Term pack

Grade 8 Science

Name: ________________________

Skills in this pack

Forces: contact and non-contact
Magnetic and heating effects of current
The particulate nature of matter
Elements, compounds and mixtures
Solutes, solvents and solutions
Mirrors and lenses
The cell, the basic unit of life
Microorganisms around us
Ecosystems and food chains
Winds, storms and cyclones

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Grade 8 Science · 1 of 10

Forces: contact and non-contact

Sort forces by whether they need the objects to touch, read a spring balance, and keep weight and mass apart.

1.A ball is thrown straight up. Starting from The object moves straight up, put what happens next back into order.
- It stops momentarily at the top
- It falls back down, its speed increasing
- The object moves straight up
- Its speed goes on decreasing
2.A box is pushed to the right across a table. In which direction does friction act on it?
- a) Downwards, into the table
- b) Upwards, away from the table
- c) To the right, along with the push
- d) To the left, opposite to the way the box is moving
3.A spring balance measures up to 10 N, with a bigger mark at each newton. Which mark is at 6 N?
Mark the line with an X.
4.A 1 kg object weighs 10 N on the Earth, 25.4 N on Jupiter, 9 N on Venus and 3.8 N on Mars. What does the same object weigh on the Moon?
- a) 9 N
- b) 3.8 N
- c) 10 N
- d) 1.6 N
5.What is the SI unit of force called? Give the one word.
6.An object is carried to the Moon. Which of these changes, and which stays put?
- a) Its weight changes; its mass stays the same
- b) Its mass changes; its weight stays the same
- c) Neither changes
- d) Both change
7.The chapter explains why friction is greater on a rough surface. What is its explanation?
- a) Rough surfaces attract objects magnetically
- b) Rough surfaces are heavier than smooth ones
- c) Rough surfaces heat up faster, and heat resists motion
- d) Irregularities on the two surfaces lock into each other and oppose one sliding over the other
8.An object placed in a liquid floats rather than sinks. What does the chapter say about the two forces on it?
- a) The buoyant force and the gravitational force are equal
- b) The gravitational force is greater than the buoyant force
- c) There is no gravitational force acting on a floating object
- d) The buoyant force acts downwards and the gravitational force upwards

Forces: contact and non-contact · Grade 8 Science · www.arenapublications.com/learn

Grade 8 Science · 2 of 10

Magnetic and heating effects of current

Explain how a current makes a magnet and how it makes heat, and say what changes the strength of an electromagnet.

1.Why should a used battery go to an e-waste facility rather than into the household bin?
- a) A used battery is completely inert and so has no value
- b) It can still contain acids and metals that may cause fires or harm the environment
- c) It will start working again once it has been sorted
- d) Household bins are too small for batteries
2.The north pole of a magnetic compass is attracted towards end A of an electromagnet. Which pole is end A?
- a) Both at once
- b) Neither — an electromagnet has no poles
- c) North
- d) South
3.The chapter lists what the heat generated in a wire depends on. Which list is right?
- a) The temperature of the room the circuit is in
- b) The color of the wire and the shape of the switch
- c) The material of the wire and nothing else
- d) The material, thickness and length of the wire, and how long the current flows
4.Nichrome, rather than copper, is used in electric heating devices. Why?
- a) Nichrome conducts electricity better than copper
- b) Nichrome is cheaper than copper
- c) For a wire of the same size and length, nichrome offers higher resistance and so gives more heat
- d) Nichrome does not conduct electricity
5.Sort these two kinds of cell by whether they can be used again after they run down.
Groups: Single use · Recharged and reused many times
- Dry cell
- Rechargeable battery
6.Why does a lifting electromagnet on a crane suit a scrapyard better than an ordinary magnet would?
- a) It picks up materials that are not magnetic
- b) The operator can drop the load by switching the current off
- c) It works without any electricity supply
- d) It is lighter than an ordinary magnet of the same size
7.A nichrome wire in a circuit gets warm. What is happening inside it?
- a) The current rubs against the sides of the wire, and friction warms it
- b) The wire is absorbing heat from the air around it
- c) The cell is hot, and the heat travels along the wire
- d) The wire resists the flow of current, and that resistance turns some electrical energy into heat
8.In a dry cell, which part acts as the negative terminal?
- a) The metal cap on top
- b) The paste-like electrolyte
- c) The carbon rod at the center
- d) The zinc container

Magnetic and heating effects of current · Grade 8 Science · www.arenapublications.com/learn

Grade 8 Science · 3 of 10

The particulate nature of matter

Explain the three states of matter by how tightly their particles are held and how much space sits between them.

