c)
i)
What is an electrical insulator?
ii)
Explain how a comb rubbed vigorously on dry hair attracts small pieces of paper.
d)
i)
List the chemical substances that are used in the preparation of ammonia gas in the laboratory.
ii)
Write down balanced chemical equation for the reaction.
a)
i)
Embryo is the first stage of the development of a zygote (eight weeks after conception in mammals).
ii)
In the womb or uterus of the female mammal
iii)
How a developing embryo breathes in oxygen
Oxygen from the mother's blood diffuses through the placenta into the embryo.
b)
Plant nutrients
1. Nitrogen
2. Calcium
3. Zinc
4. Iron
5. Magnesium
6. Phosphorus
7. Potassium
8. Sulphur
c)
i)
An electrical insulator is a substance/material which does not conduct electrcity
OR
An electrical insulator is a substance/material which does not allow electricity to pass through it
ii)
How a comb rubbed vigorously on dry hair attracts small pieces of paper
1. Comb rubbed in hair causes the comb to be charged
2. When the comb is brought near pieces of paper it induces an oppsite charge on the pieces of paper
3. The pieces of paper are attracted to the comb because of the opposite charges
d)
i)
Chemical substances that are used in the preparation of ammonia gas
1. Ammonium chloride
2. Calcium hydoxide/Calcium oxide
ii)
2NH4Cl + Ca(OH)2 → CaCl2 + 2H2O + 2NH3(g)
OR
2NH4Cl + CaO → CaCl2 + H2O + 2NH3(g)
4.
(a)
Define the following terms:
(i)
erosion
(ii)
reproduction
(iii)
parasite
(iv)
excretion
(b)
Give one example each of erosion and parasite.
(c)
Draw and label a diagram of the female reproductive organ in a human being.
(d)
(i)
Define the term work.
(ii)
An amount of 300.0 J of work is done when a force moves through a distance of 10.0 m in the direction of the force. Calculate the value of the force.
(e)
Write down the names of the following compounds:
(i)
NH4Cl
(ii)
HCl
(iii)
CuSO4
(iv)
FeCl3
(f)
Explain how sulphur can be obtained from a mixture of powdered sulphur and iron filings.
(a)
(i)
Erosion is the washing away/the removal and carrying away of the top soil by running water, rain or wind.
(ii)
Reproduction is the process by which living organisms give rise to/produce young ones of their own kind.
(iii)
Parasite is any organism/living thing that lives in or on another organism/living thing called the host for its food and by so doing causes harm to the host.
(iv)
Excretion is the process of removing metabolic waste/substances from the body of a living organism.
(b)
Examples of erosion
1. Rill erosion
2. Gully erosion
3. Splash erosion
4. Sheet erosion
Examples of parasite
1. Tapeworm
2. Plasmodium
3. Dodder
4. Tick
5. Body louse
6. Mistletoe
7. Capsids
(c)
A labelled diagram of the female reproductive organ in a human being
(d)
(i)
Work is said to be done when the point of application of a force moves an object through a distance in the direction of the force.
OR
Work is said to be done when a force moves a body through a distance in the direction of the force.
OR
Work is the product of force and the distance moved in the direction of the force.
OR
Work = Force x distance moved in the direction of the force
(ii)
Work = Force x Distance moved in the direction of the force
Work = 300 J
Distance = 10 m
300 J = Force x 10 m
Divide both sides by 10 m
Force = = 30 N
(e)
(i)
NH4Cl → Ammonium chloride
(ii)
HCl → Hydrochloric acid/Hydrogen chloride
(iii)
CuSO4 → Copper (II) sulphate/Copper (II) tetraoxosulphate (VI)
(iv)
FeCl3 → Iron (III) chloride
(f)
How sulphur can be obtained from a mixture of powdered sulphur and iron filings
1. Spread the mixture on a sheet of paper
2. Use a magnet to pick the iron filings from the mixture
3. Sulphur is left on the sheet of paper
5.
