Properties and uses of materials
By the end of this chapter you will be able to
- Compare and group materials by whether they are see-through, and by how hard they are
- Explain which materials conduct electricity, and use a circuit test to sort them
- Explain which materials conduct heat, and use a spoon test to compare them
- Say which materials are pulled by a magnet, and group materials by that property
- Give reasons, from evidence, for choosing a material for a particular use
You should already know
- Materials and their simple properties, such as hard, soft, shiny and see-through (Year 1 and Year 3 Science)
- Fair tests, and changing only one thing at a time (Year 5 Science, Chapter 1)
Where this leads
- Solutions and separating mixtures, where solubility is used (Year 5 Science, Chapter 6)
- Reversible and irreversible changes (Year 5 Science, Chapter 7)
National Curriculum for England, Key Stage 2 science, Year 5. Content: M1 compare and group together everyday materials on the basis of their properties: hardness, solubility, transparency, conductivity (electrical and thermal), response to magnets, M2 give reasons, based on evidence from comparative and fair tests, for the particular uses of everyday materials, including metals, wood and plastic.
Exercise P Do you remember?
Method. Think about a window you can see through.
- Think about the window. A window is often made of clear glass.clear glass
- Name the material. The material is glass.glass
- Write the answer. glass
Check. Glass lets light through. ✓
Method. Think about a bottle you can hold.
- Think about the bottle. A drinks bottle is often made of plastic.plastic
- Name the material. The material is plastic.plastic
- Write the answer. plastic
Check. Plastic is light and does not break easily. ✓
Method. Think about a clear window.
- Think about glass. You can see through a clear window.see through
- Decide. So the answer is yes.yes
- Write the answer. yes
Check. Some materials are see-through, and some are not. ✓
Method. Think about which material magnets attract.
- Think about magnets. A magnet pulls iron towards it.pulls iron
- Choose the material. So the answer is iron.iron
- Write the answer. iron
Check. Wood is not pulled by a magnet. ✓
Method. Think about the word for things a magnet pulls.
- Think about the word. A material that a magnet pulls towards it is called magnetic.pulls towards it
- Name it. The word is magnetic.magnetic
- Write the answer. magnetic
Check. Magnetic materials include iron and steel. ✓
Hardness and transparency
A property is a feature of a material that we can describe or measure, such as how hard it is or whether light can pass through it.
Hardness can be tested by scratching: a harder material makes fewer scratches on a softer test board. Transparent materials let you see clearly through them. Translucent materials let light through, but you cannot see clearly through them. Opaque materials do not let light through at all.
| Material | See-through? | Conducts electricity? | Conducts heat? | Pulled by a magnet? |
|---|---|---|---|---|
| iron nail | no | yes | yes | yes |
| aluminium foil | no | yes | yes | no |
| copper wire | no | yes | yes | no |
| clear glass | yes | no | no | no |
| clear plastic bottle | yes | no | no | no |
| wooden block | no | no | no | no |
| rubber band | no | no | no | no |
| Material | Number of scratches on the test board |
|---|---|
| clear glass | 0 |
| wooden block | 3 |
| iron nail | 2 |
Key ideas
- A property is a feature of a material that can be described or measured.
- A transparent material lets you see clearly through it.
- An opaque material does not let light through.
- A harder material makes fewer scratches than a softer one, in a fair scratch test.
Method. Read the see-through column.
- Read the row for each material. The clear glass row says yes, and the wooden block row says no.yes and no
- Choose the see-through one. So the see-through material is clear glass.clear glass
- Write the answer. clear glass
Check. You can see through clear glass. ✓
Method. Read the scratch table.
- Read the counts. The wooden block has 3 scratches, the iron nail 2, and the clear glass 0.3, 2, 0
- Choose the largest. The most scratches were made by the wooden block.wooden block
- Write the answer. wooden block
Check. The wooden block was the softest of the three in this test. ✓
Method. Read the scratch table.
- Find the zero. The clear glass row has 0 scratches.0
- Name the material. So the material with no scratches is clear glass.clear glass
- Write the answer. clear glass
Check. The glass did not mark the board in this test. ✓
Watch out
Watch out: a material that is hard to scratch is not always the same as one that is see-through. A property is tested separately, so look at each column on its own.
Try it (with your teacher). Take three small pieces of different materials (for example a plastic lid, a piece of card and a coin). With your teacher, gently scratch a soft board with each material, using the same pressure every time. Count the scratches. Then hold each material up to a window and say whether you can see through it.