1.Grinding a stick of chalk into fine powder is which kind of change, and why?
- a) A physical change, because heat was needed to do it
- b) A chemical change, because the chalk cannot be put back together
- c) A physical change, because the chalk is still chalk and just the size of each speck has altered
- d) A chemical change, because the powder is a new substance
2.In the chapter's table, ice melts at 0 °C and urea at 133 °C. The third solid listed melts at 1538 °C. Which solid is that? Give the one word.
3.Now sort the same three by how much room sits between their particles.
Groups: Least space between particles · A little more space than in a solid · Most space between particles
- Gas
- Liquid
- Solid
4.Match each solid from the chapter's table to its melting point, in degrees Celsius.
- Ice
- Urea
- Iron
- 133
- 1538
- 0
5.Liquids and gases share two properties that solids do not: they flow, and they do not hold a fixed shape. What are the two of them called together?
- a) Mixtures
- b) Fluids
- c) Vapors
- d) Solutions
6.A solid is heated until it melts. Put the four stages back into order.
- The solid turns into a liquid
- The particles vibrate more vigorously
- The vibrations grow strong enough that particles leave their positions
- The interparticle forces of attraction weaken
7.An incense stick is lit in one corner of a room and the fragrance is soon noticed across it. What does that show?
- a) Smoke is heavier than air and rolls along the floor
- b) Air particles stand still while the fragrance particles push past them
- c) The fragrance particles are pulled towards people
- d) The particles of air are moving constantly and carry the fragrance particles with them
8.Match each state of matter to what it does about shape and volume.
- A solid
- A liquid
- A gas
- keeps neither shape nor volume, and spreads through the space available
- keeps a definite shape and a definite volume
- keeps a definite volume but takes the shape of its container

The particulate nature of matter · Grade 8 Science · www.arenapublications.com/learn

Grade 8 Science · 4 of 10

Elements, compounds and mixtures

Tell an element from a compound from a mixture, and say which of them can be taken apart by physical means.

1.Sugar heated in a boiling tube turns brown, then black, and droplets of water appear near the open end. What does that show about sugar?
- a) It is an element, since carbon is left behind
- b) It is a mixture of carbon and water stirred together
- c) It is a metal, since it darkens on heating
- d) It is a compound, made of carbon, hydrogen and oxygen
2.Sort these substances into the three kinds the chapter names.
Groups: Element · Compound · Mixture
- Brass
- Air
- Gold
- Water
- Sulfur
- Sodium chloride
3.Match each test done on iron and sulfur to what was seen.
- A magnet is moved over the stirred mixture of iron filings and sulfur powder
- A magnet is moved over the black mass left after heating them together
- Dilute hydrochloric acid is added to the stirred mixture
- Dilute hydrochloric acid is added to the black mass
- the iron filings are drawn out, so the two can be separated
- nothing is drawn out, because a new substance has formed
- a colorless gas with no smell comes off and burns with a pop
- a colorless gas with a rotten egg-like odor comes off
4.A packet of ghee is labeled 'pure'. A scientist looks at it and calls it impure. Why the disagreement?
- a) In science, pure means made of a single substance, while in everyday use it means unadulterated
- b) In science, any substance sold in a packet counts as impure
- c) The scientist thinks the ghee has had something cheaper added to it
- d) In science, pure means safe to eat, and the ghee is not
5.These are mixtures. Sort them by whether you could pick out the separate components by eye or with a magnifying glass.
Groups: Uniform mixture · Non-uniform mixture
- Stainless steel
- Air
- Sprout salad
- Sugar dissolved in water
6.Two substances are stirred together and each keeps its own properties, with no chemical reaction between them. What has been made?
- a) A pure substance
- b) An element
- c) A mixture
- d) A compound
7.What does the chapter say a mineral is?
- a) A mixture of two or more rocks
- b) A metal that has been extracted from a rock
- c) Any solid substance that people dig out of the ground
- d) A natural solid substance with a fixed chemical composition, usually a compound and occasionally a pure element
8.Elements divide into two families. Sort these into theirs.
Groups: Metal · Non-metal
- Oxygen
- Aluminum
- Gold
- Sulfur
- Iron
- Carbon

Elements, compounds and mixtures · Grade 8 Science · www.arenapublications.com/learn

Grade 8 Science · 5 of 10

Solutes, solvents and solutions

Name the solute and the solvent in a solution, tell a saturated solution from an unsaturated one, and say how temperature changes what will dissolve.