(a)
Figure 1(a) is an illustration of a natural cycle showing unnamed stages and processes labelled A, B, C and D with processes labelled P, Q, S and T. Study the figure carefully and answer the questions that follow.
(i)
Name each of the stages labelled A, B, C and D.
(ii)
Name each of the processes labelled P, S and T.
(iii)
State three activities of humans that could disrupt the cycle.
[10 marks]
(b)
Figure 1(b) is an illustration of two types of farming systems practised in Ghana labelled K and L.
System K represents four farmlands labelled A, B, C and D and the arrows indicate movement of the farmer over a period of time as shown.
System L, represents a farmland divided into four plots 1, 2, 3 and 4 and the arrows indicate the movement of the crops cultivated over the period.
Study the figure carefully and answer the questions that follow.
(i)
Name each of the farming systems labelled K and L
(ii)
Give the reason for each of the names given in (i).
(iii)
State two ways in which the farming system K is of importance to the farmer.
(iv)
Give three reasons why the farming system K is not being encouraged in recent times.
(v)
Name one type of crop that could be included in the farmland L to improve the fertility of the soil.
[10 marks]
(c)
Figure 1(c) is an illustration of a mason pulling a slab by means of a rope up an inclined plane. The labels I, II and III represent forces acting on the slab.
Study the figure carefully and answer the questions that follow.
(i)
Give three examples of the use of inclined planes in everyday life.
(ii)
Given that I is 400 N and moves a distance of 10 m whiles II is 100 N and moves a distance of 5 m, calculate the
(α)
work output;
(β)
work input;
(γ)
efficiency.
[10 marks]
(d)
Figure 1(d) is an illustration of experimental set-ups A and B used to demonstrate a scientific principle.
Study the figure carefully and answer the questions that follow.
(i)
Name the scientific principle being demonstrated in both A and B.
(ii)
Describe briefly the functions of each of the parts labelled II and VI.
(iii)
Name any two types of materials that could be present in each of the set-ups labelled:
(α)
III;
(β)
VII.
(iv)
Give the reason why the direction of water flow in A must not be reversed.
[10 marks]
(a)
(i)
A → Plants
B → Carbon dioxide in the atmosphere
C → Animals
D → Dead/decaying organisms/organic matter
4 @ 1 mark each = 4 marks
(ii)
P → Photosynthesis
S → Decay/decomposition
T → Combustion/burning
3 @ 1 mark each = 3 marks
(iii)
Activities of humans that could disrupt the cycle
1. Raising of livestock
2. Growing of crops
3. Burning of wood
4. Burning of fossil fuels/coal/industrial pollution
5. Reducing amount of forest cover/deforestation
Any 3 x 1 = 3 marks
(b)
(i)
K → Land rotation
L → Crop rotation
2 @ 1 mark each = 2 marks
(ii)
Reason for K
The farmer moves from one farmland to another
Reason for L
The farmer moves/rotates the crops from one plot to another
2 @ 1 mark each = 2 marks
(iii)
Ways in which the farming system K is of importance to the farmer
1. The soil regains its fertility/prevents soil exhaustion
2. There is control in the build-up pests and diseases
3. It helps to maintain good yield
4. Saves money
Any 2 x 1 = 2 marks
(iv)