Exam tip
Grown-up tip. Ask: “Which material is see-through? Which made the fewest scratches?” Let your child keep the test the same each time.
Exercise 5A Hardness and transparency
Method. Read the see-through column.
- Read the rows. The clear plastic bottle row says yes, and the copper wire row says no.yes and no
- Choose the see-through one. So the see-through material is the clear plastic bottle.clear plastic bottle
- Write the answer. clear plastic bottle
Check. Clear plastic lets you see through it. ✓
Method. Read the see-through column.
- Read the rows. The wooden block row says no, so you cannot see through it.no
- Choose the opaque one. So the opaque material is the wooden block.wooden block
- Write the answer. wooden block
Check. Clear glass is transparent, so it is not opaque. ✓
Method. Count the rows that say yes in the see-through column.
- Read the column. The rows that say yes are clear glass and clear plastic bottle.two yes rows
- Count them. So there are two see-through materials.2
- Write the answer. 2
Check. The other five materials are not see-through. ✓
Method. Read the scratch table.
- Read the table. The iron nail row shows 2 scratches.2
- Write the number. So the iron nail made 2 scratches.2
- Write the answer. 2
Check. The wooden block made 3 scratches. ✓
Method. Read the scratch table.
- Read the counts. The counts are 0 for clear glass, 3 for the wooden block and 2 for the iron nail.0, 3, 2
- Choose the answer. Clear glass made none, so the fewest scratches but some is the iron nail.iron nail
- Write the answer. iron nail
Check. Clear glass made no scratches at all. ✓
Method. Add the three counts.
- Add the counts. The counts are 0, 3 and 2.0 + 3 + 2
- Find the total. The total is 5 scratches.5
- Write the answer. 5
Check. Check: 3 + 2 = 5. ✓
Method. Read the see-through column.
- Read the column. The rows that say no are the iron nail, aluminium foil, copper wire, wooden block and rubber band.five rows
- Name two. Two of the materials that are not see-through are the wooden block and the rubber band.wooden block and rubber band
- Write the answer. wooden block and rubber band
Check. Any two of the five opaque materials are a correct answer. ✓
Method. Read the key ideas in section 5.1.
- Read the key idea. A transparent material lets you see clearly through it.see clearly through
- Fill the gap. So the missing word is transparent.transparent
- Write the answer. transparent
Check. Opaque materials let no light through. ✓
Method. Read the key ideas in section 5.1.
- Read the key idea. An opaque material does not let light through.does not let light through
- Fill the gap. So the missing word is opaque.opaque
- Write the answer. opaque
Check. Wood and metal are opaque. ✓
Method. Think about what makes a scratch test fair.
- Think about the test. Only the material should change between tests.only the material
- Write one thing. The pressure, the board and the number of strokes must stay the same.stay the same
- Write the answer. Accept any one of: the same pressure, the same test board, the same number of strokes.
Check. A fair test changes only one thing. ✓
Method. Think about the scratch test.
- Think about the material. A harder material resists being marked.resists being marked
- Write the reason. So it makes fewer scratches on the test board.fewer scratches
- Write the answer. Accept any sentence that says a harder material is less easily marked, so it makes fewer scratches on the board.
Check. Hardness is judged by the scratches in a fair test. ✓
Electrical conductivity
Electricity passes through some materials but not others. A material that lets electricity pass through it is a conductor. A material that does not let electricity pass through it is an insulator.
In a circuit with a bulb, the bulb lights when a conductor completes the loop. Metals, such as iron, aluminium and copper, are good conductors. Plastic, wood, glass and rubber are insulators.
The test results for the materials in section 5.1 are in the table. The bulb lit when a material conducted electricity.
| Material | See-through? | Conducts electricity? | Conducts heat? | Pulled by a magnet? |
|---|---|---|---|---|
| iron nail | no | yes | yes | yes |
| aluminium foil | no | yes | yes | no |
| copper wire | no | yes | yes | no |
| clear glass | yes | no | no | no |
| clear plastic bottle | yes | no | no | no |
| wooden block | no | no | no | no |
| rubber band | no | no | no | no |
Key ideas
- A conductor lets electricity pass through it, so the bulb lights.
- An insulator does not let electricity pass through it, so the bulb stays off.
- Metals such as iron, aluminium and copper are conductors.