1.For most solids dissolving in a liquid, what does raising the temperature do to the solubility?
- a) It increases it for salts and decreases it for sugars
- b) It leaves it unchanged
- c) It decreases it
- d) It increases it
2.The greatest amount of solute a fixed quantity of solvent will dissolve at a particular temperature has a one-word name. What is it?
3.Match each word to what it names.
- Solute
- Solvent
- Solution
- Solubility
- the substance that does the dissolving
- the substance that dissolves
- the most solute a fixed quantity of solvent will take at a given temperature
- the uniform mixture the two of them make
4.Which is the more concentrated solution: 2 spoons of salt in 100 mL of water, or 4 spoons in 50 mL?
- a) Neither, because concentration applies to gases rather than solids
- b) 4 spoons in 50 mL, since more solute sits in less solution
- c) They are equally concentrated, since both use salt and water
- d) 2 spoons in 100 mL, since there is more water to spread through
5.Which statement about a saturated solution is the right one?
- a) It has dissolved less solute than an unsaturated solution
- b) It can still dissolve more solute at that temperature
- c) No more solute can be dissolved into it at that temperature
- d) It forms at high temperatures and nowhere else
6.Each sip of a homemade oral rehydration solution tastes the same as the last. Why?
- a) The sugar and salt cancel out each other's taste
- b) The water dilutes both of them until neither can be tasted
- c) The sugar and salt are evenly distributed through the whole of the water
- d) The sugar settles at the bottom and the salt stays at the top
7.Gases behave the other way round from solids. What happens to the solubility of a gas in water as the water warms up?
- a) It decreases
- b) It stays the same
- c) It increases
- d) It increases up to 50 °C and decreases after that
8.Spoons of salt are stirred into a glass of water one after another. Put the four stages back into order.
- A spoon is added that does not fully dissolve
- The undissolved salt settles at the bottom
- More spoons go in and still dissolve
- The first spoon of salt dissolves completely

Solutes, solvents and solutions · Grade 8 Science · www.arenapublications.com/learn

Grade 8 Science · 6 of 10

Mirrors and lenses

Tell concave from convex for both mirrors and lenses, use the laws of reflection to find an angle, and say which of them gathers a beam and which spreads it.

1.Parallel beams of light fall on each of these. Sort them by what happens to the beams afterwards.
Groups: Converges the beam · Diverges the beam
- Concave lens
- Convex mirror
- Concave mirror
- Convex lens
2.The angle between the normal and the incident ray has a three-word name. What is it?
3.A pen cap is held close to a concave mirror and then moved slowly away. What happens to its image?
- a) It stays exactly the same size and the right way up
- b) It starts upright and enlarged, then becomes inverted and gets smaller
- c) It stays inverted and gets steadily larger
- d) It stays upright and enlarged the whole way
4.Sunlight is directed onto a sheet of paper with a concave mirror, and the paper is moved until a small bright spot forms. What happens next, and why?
- a) The paper can start to burn, because the mirror has concentrated the sunlight onto that point
- b) The paper cools down, because the mirror has taken the heat out of the light
- c) Nothing happens, because reflected light carries no heat
- d) The spot spreads out, because a concave mirror scatters light
5.A ray of light strikes a mirror at an angle of 35° to the normal. What is the angle of reflection, in degrees? Answer with a number.
6.A ray strikes a mirror, making an angle of 40° with the normal. What angle does the reflected ray make with the mirror surface, in degrees? Answer with a number.
7.The laws of reflection were worked out with a plane mirror. Which mirrors do they hold for?
- a) Plane mirrors and nothing else
- b) Curved mirrors, but not plane ones
- c) Plane and concave mirrors, but not convex ones
- d) Plane, concave and convex alike
8.Why is a convex mirror, rather than a plane one, fitted as a vehicle's side-view mirror?
- a) It shows a much wider area of the road behind
- b) It shows the traffic behind the right way up, which a plane mirror cannot
- c) It shows the traffic behind at a larger size
- d) It is cheaper to make than a plane mirror of the same size

Mirrors and lenses · Grade 8 Science · www.arenapublications.com/learn

Grade 8 Science · 7 of 10

The cell, the basic unit of life

Name the parts of a cell and what each does, tell a plant cell from an animal cell, and put the levels of organization in order.