Reasons why the farming system K is not being encouraged in recent times
1. Time, energy and money is wasted in clearing new land each time land is abandoned.
2. System does not encourage large scale farming
3. There is rampant deforestation
4. Cultivated lands are generally small and scattered
5. Land is getting scarce/a growing population
Any 3 x 1 = 3 marks
(v)
Leguminous crops
1 mark
(c)
(i)
Examples of the use of inclined planes in everyday life
1. Stair case
2. Ladder
3. Plank of wood at an angle
4. Hill
5. Ramps
6. Screws
Any 3 x 1 = 3 marks
(ii)
(α)
Work output = Load x Load distance (1 mark)
Work output = 100 x 5
Work output = 500 J (1 mark)
(β)
Work input = Effort x Effort distance (1 mark)
Work input = 400 x 10
Work input = 4000 J (1 mark)
(γ)
Efficiency = x 100% (1 mark)
Efficiency = x 100% (1 mark)
Efficiency = 12.5% (1 mark)
Notes:
1. The zeros (0) in 500 and 4000 cancel each other
2. The zeros (0) in 40 and 100 cancel each other
3. 2 divides 4, 2 times and 10, 5 times
4. = = 12.5
(d)
(i)
Separation of mixtures
1 mark
(ii)
II
Cools the vaporized components of the mixture (1 mark) back to liquid (1 mark)
VI
Bar magnet attracts the magnetic material of the components of a mixture (1 mark) in order to separate it from the non-magnetic component (1 mark)
(iii)
(α)
III
1. Alcohol/ethanol and water
2. Kerosene and diesel oil
Any 1 x 2 marks = 2 marks
(β)
VII
Iron filings and powdered Sulphur
2 marks
(iv)
To ensure complete condensation of the vapour
1 mark
6.
(a)
(i)
Give the names of organisms which cause the following diseases:
Sleeping sickness, Cholera, Malaria, Bilharzia
(ii)
Which part of the following crops does a farmer usually grow?
Banana, cocoyam, tomato, ginger, yam, cassava
(b)
Name the organs used by the following organisms for respiration:
(i)
Tilapia
(ii)
Toad
(c)
(i)
What happens to the temperature of water that is boiling in an open container?
(ii)
Give two characteristics of a liquid.
(iii)
Name the three processes by which heat is transmitted.
(iv)
State two applications of the expansion of solids in everyday life.
(d)
Explain the following terms:
(i)
Physical change
(ii)
Chemical change
(e)
State whether each of the following is a physical or a chemical change
(i)
rusting of iron
(ii)
freezing of water
(iii)
burning of wood
(iv)
fermentation
(v)
grinding of chalk
(vi)
dissolving sugar in water
(f)
Name the compound formed when theh following elements combine:
(i)
Iron and sulphur
(ii)
Zinc and oxygen
(iii)
Sodium and chlorine
(iv)
Calcium and chlorine
(a)
(i)
| Disease | Organism |
| Sleeping sickness | Trypanosome/Trypanosoma |
| Cholera | Vibrio cholerae |
| Malaria | Plasmodium |
| Biharzia | Blood fluke/Schistosoma/Schistosome |
(ii)
| Crop | Part grown |
| Banana | Sucker |
| Cocoyam | Corm/underground stem |
| Tomato | Seed |
| Ginger | Rhizome/underground stem |
| Yam | Tuber/stem tuber/underground stem |
| Cassava | Stem cutting/cassava sticks |
(b)
Organs for respiration:
(i)
Tilapia → Gills
(ii)
Toad → Lungs or skin or mouth
(c)
(i)
The temperature remains the same/unchanged/constant
(ii)
Characteristics of a liquid
1. Has no definite shape/takes the shape of container
2. Has volume/occupies space
3. Molecules/particles are not in fixed positions
4. Molecules move about randomly
5. Not compressible
(iii)
1. Conduction
2. Convection
3. Radiation
(iv)
Applications of the expansion of solids in everyday life
1. Railway line gaps
2. Rollers in metal bridges
3. Thermostat
4. Concrete slabs
5. Riveting
6. Fixing wheels
(d)
(i)
Physical change is a change in which no new substance is formed
OR
Physical change is a change in which no new substances are formed
OR
Physical change is a change in which substances retain their individual properties.
(ii)
Chemical change is a change in which a new substance is formed
OR
Chemical change is a change in which new substances are formed
OR
Chemical change is a change in which new substances formed have entirely different properties from their constituents.
(e)
| Physical change | Chemical change |
| Freezing of water | Rusting of iron |
| Grinding of chalk | Burning of wood |
| Dissolving sugar in water | Fermentation |
(f)
(i)
Iron and sulphur → Iron sulphide/Iron (II) sulphide/Iron (III) sulphide
(ii)
Zinc and oxygen → Zinc oxide
(iii)
Sodium and chlorine → Sodium chloride
(iv)
Calcium and chlorine → Calcium chloride