- Plastic, wood, glass and rubber are insulators.
Method. Read the electricity column.
- Read the rows. The copper wire row says yes, and the wooden block row says no.yes and no
- Choose the conductor. So the material that conducts electricity is copper wire.copper wire
- Write the answer. copper wire
Check. Copper is a metal, and metals conduct electricity. ✓
Method. Read the electricity column for clear glass.
- Read the row. The clear glass row says no for conducts electricity.no
- Name the kind. A material that does not conduct electricity is an insulator.insulator
- Write the answer. insulator
Check. Glass is an insulator. ✓
Method. Count the yes rows in the electricity column.
- Read the column. The yes rows are the iron nail, aluminium foil and copper wire.three yes rows
- Count them. So three materials conduct electricity.3
- Write the answer. 3
Check. The other four materials are insulators. ✓
Watch out
Watch out: a bulb that stays off does not always mean that a material is safe. Only test with the low-voltage battery pack your teacher gives you, and never connect a circuit to the mains electricity.
Try it (with your teacher). Use a low-voltage battery pack, a bulb in a holder and some crocodile clips, all set up by your teacher. Put a metal paper clip, a plastic ruler, a rubber band and a wooden lolly stick in the gap, one at a time. Record whether the bulb lights each time in a table.
Exam tip
Grown-up tip. Ask: “Which materials let the electricity pass? Which did not? What do they have in common?” Let your child sort the materials into two groups.
Exercise 5B Electrical conductivity
Method. Read the electricity column.
- Read the column. The iron nail row says yes for conducts electricity.yes
- Name one. So the iron nail is one material that conducts electricity.iron nail
- Write the answer. iron nail
Check. Accept any of: iron nail, aluminium foil, copper wire. ✓
Method. Read the row for aluminium foil.
- Read the row. The aluminium foil row says yes for conducts electricity.yes
- Name the kind. A material that conducts electricity is a conductor.conductor
- Write the answer. conductor
Check. Aluminium is a metal. ✓
Method. Read the row for the clear plastic bottle.
- Read the row. The clear plastic bottle row says no for conducts electricity.no
- Name the kind. A material that does not conduct electricity is an insulator.insulator
- Write the answer. insulator
Check. Plastic is used to cover electric wires. ✓
Method. Read the key ideas in section 5.2.
- Read the key idea. A conductor lets electricity pass through it.lets electricity pass
- Fill the gap. So the missing word is conductor.conductor
- Write the answer. conductor
Check. An insulator does not let electricity pass. ✓
Method. Read the key ideas in section 5.2.
- Read the description. The bulb lights when a conductor completes the loop.lights
- Name the result. So the answer is lights.lights
- Write the answer. lights
Check. Accept lights, or lights up. ✓
Method. Count the rows that say no for conducts electricity.
- Read the column. The no rows are clear glass, clear plastic bottle, wooden block and rubber band.four no rows
- Count them. So there are four insulators.4
- Write the answer. 4
Check. Seven materials, three conductors, and four insulators. ✓
Method. Read the rows for the conductors.
- Read the rows. The conductors are the iron nail, the aluminium foil and the copper wire.three conductors
- Name the wire. The wire is the copper wire.copper wire
- Write the answer. copper wire
Check. Copper wire is used to carry electricity. ✓
Method. Read the labels in the circuit.
- Read the labels. The labels are cell, bulb, switch and the gap for the material.switch
- Name the part. The part that is turned on or off is the switch.switch
- Write the answer. switch
Check. A switch opens and closes the loop. ✓
Method. Read the labels in the circuit.
- Read the labels. The labels are cell, bulb, switch and the gap for the material.cell
- Name the part. The part that gives the electricity is the cell.cell
- Write the answer. cell
Check. The cell is the source of electricity. ✓
Method. Read the wooden block row.
- Read the row. The wooden block row says no for conducts electricity.no
- Name the group. So a wooden block is an insulator.insulator
- Write the answer. insulator
Check. Wood does not conduct electricity. ✓
Method. Think about each material in the circuit.
- Think about the metal. Metals conduct electricity, so the bulb lights.bulb lights
- Think about the plastic. Plastic is an insulator, so the bulb stays off.stays off
- Write the answer. Accept any sentence that says the metal paper clip conducts electricity so the bulb lights, but the plastic ruler is an insulator so the bulb stays off.
