KUULCHAT
SCIENCE MOCK
OBJECTIVE TEST
1.
An atom of carbon is represented as 612 C. How many neutrons are in the nucleus of the carbon atom?
A.
2
B.
4
C.
6
D.
12
Answer: C
The superscript represents the mass number which is made up of neutrons and protons
The value of the superscript is 12.
Number of protons + Number of neutrons = 12
The subscript represents the atomic number which is the number of electrons in a neutral atom. In a neutral atom, the number of electrons is equal to the number of protons.
Atomic number = 6
Atomic number = Number of electrons
Number of electrons = Number of protons
Number of electrons = 6
Number of protons = 6
Protons + Neutrons = 12
6 + Neutrons = 12
Neutrons = 12 - 6
Neutrons = 6
2.
A book is at rest on a table. The net force acting on the book could be described as one that
A.
is balanced.
B.
is unbalanced.
C.
is due to friction.
D.
obeys Newton's second law.
Answer: A
The forces (net forces) on the book are balanced because the gravity pulling down on the book is equal to the upward force applied by the table.
3.
Energy stored in food is referred to as
A.
chemical energy.
B.
heat energy.
C.
solar energy.
D.
kinetic energy.
Answer: A
4.
Which of the following diseases is transmitted by close contact with an infected person?
A.
AIDS
B.
Bilharzia
C.
Elephantiasis
D.
Measles
E.
Polio
Answer: D
5.
Which of the following statements about a plant cell is correct? It
A.
does not have a nucleus.
B.
contains large vacuoles.
C.
is surrounded by the cell membrane only.
D.
does not have a definite shape.
Answer: B
6.
Which of the following life activities are common to both plants and animals?
I. Feeding
II. Locomotion
III. Respiration
A.
I and II only
B.
I and III only
C.
II and III only
D.
I, II and III
Answer: B
7.
Which of the following particles constitute matter?
I. Atoms
II. Molecules
III. Ions
A.
I only
B.
II only
C.
II and III only
D.
I, II and III
Answer: D
8.
One best way of making water safe for drinking is by
A.
adding washing soda.
B.
filtering.
C.
adding common salt.
D.
boiling.
Answer: D
9.
Steel is an alloy of
A.
Iron and Carbon
B.
Zinc and Copper
C.
Tin and Copper
D.
Iron and Zinc
E.
Carbon and Zinc
Answer: A
10.
The energy transformation that takes place in a solar cell is
A.
light to chemical.
B.
light to electrical.
C.
electrical to heat.
D.
electrical to light.
Answer: B
Light energy is converted into electrical energy.
11.
A stone displaced 20 cm3 of water when immersed in the water. If the mass of the stone is 40 g. find the density of the stone
A.
60 g cm-3
B.
40 g cm-3
C.
2 g cm-3
D.
0.5 g cm-3
Answer: C
Density
Density =
Mass = 40 g
Volume = 20 cm3
Density =
Density = 2 g cm-3
12.
The weight of an object is the
A.
force with which the sun pulls it
B.
force with which the moon pulls it
C.
force of the object when gravity is not acting on it
D.
force with which gravity acts on it
E.
mass of the object
Answer: D
13.
Which of the following insect(s) show(s) the egg, nymph and adult stages in its life cycle?
I. Grasshopper
II. Housefly
III. Mosquito
A.
I only
B.
I and II only
C.
II and III only
D.
I, II and III
Answer: A
Grasshopper life cycle
Grasshoppers are hemimetabolous insects. Hence, their life cycle consists of three stages – the egg, the nymph, and the adult.
Housefly life cycle
The life cycle of housefly comprises four stages namely, egg, larva, pupa and adult.
Mosquito life cycle
Life cycle of mosquito consists of four stages namely, egg, larval, pupal, and adult.
14.
The SI unit that is derived is
A.
kg.
B.
k.
C.
Pa.
D.
s.
Answer: C
Derived unit is a unit obtained from the base/fundamental unit. Pa is a unit for pressure which is obtained from kg⋅m−1⋅s−2
15.
