Classification of materials based on properties
Different materials have different properties, so they are used for different purposes.
- Very strong and hard
- Waterproof (does not let water through)
- Sinks in water (heavier than water)
- Good conductor of heat and electricity
- Generally strong
- Floats on water (lighter than water)
- Poor conductor of heat and electricity
- Waterproof
- Sinks in water
- Poor conductor of heat and electricity
- Transparent (allows light to pass through)
- Strong yet light
- Floats on water
- Waterproof
- Poor conductor of heat and electricity
- Waterproof
- Sinks in water
- Poor conductor of electricity
- Often sinks when soaked in water
- Flexible and can be folded
- Poor conductor of heat and electricity
- Not waterproof (lets water through)
- Flexible and elastic
- Waterproof
- Poor conductor of electricity
- Can be soft or firm depending on type
Properties of Materials
How materials behave with magnets, heat and different forces.
- Some materials (for example iron and steel) can be pulled by a magnet.
- Many other materials, like wood, glass, plastic and fabric, are not attracted to a magnet.
- Good conductors of heat let heat pass through them quickly. Most metals are good conductors.
- Poor conductors of heat (insulators) let heat pass through them slowly, such as ceramic, glass, plastics, fabric, wood and rubber.
- Stronger materials can take a larger pulling or pressing force before they break.
- Many metals (like steel) and ceramics are stronger than fabric, wood and rubber.
- Flexible materials can be bent without breaking, such as fabric, some plastics, some wood, paper and rubber.
- Glass and ceramics are not flexible and break easily when we try to bend them.
Properties of Materials – Practice Quiz
Read the question and options. Click to reveal the correct answer.
1. Which material is MOST likely to be attracted to a magnet?
A. Glass B. Plastic C. Iron D. Wood
Answer: C – Iron is a magnetic material.
2. Which statement about magnetic materials is TRUE?
A. All metals are magnetic. B. Only plastic is magnetic.
C. Iron and steel are magnetic materials. D. Wood is magnetic.
Answer: C – Iron and steel can be attracted to magnets.
3. Which material is a good conductor of heat?
A. Rubber B. Ceramic C. Metal D. Fabric
Answer: C – Metals allow heat to pass through quickly.
4. A saucepan handle is usually made of plastic because…
A. Plastic is magnetic. B. Plastic is waterproof.
C. Plastic is a poor conductor of heat. D. Plastic is stronger than metal.
Answer: C – Plastic is a poor conductor of heat, so it keeps our hands safer.
5. Which material is the STRONGEST?
A. Fabric B. Rubber C. Ceramic D. Paper
Answer: C – Ceramic (and metals like steel) are much stronger than fabric, rubber and paper.
6. Which material can be bent WITHOUT breaking?
A. Glass B. Ceramics C. Fabric D. Ceramic tiles
Answer: C – Fabric is flexible and can be bent without breaking.
7. Which statement about flexibility is TRUE?
A. Glass is flexible. B. Ceramics can be bent.
C. Rubber is flexible. D. Metals can never bend.
Answer: C – Rubber can bend and stretch without breaking.
8. Which is a POOR conductor of heat?
A. Aluminium B. Steel C. Wood D. Copper
Answer: C – Wood does not allow heat to pass through quickly.
9. Why does a metal spoon feel hot quickly when placed in hot soup?
A. Metal is waterproof. B. Metal is magnetic.
C. Metal is a good conductor of heat. D. Metal is flexible.
Answer: C – Metal is a good conductor of heat, so heat travels quickly from the soup to the spoon.
10. Which material is BOTH waterproof and strong?
A. Fabric B. Rubber C. Metal D. Paper
Answer: C – Metal is strong and does not let water pass through.
11. Classify: Magnetic vs Non-magnetic – iron, steel, glass, plastic, wood.
Suggested answer:
Magnetic: iron, steel
Non-magnetic: glass, plastic, wood
12. Classify by heat conductivity – metal, aluminium, glass, rubber, wood.
Suggested answer:
Good conductors of heat: metal, aluminium
Poor conductors of heat: glass, rubber, wood
13. Classify by strength – steel, ceramic, fabric, rubber.
Suggested answer:
Strong: steel, ceramic
Less strong: fabric, rubber
14. Classify by flexibility – rubber, fabric, paper, glass, ceramic.
Suggested answer:
Flexible: rubber, fabric, paper
Not flexible: glass, ceramic
15. Match the object to its property – metal pan, plastic handle, rubber hose.
Suggested answer:
Needs to conduct heat: metal pan
Needs to be a poor conductor of heat: plastic handle
Needs to be flexible: rubber hose
16. Why is a kettle body often made of metal?
Answer: Metal is a good conductor of heat, so it heats the water quickly and evenly.
17. Why is the wire inside a plug coated with rubber?
Answer: Rubber is a poor conductor of electricity, so it helps protect us from electric shock.
18. Why is glass used for windows?
Answer: Glass is transparent, so it allows light to pass through while still blocking wind and rain.
19. Why is fabric NOT suitable for making a raincoat?
Answer: Fabric is not waterproof, so it lets water pass through and would not keep us dry.