Check. Conductors complete the circuit, and insulators do not. ✓
Thermal conductivity
A material that lets heat pass through it easily is a good thermal conductor. Metals are good conductors of heat. Wood and plastic are poor conductors, so they are used for handles.
In a fair test, three spoons are put into warm water with a drop of butter on each bowl. The spoon that conducts heat best moves the heat up to the butter fastest, so the butter melts and slides off sooner.
The results of a class test are in the table. Each spoon was put in warm water in the same way, with the same amount of butter.
| Spoon | Seconds for the butter to melt and slide off |
|---|---|
| metal spoon | 40 |
| plastic spoon | 150 |
| wooden spoon | 180 |
Key ideas
- A good conductor of heat moves heat quickly through the material.
- In the spoon test, the metal spoon was fastest, because metals conduct heat well.
- Wood and plastic are poor conductors of heat, so they make good handles.
- A fair test keeps the water, the butter and the spoons the same.
Method. Find the shortest time.
- Read the times. The metal spoon took 40 seconds, the plastic spoon 150 seconds, and the wooden spoon 180 seconds.40, 150, 180
- Choose the shortest. The shortest time is 40 seconds, for the metal spoon.metal spoon
- Write the answer. metal spoon
Check. The metal spoon conducts heat best. ✓
Method. Subtract the metal spoon time from the wooden spoon time.
- Read the two times. The wooden spoon took 180 seconds, and the metal spoon took 40 seconds.180 and 40
- Subtract. The difference is 180 minus 40, which is 140.180 - 40 = 140
- Write the answer. 140
Check. Check: 40 + 140 = 180. ✓
Watch out. Subtract the smaller time from the larger time.
Method. Read the results and the key ideas.
- Read the key idea. Wood and plastic are poor conductors of heat.poor conductors
- Choose the answer. So wood is a poor conductor of heat.poor conductor
- Write the answer. poor conductor
Check. The wooden spoon was the slowest in the test. ✓
Watch out
Watch out: a metal spoon feels hot because it conducts heat to your hand. The metal did not make the heat. Only fair tests show which material conducts heat best.
Try it (with your teacher). Use warm tap water (not hot), a metal spoon, a plastic spoon and a wooden spoon. Put a small piece of butter on the bowl of each spoon, and stand them in warm water in the same way. Time how long the butter takes to melt and slide off. Keep your hands out of the hot water, and be careful with the spoons.
Exam tip
Grown-up tip. Ask: “Which spoon was fastest? Why do you think the wooden handle feels cool?” Let your child keep the test fair by changing only the spoon.
Exercise 5C Thermal conductivity
Method. Find the shortest time in the table.
- Read the times. The metal spoon took 40 seconds, the shortest time.40 seconds
- Name the spoon. So the metal spoon melted the butter fastest.metal spoon
- Write the answer. metal spoon
Check. Metals conduct heat well. ✓
Method. Find the longest time in the table.
- Read the times. The wooden spoon took 180 seconds, the longest time.180 seconds
- Name the spoon. So the wooden spoon took the longest.wooden spoon
- Write the answer. wooden spoon
Check. Wood is a poor conductor of heat. ✓
Method. Read the row for the plastic spoon.
- Read the row. The plastic spoon row shows 150 seconds.150
- Write the number. So the plastic spoon took 150 seconds.150
- Write the answer. 150
Check. The plastic spoon took longer than the metal spoon. ✓
Method. Subtract the metal time from the plastic time.
- Read the times. The plastic spoon took 150 seconds, and the metal spoon took 40 seconds.150 and 40
- Subtract. The difference is 150 minus 40, which is 110.150 - 40 = 110
- Write the answer. 110
Check. Check: 40 + 110 = 150. ✓
Method. Read the key ideas in section 5.3.
- Read the key idea. A good conductor of heat moves heat quickly through the material.moves heat quickly
- Fill the gap. So the missing word is quickly.quickly
- Write the answer. quickly
Check. Metals are good conductors of heat. ✓
Method. Read the key ideas in section 5.3.
- Read the key idea. Wood and plastic are poor conductors of heat.poor conductors
- Give the answer. So they are poor conductors.poor conductors
- Write the answer. poor conductors
Check. This is why wooden and plastic handles stay cool. ✓
Method. Think about which material conducts heat poorly.
- Think about the handle. A wooden handle is a poor conductor, so it stays cool.stays cool
- Choose the spoon. So a wooden spoon is the better choice.wooden
- Write the answer. wooden
Check. The wooden handle is cooler to hold. ✓
Method. Find the longest time.