Kerosene and petrol are obtained from crude oil by
A.
condensation of the crude oil
B.
decantation of the crude oil
C.
distillation of the crude oil
D.
evaporation of the crude oil
E.
filtration of the crude oil
Answer: C
16.
The force, which opposes the motion of one body on another body is called
A.
adhesion.
B.
cohesion.
C.
friction.
D.
tension.
Answer: C
17.
An example of a communicable disease is
A.
asthma.
B.
diabetes.
C.
hepatitis.
D.
hypertension.
Answer: C
A communicable disease, also known as an infectious disease, is an illness that can be spread from one person to another, or from an animal to a person. These diseases are caused by pathogens like bacteria, viruses, fungi, or parasites. They can be transmitted through various means, including direct contact, contaminated surfaces, bodily fluids, or airborne particles.
Hepatitis
Hepatitis refers to inflammation of the liver, and can be caused by various factors including viral infections, alcohol abuse, toxins, certain medications, and autoimmune conditions. Viral hepatitis, caused by viruses like hepatitis A, B, C, D, and E, is a major concern, with hepatitis B and C being the most common causes of chronic liver disease, cirrhosis, and liver cancer.
18.
The type of cloud found closest to the earth's surface is
A.
cirrus.
B.
cumulus.
C.
stratus.
D.
stratocumulus
Answer: C
19.
The process by which gas changes to liquid is known as
A.
melting.
B.
evaporation.
C.
condensation.
D.
boiling.
Answer: C
20.
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
21.
Which of the following arrangements is the correct order of increasing complexity of the structure?
A.
Cells → systems → tissues → organs
B.
Cells → tissues → systems → organs
C.
Cells → organs → tissues → systems
D.
Cells → systems → organs → tissues
E.
Cells → tissues → organs → systems
Answer: E
22.
An example of the process of osmosis is
A.
Selective reabsorption
B.
Absorption of digested food
C.
The spread of petrol scent
D.
Gaseous exchange in living things
Answer: A
23.
Which of the following parasites lives in the blood of humans?
A.
Louse
B.
Plasmodium
C.
Tapeworm
D.
Tick
Answer: B
Plasmodium is the parasite that cause malaria in humans.
24.
The amount of water vapour in the atmosphere is called
A.
fog.
B.
humidity.
C.
rain.
D.
temperature.
Answer: B
25.
Which of the following statements accurately explains the positions of calcium and magnesium in the periodic table? They all have the same
A.
proton number.
B.
valence electrons.
C.
number of shells.
D.
atomic structure.
Answer: B
Valence electrons are the electrons located in the outermost electron shell of an atom, and they are crucial for determining an atom's chemical behavior. These electrons participate in chemical bonding and influence an element's reactivity and stability.
Calcium has 20 electrons and the electronic configuration is 2,8,8,2
Magnesium has 12 electrons and the electronic configuration is 2,8,2
Has you can see both atoms has 2 electrons in their outermost (last) shell. Thus 2 valence electrons.
26.
Which of the following crops improves soil fertility when cultivated continuously on the same piece of land?
A.
Carrot
B.
Cocoa
C.
Cassava
D.
Maize
E.
Peas
Answer: E
Pea is a leguminous crop. Legumes improve soil fertility through the symbiotic association with microorganisms, such as rhizobia, which fix the atmospheric nitrogen and make nitrogen available to the host and other crops by a process known as biological nitrogen fixation (BNF).
27.
Chlorine gas is an example of
A.
an atom.
B.
an element.
C.
a compound.
D.
a molecule.
Answer: D
28.
The nearest planet to the sun in the solar system is
A.
Earth
B.
Mars
C.
Mercury
D.
Venus
Answer: C
Mercury is the smallest planet in our solar system and nearest to the Sun, Mercury is only slightly larger than Earth's Moon.
29.
A stick placed in water appears to be bent because light travelling from the water to the air is
A.
dispersed.
B.
displaced.
C.
refracted.
D.
reflected.
