Primary 3 Science Materials Quiz

Primary 3 Science Quiz – Materials

Answer Key

Section A: Multiple-Choice Questions (1 × 10 = 10 marks)

1. Answer: (c) Wood
Wood is a natural material that comes from trees. Plastic, nylon, and steel are man-made materials.

2. Answer: (c) transparent
A transparent material allows most light to pass through it so that objects behind it can be seen clearly. Opaque materials do not allow light through; translucent materials allow some light through but objects cannot be seen clearly.

3. Answer: (b) It is waterproof and flexible.
Rubber is waterproof (keeps water out) and flexible (can bend without breaking), making it suitable for tyres that need to grip the road and absorb shocks.

4. Answer: (c) Metal
Metal is a good conductor of heat, meaning heat passes through it quickly. Wood, plastic, and cloth are poor conductors of heat (insulators).

5. Answer: (c) Glass rod
Glass is brittle, meaning it breaks or shatters when bent or struck. Rubber bands, copper wires, and plastic rulers are flexible and bend without breaking.

6. Answer: (b) Glass
Glass is made by heating sand (silica) at very high temperatures. Paper comes from wood, cotton comes from cotton plants, and leather comes from animal skin.

7. Answer: (c) It is strong and hard.
Metals are generally strong, hard, shiny, and good conductors of heat and electricity. They are not dull, soft, or poor conductors.

8. Answer: (b) waterproof
Plastic does not absorb water, so it keeps the person dry in the rain. This property is called being waterproof.

9. Answer: (c) Wool
Wool comes from the fleece of sheep (animals). Cotton comes from cotton plants, wood comes from trees, and glass is made from sand.

10. Answer: (d) A school chair with metal legs and a plastic seat
This object is made from two different materials — metal and plastic. The other objects are each made from a single material.

Section B: Short-Answer Questions (20 marks)

11. State two properties of wood. (2 marks)
Award 1 mark for each correct property, up to 2 marks.

Accept any two of the following (or other valid properties):

• Wood is hard.
• Wood is strong.
• Wood is rigid / does not bend easily.
• Wood is a poor conductor of heat (insulator).
• Wood is opaque.
• Wood is waterproof (to a degree / does not soak up water easily).

Common mistake: Students may write "wood is flexible" — this is incorrect for most types of wood used in furniture.

12. Complete the table. (4 marks)
Award 1 mark for each correct answer.

Marking notes:

• (a) Sponge is soft — it can be squashed easily.
• (b) Steel is rigid — it does not bend easily.
• (c) Rubber is flexible — it can be bent and stretched.
• (d) Glass is hard — it cannot be scratched or dented easily (though it is brittle).

13. Explain why a cooking pot is usually made of metal while its handle is made of plastic. (3 marks)
Award marks as follows:

• 1 mark: The pot is made of metal because metal is a good conductor of heat / heat passes through metal easily, so the food heats up quickly.
• 1 mark: The handle is made of plastic because plastic is a poor conductor of heat (insulator) / heat does not pass through plastic easily.
• 1 mark: This prevents the person's hand from getting burned / keeps the handle cool to hold.

Accept equivalent wording. Students must link the property of the material to its function.

14. Natural or man-made? (4 marks)
Award 1 mark for each correct tick.

Explanation:

• Cotton comes from cotton plants → natural.
• Nylon is made in factories from chemicals → man-made.
• Leather comes from animal skin → natural.
• Polyester is a synthetic material made in factories → man-made.

15. Which sock should she choose to stay cool? Explain. (3 marks)
Award marks as follows:

• 1 mark: She should choose the white sock.
• 1 mark: White / light-coloured materials reflect most of the sunlight / heat.
• 1 mark: Black / dark-coloured materials absorb more heat, making her feel warmer.

Accept equivalent reasoning. The key idea is that lighter colours reflect heat and keep things cooler.

16. Name the material and give a reason. (4 marks)
Award 1 mark for each correct material and 1 mark for each valid reason.

(i) Window:

• Material: Glass
• Reason: Glass is transparent / allows light to pass through / you can see through it.

(ii) Rope:

• Material: Nylon / Cotton / Any suitable fibre material
• Reason: It is strong / flexible / does not break easily when pulled.

Accept other valid materials and reasons (e.g., rope made from hemp — strong and flexible).

Section C: Structured / Application Questions (10 marks)

17. Designing a water bottle. (3 marks)

(a) Recommended material and two reasons. (2 marks)
Award 1 mark for a suitable material and 1 mark for two valid reasons.

Recommended material: Plastic (accept metal with valid reasons)

Reasons for plastic (any two):

• Plastic is light / easy to carry.
• Plastic is waterproof / does not leak.
• Plastic is flexible / does not break easily when dropped.
• Plastic is transparent (some types) / you can see the water level.

(b) One disadvantage of glass. (1 mark)
Accept any one:

• Glass is heavy.
• Glass is brittle / breaks easily when dropped.
• Glass can cut someone if it breaks.

18. Identifying materials X, Y, and Z. (3 marks)

(a) Material X is most likely plastic. (2 marks)
Award 1 mark for identifying X and 1 mark for a valid explanation.

Explanation: Plastic is strong, waterproof, flexible, and light — all properties listed for Material X.

(b) Material Y is most likely metal. (1 mark)
Reason: Metal is strong, hard, heavy, and conducts heat — matching the properties of Material Y.

Note: Material Z is likely glass (breaks easily, transparent, rigid).

19. Water drop test. (3 marks)

(a) Waterproof material(s): A and C (1 mark)
Explanation: Materials A and C caused the water drop to stay on the surface in a dome shape, meaning the water was not absorbed — they are waterproof.

(b) Most suitable material for an umbrella: Material A or C (1 mark for correct material, 1 mark for explanation)
Explanation: An umbrella needs to be waterproof so that rain does not pass through it and the person stays dry. Materials A and C are waterproof because the water drop stayed on the surface and was not soaked in.

Accept either A or C as the answer.

20. Identifying materials from objects. (2 marks)

(a) Object made from a material that comes from a plant: Object 1 (cotton T-shirt) (1 mark)
Cotton comes from the cotton plant.

(b) Object made from a material that is a good conductor of heat: Object 2 (metal key) (1 mark)
Metal is a good conductor of heat.

Mark Summary

This quiz was generated using syllabus-aligned LLM-inferred templates. It is designed to complement the Primary 3 Science syllabus on Materials and does not claim to be derived from past-year exam papers.