- Find the longest. The longest time is 180 seconds, for the wooden spoon.180
- Write the number. So the slowest spoon took 180 seconds.180
- Write the answer. 180
Check. The wooden spoon was the slowest. ✓
Method. Think about what makes the test fair.
- Think about the test. Only the type of spoon should change.type of spoon
- Write one thing. The water temperature, the butter and the bowl size must stay the same.stay the same
- Write the answer. Accept any one of: the same amount of water, the same amount of butter, the same size of spoon bowl.
Check. Changing only the spoon keeps the test fair. ✓
Method. Think about how heat moves through each spoon.
- Think about the metal. Metal conducts heat well, so heat moves up to the handle.conducts heat well
- Think about the wood. Wood is a poor conductor, so the handle stays cool.poor conductor
- Write the answer. Accept any sentence that says metal conducts heat well to your hand, but wood is a poor conductor, so the wooden handle stays cool.
Check. Heat moves through metal much more quickly. ✓
Materials and magnets
A magnet pulls some materials towards it. These are magnetic materials. Iron and steel are magnetic. Most other materials, including copper, aluminium, wood, plastic, glass and rubber, are not magnetic, and a magnet does not pull them.
A magnet can pull a magnetic material towards it across a small gap. It does not need to be touching it.
The table shows which materials are pulled by a magnet in a fair test.
| Material | See-through? | Conducts electricity? | Conducts heat? | Pulled by a magnet? |
|---|---|---|---|---|
| iron nail | no | yes | yes | yes |
| aluminium foil | no | yes | yes | no |
| copper wire | no | yes | yes | no |
| clear glass | yes | no | no | no |
| clear plastic bottle | yes | no | no | no |
| wooden block | no | no | no | no |
| rubber band | no | no | no | no |
Key ideas
- Iron and steel are magnetic materials.
- A magnet pulls a magnetic material towards it.
- Copper, aluminium, wood, plastic, glass and rubber are not pulled by a magnet.
- A magnet can pull a magnetic material across a small gap.
Method. Read the magnet column.
- Read the rows. The iron nail row says yes, and the aluminium foil row says no.yes and no
- Choose the magnetic one. So the material pulled by a magnet is the iron nail.iron nail
- Write the answer. iron nail
Check. Iron is a magnetic material. ✓
Method. Count the yes rows in the magnet column.
- Read the column. Only the iron nail row says yes.one yes row
- Count them. So one material is pulled by a magnet.1
- Write the answer. 1
Check. Only iron is pulled among these seven materials. ✓
Method. Read the magnet column for copper wire.
- Read the row. The copper wire row says no for pulled by a magnet.no
- Decide. So copper wire is not magnetic.no
- Write the answer. no
Check. Copper is a metal, but it is not magnetic. ✓
Watch out
Watch out: not all metals are magnetic. Copper and aluminium are metals, but a magnet does not pull them.
Try it (with your teacher). With your teacher, put a bar magnet near a set of small objects: an iron nail, a copper coin, an aluminium foil ball, a plastic bead and a rubber band. Record which objects the magnet pulls. Keep magnets away from phones and bank cards.
Exam tip
Grown-up tip. Ask: “Which objects did the magnet pull? Which were not pulled? Are they all metal?” Let your child sort the objects into two groups.
Exercise 5D Materials and magnets
Method. Read the magnet column.
- Read the column. The iron nail row says yes for pulled by a magnet.yes
- Name it. So the magnetic material is the iron nail.iron nail
- Write the answer. iron nail
Check. Iron is magnetic. ✓
Method. Read the row for aluminium foil.
- Read the row. The aluminium foil row says no for pulled by a magnet.no
- Decide. So aluminium foil is not magnetic.no
- Write the answer. no
Check. Aluminium is a metal, but it is not magnetic. ✓
Method. Read the row for the wooden block.
- Read the row. The wooden block row says no.no
- Decide. So a wooden block is not magnetic.no
- Write the answer. no
Check. Wood is not pulled by a magnet. ✓
Method. Read the key ideas in section 5.4.
- Read the key idea. A magnet pulls a magnetic material towards it.magnetic material
- Fill the gap. So the missing word is magnetic.magnetic
- Write the answer. magnetic
Check. Magnetic materials include iron and steel. ✓
Method. Read the key ideas.