Answer: C
Refraction is the bending of light (it also happens with sound, water and other waves) as it passes from one transparent substance into another. This bending by refraction makes it possible for us to have lenses, magnifying glasses, prisms and rainbows. Even our eyes depend upon this bending of light.
30.
The element used in the manufacturing of electronic components is
A.
sodium.
B.
fluorine.
C.
silicon.
D.
neon.
Answer: C
31.
Which of the following insect pests of crops has piercing and sucking mouthparts?
A.
Aphids
B.
Grasshoppers
C.
Stemborers
D.
Termites
Answer: A
32.
Which of the following is the percentage composition of oxygen in the air?
A.
0.03
B.
1
C.
21
D.
78
E.
98
Answer: C
33.
One disease that affects the nervous system of humans is
A.
filariasis.
B.
measles.
C.
poliomyelitis.
D.
typhoid
Answer: C
Poliomyelitis (Polio) is a highly infectious disease caused by a virus. It invades the nervous system and can cause total paralysis in a matter of hours.
34.
Purple colouration of leaves of plant is a major symptom of deficiency in
A.
Calcium
B.
Nitrogen
C.
Potassium
D.
Phosphorus
Answer: D
35.
The darkest part of a shadow formed during an eclipse is called
A.
Lunar eclipse
B.
Annular eclipse
C.
Penumbra
D.
Umbra
E.
Solar eclipse
Answer: D
36.
Which of the following examples of fertilizers improves soil texture?
A.
Compost
B.
N.P.K.
C.
Sulphate of ammonia
D.
Urea
Answer: A
37.
Tuberculosis is spread
A.
through eating of contaminated food.
B.
when an infected person coughs openly into the air.
C.
through shaking of hands of infected persons.
D.
through sharing of contaminated syringes.
Answer: B
38.
What is the chemical symbol for silver?
A.
Ag
B.
Au
C.
Si
D.
S
Answer: A
39.
Chinchilla is a breed of
A.
goats.
B.
pigs.
C.
rabbits.
D.
sheep.
Answer: C
40.
Which of the following substances is a compound?
A.
Oxygen
B.
Magnesium
C.
Water
D.
Sodium
Answer: C
A compound consists of two or more different elements chemically combined in a fixed ratio. Oxygen, magnesium and sodium are all elements but water is a compound made up of hydrogen and oxygen (H2O)
THEORY QUESTIONS
1.
(a)
Distinguish between the following terms:
(i)
Physical change and chemical change
(ii)
Solution and suspension
(b)
Classify the following as either a physical or chemical change
(i)
Common salt in water
(ii)
Burning of charcoal
(iii)
Melting of ice
(iv)
Hydrochloric acid in sodium hydroxide solution
(c)
(i)
What is a parasite?
(ii)
Give two examples of parasites and their hosts.
(d)
Give the chemical symbols of the following elements
(i)
Oxygen
(ii)
Chlorine
(iii)
Aluminium
(iv)
Calcium
(e)
(i)
Explain the term self-pollination
(ii)
Name four agents of pollination
(iii)
State the function of the brightly coloured petals in insect pollination
(a)
(i)
Differences between a physical change and a chemical change
| Physical Change | Chemical Change |
| No new substance is formed | New substance is formed |
| It is easily reversible | It is irreversible |
| It is not accompanied by great heat change | It is accompanied by great heat change |
| There is no change in mass | There is change in mass |
| Individual components retain their properties | Individual components lose their properties |
(ii)
Difference between solution and suspension
A solution is a uniform/homogeneous mixture of a solute and a solvent where the solute completely disappear from sight in the solvent (liquid) whiles a suspension is a mixture of particles of an insoluble substance and a liquid whereby the particles of the substance float in the liquid. The small particles settle at the bottom of the container when it is left undisturbed.
(b)
(i)
Common salt in water → physical change
(ii)
Burning of charcoal → chemical change
(iii)
Melting of ice → physical change
(iv)
Hydrochloric acid in sodium hydroxide solution → chemical change
(c)
(i)
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.