20. Why is steel used to make the structure of a bridge?
Answer: Steel is very strong and can withstand large forces and heavy loads without breaking.
Materials in Everyday Life
Everyday objects are made from materials chosen for their special properties.
- The metal base is a good conductor of heat, so heat from the heater moves quickly to the cloth.
- The plastic handle is a poor conductor of heat, protecting our hand from getting burnt.
- Inside the cord, copper wire carries electricity, while the plastic covering acts as an electrical insulator to prevent electric shock.
- The plastic coating around the wire is flexible, so the wire can bend around corners.
- The plastic handle of the iron is made from a stiffer plastic so that we can press the iron down firmly on the cloth.
- The raincoat is made of waterproof plastic, so rainwater cannot reach the boy’s clothes.
- The plastic is flexible, allowing the boy to move and play easily.
- Because the plastic is clear, light can pass through and we can still see what he is wearing.
- The coconut has a waterproof outer covering that stops water from soaking into the husk.
- Its fibrous husk traps air, so the coconut can float on water.
- Floating allows the coconut to be carried by waves to new places, helping the seed to be dispersed away from the parent plant.
- Glass is transparent, so it is used for windows to let light into the room.
- In cold countries, two layers of glass are used with air trapped between them.
- Air is a poor conductor of heat, so it helps reduce heat loss from the warm room to the cold outside.
- Rubber tyres are placed along docks and boat sides to protect the boats.
- Rubber is strong enough to withstand large forces when boats knock against the dock.
- Rubber is also flexible, so it can squash and spring back, helping to absorb the kinetic energy of the moving boat.
Materials in Everyday Life – Practice Quiz
Read each question. Click to reveal the answer and explanation.
1. Why is the base of an electric iron made of metal?
A. Metal is waterproof. B. Metal is magnetic.
C. Metal is a good conductor of heat. D. Metal is flexible.
Answer: C – Metal is a good conductor of heat, so heat from the heater can reach the clothes quickly.
2. The handle of an electric iron is usually made of plastic because…
A. Plastic is a good conductor of heat. B. Plastic is a poor conductor of heat.
C. Plastic is magnetic. D. Plastic traps air.
Answer: B – Plastic is a poor conductor of heat, so it helps to protect our hand from being burnt.
3. Inside an electric wire, the part that carries electricity is the…
A. plastic coating B. copper wire
C. wooden core D. rubber outer layer
Answer: B – The copper wire inside is an electrical conductor and carries electricity.
4. Why is the plastic coating around a wire important?
A. It helps the wire float on water. B. It makes the wire magnetic.
C. It acts as an electrical insulator. D. It makes the wire a good conductor of heat.
Answer: C – The plastic coating is an electrical insulator that helps prevent electric shock.
5. Why is a raincoat made of plastic and not of fabric?
A. Plastic is magnetic. B. Plastic is waterproof.
C. Plastic is transparent. D. Plastic is a good conductor of heat.
Answer: B – Plastic used for raincoats is waterproof, so it keeps the person dry.
6. A clear plastic raincoat allows us to see the clothes underneath because plastic is…
A. opaque B. translucent C. transparent D. magnetic
Answer: C – The raincoat is made of transparent plastic, which allows most light to pass through.
7. Why can a coconut float on water?
A. Its shell is transparent. B. Its husk traps air.
C. Its shell is a good conductor of heat. D. Its husk is magnetic.
Answer: B – The coconut has a fibrous husk that traps air, allowing it to float on water.
8. Why is glass suitable for making windows?
A. Glass is waterproof only. B. Glass is a poor conductor of heat only.
C. Glass is transparent. D. Glass is flexible.
Answer: C – Glass is transparent, so it allows light to enter the room.
9. In a double-glazed window, air is trapped between two glass panes because…
A. air is a good conductor of heat. B. air is a poor conductor of heat.
C. air is magnetic. D. air makes the window transparent.
Answer: B – Air is a poor conductor of heat, so it helps to reduce heat loss.
10. Why are rubber tyres used at the sides of docks where boats come in?
A. Rubber is transparent. B. Rubber is waterproof only.
C. Rubber is strong and flexible. D. Rubber is a good conductor of heat.
Answer: C – Rubber is strong and flexible, so it can withstand and absorb the force when boats bump against the dock.
11. Explain why it is safer to touch the plastic handle of an iron than its metal base.
Answer: The plastic handle is a poor conductor of heat, so less heat is transferred to our hand. The metal base is a good conductor of heat and can be very hot.
12. Give one reason why a raincoat should be flexible.
Answer: If the raincoat is flexible, the person wearing it can move, walk and play comfortably without the material tearing.
13. How does the structure of a coconut help the seed move away from the parent plant?
Answer: The fibrous husk traps air, so the coconut can float on water. It can then be carried by waves to new places away from the parent plant.
14. Why is it useful to trap air between two layers of glass in cold countries?
Answer: Air is a poor conductor of heat, so trapping air between two layers of glass helps to keep heat inside the room and reduces heat loss to the cold air outside.
15. How do rubber tyres help protect boats when they hit the dock?
Answer: Rubber tyres are strong and flexible. They squash and spring back, helping to absorb the impact so the boat and dock are less likely to be damaged.