Before you start

Six parts of a plant cell are marked out here. Take them one at a time, and each will name itself.

1. Cell wall
2. Cell membrane
3. Cytoplasm
4. Vacuole
5. Chloroplast
6. Nucleus

The cell wall and the chloroplasts are the two parts you would not find if this were an animal cell.

1.Why do cells in a multicellular body take on specialized jobs rather than each doing everything?
- a) A cell can carry out one process and no more
- b) Specialized cells need no nucleus
- c) Cells of the same shape cannot sit next to one another
- d) Specializing and then cooperating improves the organism's chance of survival
2.Put the levels of organization in a living body in order, from the smallest upwards.
- Tissue
- Organ
- Organism
- Organ system
- Cell
3.Which part is present in an onion peel cell but absent from a human cheek cell?
- a) The cell wall
- b) The nucleus
- c) The cell membrane
- d) The cytoplasm
4.Match each part of a cell to the job it does.
- Cell membrane
- Cytoplasm
- Nucleus
- Cell wall
- the place where most life processes happen
- an extra outer layer that stiffens the cell
- regulates what the cell does and how it grows
- separates one cell from the next and lets material in and out
5.Match each level of organization to what it is built from.
- Tissue
- Organ
- Organ system
- different tissues working together
- several organs carrying out one major body function
- a group of similar cells
6.How does the vacuole in a plant cell differ from those in an animal cell?
- a) The vacuole in a plant cell is filled with chlorophyll
- b) The plant cell has one large vacuole; an animal cell's are usually absent or small
- c) The plant cell has many tiny vacuoles; an animal cell has one large one
- d) Vacuoles are found in animal cells and not in plant cells
7.The life of a complex organism begins with a single cell. Which one?
- a) A muscle cell
- b) A cheek cell
- c) A nerve cell
- d) The egg
8.Three kinds of human cell, sorted by their shape under the microscope.
Groups: Spindle-shaped · Long and branched · Thin and flat
- Muscle cell
- Cheek cell
- Nerve cell

The cell, the basic unit of life · Grade 8 Science · www.arenapublications.com/learn

Grade 8 Science · 8 of 10

Microorganisms around us

Name the main groups of microorganisms and say what they do for soil, food and crops.

1.Manure forms best under certain conditions. Which does the chapter name?
- a) An optimal temperature and an appropriate moisture level
- b) Freezing temperatures and standing water
- c) Direct sunlight and dry soil
- d) Complete darkness and dry conditions
2.Match each microorganism to the job it does for us.
- Yeast
- Lactobacillus
- Rhizobium
- makes bread and cake dough rise
- traps nitrogen from the air for legume plants
- turns milk into curd
3.Sort these microorganisms by the group the chapter puts them in.
Groups: Protozoa · Fungi · Algae
- Yeast
- Paramecium
- Amoeba
- Spirulina
- Bread mold
4.Fruit and vegetable peels are buried in a pot of garden soil. Three weeks later they have become a dark crumbly material. What is it, and what made it?
- a) Manure, made by the soil dissolving the peels
- b) Charcoal, made by the peels being pressed under the soil
- c) Compost, made by the peels drying out in the heat
- d) Manure, made by fungi and bacteria breaking the peels down
5.Bacteria and fungi living without oxygen can break down plant and animal waste and release a mixture of gases. What is that mixture called, and what is it mainly?
- a) Marsh gas, mainly carbon monoxide
- b) Biogas, mainly carbon dioxide with a high proportion of methane
- c) Manure gas, mainly hydrogen
- d) Biogas, mainly oxygen with a little nitrogen
6.Where does the chapter say microorganisms can be found?
- a) In water, in soil, in air, and inside the bodies of plants and animals
- b) In soil and air, but not inside living bodies
- c) In water and soil, but not in air
- d) Chiefly in food that has been left out to rot
7.Microalgae live in water, soil, air and on trees, and make their own food using sunlight. What does the chapter say they release while doing so?
- a) The nitrogen that legumes take up
- b) The methane in biogas
- c) More than half of the Earth's carbon dioxide
- d) More than half of the Earth's oxygen supply
8.Some microorganisms live in hot water springs and snow-cold zones. What does that tell you about them as a group?
- a) They live in extreme conditions and cannot survive moderate ones
- b) They can live at high temperatures but not at low ones
- c) They can live in extreme conditions as well as moderate ones
- d) They cannot survive anywhere that a plant cannot grow

Microorganisms around us · Grade 8 Science · www.arenapublications.com/learn

Grade 8 Science · 9 of 10

Ecosystems and food chains

Separate the living and non-living parts of a habitat, build a food chain, and name the three ways two organisms can live together.