(ii)
Examples of parasites and their hosts
| Parasite | Host |
| Lice | Man |
| Tick | Dog |
| Plasmodium | Man |
| Mistletoe | Cocoa/cola |
| Dodder | Milk bush/cashew plant |
| Capsids | Cocoa plant |
| Tapeworm | Cow/pig/man |
(d)
Chemical symbols
(i)
Oxygen → O
(ii)
Chlorine → Cl
(iii)
Aluminium → Al
(iv)
Calcium → Ca
(e)
(i)
Self-pollination is the transfer of pollen grains from the anther of a flower to the stigma of the same flower or to the stigma of another flower of the same plant.
(ii)
Agents of pollination
1. Insects
2. Water/Rain
3. Animal/Man/Birds/Bats
4. Wind
(iii)
Function of the brightly coloured petals in insect pollination
They produce nectar which attracts insects to the plant.
2.
(a)
A sample of garden soil is put in a cylinder containing water. It is shaken and allowed to settle.
Draw and label the layers formed.
(b)
(i)
Name four types of forces.
(ii)
A boy used a catapult to pluck a mango from a tree. State two forces involved in this activity.
(iii)
Where are the forces in (b) (ii) applied?
(c)
Describe an experiment to show that there is change in heat energy when a new substance is formed.
(a)
(b)
(i)
Types of forces
1. Force of gravity
2. Weight
3. Magnetic force
4. Electrostatic force
5. Frictional force
6. Centripetal force
7. Viscous force
8. Tensional/Elastic force
9. Adhesion
10. Cohesion
11. Centrifugal force
(ii)
1. Tensional/Elastic force
2. Force of gravity
3. Frictional force
(iii)
1. Tension/elastic force in the rubber band of the catapult pushed the stone
2. Force of gravity brought down the mango
3. Frictional force acts between the stone and the mango/between the leather of the catapult and the stone/between the palm and the stick of the catapult
(c)
Experiment to show that there is change in heat energy when a new substance is formed
1. Take two solutions/substances such as lead nitrate/lead (II) trioxonitrate (V) and dilute hydrochloric acid
2. Measure the temperature of the separate solutions and record
3. Pour the acid into the nitrate
4. Measure the temperature as you stir gently
5. It will be observed that a new substance is formed with a change in temperature
6. It can therefore be concluded that there is a change in heat energy when a new substance is formed
3.
(a)
(i)
Describe briefly what happens to a morsel of kenkey in the mouth during eating.
(ii)
List in order, the parts of the digestive system of humans.
(b)
A mixture of iron filings and sulphur is heated in a test tube
(i)
Give the name of the compound formed
(ii)
Write the chemical equation of the reaction which took place.
(iii)
State two methods of preventing iron from rusting.
(c)
(i)
A boy pulled a load through a distance of 5 m. If he exerts a force of 15 N in the direction of the force, calculate the work done
(ii)
Convert the following weights expressed in kilogram force (kgf) to newton (N)
α)
0.75 kgf
β)
1.33 kgf
[1 kgf = 10 N]
(a)
(i)
Digestion of a morsel of kenkey in the mouth
1. The morsel of kenkey is chewed, mixed with saliva so that it can be easily swallowed
2. The ptyalin/enzyme in saliva acts on the starch present in the kenkey and changes it to maltose
(ii)
The parts of the digestive system of humans listed in order
Mouth → oesophagus/gullet → stomach → duodenum → ileum → colon → rectum → anus
(b)
Reaction between iron filings and sulphur
(i)
The name of the compound formed
Iron sulphide/Iron (II) sulphide
(ii)
The chemical equation of the reaction
Fe + S → FeS
(iii)
Methods of preventing iron from rusting
1. Painting
2. Galvanization
3. Greasing/oiling/lubricating
4. Tin plating
5. Alloying
6. Plastic coating
7. Electroplating
8. Sacrificial protection/cathodic protection
(c)
(i)
Work done = Force x Distance
Force = 15 N
Distance = 5 m
Work done = 15 N x 5 m = 75 J
(ii)
α)
If 1 kgf = 10 N
0.75 kgf = = 10 N x 0.75 = 7.5 N
β)
If 1 kgf = 10 N
1.33 kgf = = 10 N x 1.33 = 13.3 N
4.
(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
5.
a)
State three ways in which crop rotation is important in crop production.
b)
State three properties of the image formed by a plane mirror.
c)
i)
What is photosynthesis?
ii)
Explain briefly why a digestive system is necessary in humans.
d)
Give the systematic name of the following compounds:
i)
α)
MgCl2;
β)
FeS.
ii)
What is an element?
iii)
What is the name given to a solid mixture?
a)
Importance of crop rotation
1. Increases soil fertility/Adds nitrogen to soil
2. Enhances soil structure
3. Prevents soil erosion
4. Improves soil nutrients and nutrient uptake regulation
5. Controls the spread of pests and diseases
6. Controls weed easily
7. There is effective use of the land
8. Harvest of different types of crops on the same piece of land
b)
Properties of image formed by a plane mirror
1. It is virtual
2. It is upright
3. Same size/shape as the object
4. The distance of the object from the plane mirror is the same as the distance of the image from the plane mirror
5. It is laterally inverted
c)
i)
Photosynthesis is the process by which green plant produces their own food/carbohydrate/glucose/starch using carbon dioxide and water with the presence of sunlight and chlorophyll.
ii)
Importance of digestive system
It breaks down food so that it can be used by the body for energy/cell growth or repair
d)
i)
Systematic Names
α)
MgCl2 → Magnesium Chloride
β)
FeS → Iron (II) sulphide
ii)
Element is a simple substance that cannot be broken down into smaller parts or changed into another substance or a substance whose atoms are of the same kind
iii)
The name given to a solid mixture is an alloy
6.
(a)
(i)
Define Pressure
(ii)
Explain why it is important to sharpen a knife before use.
(b)
(i)
State two differences between metals and non-metals.
(ii)
What is an alloy?
(ii)
Mention the components of each of the following alloys:
(α)
steel;
(β)
brass.
(c)
Mention three conditions suitable for rearing tilapia in a fishpond.
(d)
Explain how the streamlined body of a bony fish enables it to live successfully in water.
(a)
(i)
Pressure is defined as force per unit area applied in a direction perpendicular/normal to the surface of the object.
OR
Pressure =
(ii)
Why it is important to sharpen a knife before use
When a knife is sharpened, the cutting edge becomes smaller so that with a little force applied, a larger pressure is exerted for cutting to be easier.
(b)
(i)
Differences between metals and non-metals
| # | Metal | Non-metal | |||
| 1. | Normally solid | Can be solid or liquid or gas | |||
| 2. | Corrosive | Non corrosive | |||
| 3. | Attracted by magnet | Not attracted by magnet | |||
| 4. | Conducts electricity | Does not conduct electricity/poor conductor of electricity | |||
| 5. | Conducts heat/good conductor of heat | Does not conduct heat/poor conductor of heat | |||
| 6. | Malleable | Not malleable | |||
| 7. | Ductile | Not ductile/Brittle | |||
| 8. | High density | Low density | |||
| 9. | High melting point | Low melting point | |||
| 10. | Has shinning/lustre surface | Has dull surface | |||
| 11. | Gives out electrons (forms cations) as reducing agent | Receives/accepts electrons (forms anions) as oxidizing agent | |||
| 12. | High tensile strength | Low tensile strength |
(ii)
An alloy is a uniform/homogeneous mixture of a metal and another metal or a non-metal.
(ii)
Components of alloys
(α)
steel → carbon and iron
(β)
brass → copper and zinc
(c)
Conditions suitable for rearing tilapia in a fishpond
1. Presence of dissolved oxygen
2. Ideal/suitable/favourable pH
3. Suitable temperature
4. Suitable salt concentration/salinity
5. Suitable depth of water/pond depth
6. Non-polluted/non-contaminated/clean water
(d)
The streamlined body of a bony fish enables it to move freely to cut its way through water easily with least resistance from water molecules.