1.In the chain grass → grasshopper → frog → snake, the frogs disappear. What happens to the grasshoppers and the snakes?
- a) Both stay the same, because the grass is unaffected
- b) Both increase, because one fewer animal is competing for space
- c) Grasshoppers increase, because nothing is eating them; snakes decrease, because their food has gone
- d) Grasshoppers decrease and snakes increase
2.In the food chain grass → grasshopper → frog → snake, which one is the producer?
- a) Grasshopper
- b) Snake
- c) Frog
- d) Grass
3.Food chains in an ecosystem are not really separate. What are they, taken together?
- a) A population, because the chains hold organisms of the same kind
- b) A trophic level, because each chain occupies one level
- c) A community, because the chains share a habitat
- d) A food web, because an organism may be eaten by two or more kinds of organism
4.Carrying pollen from the stamens to the carpels — by wind, water, insects, bats or birds — has a one-word name, and fruits and seeds depend on it. What is it?
5.Sort what you would find in a pond or a forest by whether it is living or not.
Groups: Biotic · Abiotic
- Grass
- Water
- Soil
- Sunlight
- Fish
6.Match each pair of organisms to the kind of relationship they have.
- Honeybees and flowers
- An orchid on a tree branch
- A tick on a dog
- parasitism
- mutualism
- commensalism
7.Put these four levels of nature in order, from the smallest upwards.
- Population
- Individual
- Ecosystem
- Community
8.Put this grassland food chain in order, from what is eaten first to what eats last.
- Frog
- Snake
- Eagle
- Grass
- Grasshopper

Ecosystems and food chains · Grade 8 Science · www.arenapublications.com/learn

Grade 8 Science · 10 of 10

Winds, storms and cyclones

Trace a wind back to a difference in air pressure, and follow the chain from a rising column of warm air to a thunderstorm and a cyclone.

1.High-speed winds blow across the roof of a house. What happens to the air pressure above the roof, and why can that lift a weak roof off?
- a) It drops below the pressure underneath, and the roof is pulled down
- b) It stays the same, and the wind lifts the roof by hitting it directly
- c) It drops below the pressure underneath the roof, and the roof is pushed up from below
- d) It rises above the pressure underneath the roof, and the roof is pushed up from above
2.The region of lowest pressure at the center of a cyclone, where the wind is calm while the surrounding region is battered, is called the ___ of the cyclone. Give the one word.
3.A cyclone that has come ashore gradually weakens. Why?
- a) The land is colder than the sea, so it freezes the cyclone
- b) Buildings on land block the wind and slow it down
- c) Its source of warm moist air from the ocean has been cut off
- d) The Earth rotates more slowly over land than over sea
4.Air is normally an electrical insulator, keeping opposite charges in a cloud apart. What has to happen before lightning can flash?
- a) The rain stops, because water carries the charge away
- b) The air cools until it turns into a conductor of electricity
- c) The cloud touches the ground so the charges can meet
- d) The charge builds up so much that the insulating property of the air breaks down
5.Lightning heats the air around it very rapidly. What does that produce?
- a) A second flash a moment later
- b) Thunder, as the air expands and makes a loud sound
- c) Hail, as the heated air freezes on cooling
- d) Rain, as the heated air condenses
6.Put the steps that end in a flash of lightning back into the order the chapter gives them.
- A bright flash of lightning is seen
- The ground below becomes positively charged
- The insulating property of air breaks down
- Strong winds rub water droplets against ice particles
- Charge separates, leaving the lower part of the cloud negative
7.Match each name to what the chapter says it is.
- Storm
- Thunderstorm
- Cyclone
- Eye of the cyclone
- a storm that also brings lightning and thunder
- a spinning system of clouds, winds and rain around a very low-pressure center
- strong winds accompanied by rain
- the calm center, where the pressure is at its lowest
8.A lightning conductor is a metallic rod fixed to a building, pointed at the top and buried deep in the ground at the bottom. What is it for?
- a) To store the charge safely inside the building
- b) To give electric charge an easy path into the ground
- c) To attract the charge away from the ground into the sky
- d) To stop lightning forming in the clouds above the building

Winds, storms and cyclones · Grade 8 Science · www.arenapublications.com/learn

Answer keys — Grade 8 Science

In the same order as the worksheets.