- Read the key idea. Iron and steel are magnetic materials.iron and steel
- Name one. One of these is iron.iron
- Write the answer. iron
Check. Accept iron or steel. ✓
Method. Count the rows that say no in the magnet column.
- Read the column. Only the iron nail says yes, so the other six say no.six no rows
- Count them. So six materials are not pulled by a magnet.6
- Write the answer. 6
Check. Seven materials, one magnetic, so six are not. ✓
Method. Read the row for copper wire.
- Read the row. The copper wire row says no for pulled by a magnet.no
- Decide. So copper is not magnetic.no
- Write the answer. no
Check. Copper conducts electricity, but it is not magnetic. ✓
Method. Look at the metals in the table.
- Look at the metals. The aluminium foil and copper wire are metals, but a magnet does not pull them.not pulled
- Decide. So Tom is not right.no
- Write the answer. no
Check. Only some metals, such as iron and steel, are magnetic. ✓
Method. Think about magnetic materials.
- Think about steel. Steel is a magnetic material.steel is magnetic
- Make the prediction. So a magnet will pull a steel paperclip.yes
- Write the answer. yes
Check. Test your prediction with your teacher. ✓
Method. Think about the two materials.
- Think about the nail. Iron is magnetic, so the magnet pulls it, even across a gap.magnetic
- Think about the wire. Copper is not magnetic, so the magnet cannot pull it.not magnetic
- Write the answer. Accept any sentence that says iron is a magnetic material, so the magnet pulls it, but copper is not magnetic, so it is not pulled.
Check. Only magnetic materials are pulled by a magnet. ✓
Choosing materials for a use
We choose a material for a job by matching its properties to what the job needs. The evidence from our fair tests helps us to decide.
- A saucepan base needs to conduct heat, so the food heats up quickly. Metal is a good choice.
- A saucepan handle should stay cool and not conduct heat, so the cook can hold it safely. Plastic or wood is a good choice.
- A window needs to be transparent, so that light comes in and people can see out. Glass is a good choice.
- A wooden table needs to be strong and opaque, so it does not let light through, and it does not bend easily.
Key ideas
- Choose a material by matching its properties to the job.
- A metal base conducts heat, so the food heats quickly.
- A plastic or wooden handle does not conduct heat well, so it stays cool.
- Glass is transparent, so it is used for windows. Wood is opaque, so it is used for tables.
Method. Think about what the base needs to do.
- Think about the base. The base must conduct heat, so the food heats up quickly.conduct heat
- Choose the part. So the base should be the part that conducts heat.metal base
- Write the answer. metal base
Check. Metal conducts heat well. ✓
Method. Think about the handle.
- Think about the handle. A plastic handle does not conduct heat, so it stays cool to hold.stays cool
- Write the reason. So the cook can hold the pan safely.stays cool
- Write the answer. it stays cool to hold
Check. The evidence from the spoon test shows plastic is a poor conductor of heat. ✓
Method. Think about what a window needs.
- Think about the window. A window needs to be transparent, so that light comes in.transparent
- Choose the material. Glass is transparent, but wood is opaque, so glass is the best choice.glass
- Write the answer. glass
Check. Clear glass was see-through in the test. ✓
Watch out
Watch out: a material is not chosen for one property alone. A saucepan base needs to conduct heat, but a handle must not. Think about the job as a whole.
Try it (with your teacher). Choose one object at home or school, such as a cup, a spoon or a bag. With a grown-up, list the properties it needs for its job. Then say which material it is made of, and give one reason, based on a property you have tested.
Exam tip
Grown-up tip. Ask: “What job does this object do? What does its material need to be good at?” Let your child use the evidence from the tests in this chapter.
Exercise 5E Choosing materials for a use
Method. Read the bullet points in section 5.5.
- Read the bullets. A saucepan base needs to conduct heat, so the food heats up quickly.conduct heat
- Name the part. So the part is the metal base.metal base
- Write the answer. metal base
Check. Metal is a good conductor of heat. ✓
Method. Read the bullet points in section 5.5.
- Read the bullets. A handle should stay cool and not conduct heat.stay cool
- Name the part. So the part is the plastic handle.plastic handle
- Write the answer. plastic handle
Check. Plastic is a poor conductor of heat. ✓
Method. Read the bullet points in section 5.5.
- Read the bullets. A window needs to be transparent.transparent
- Name the material. Glass is transparent, so the answer is glass.glass
- Write the answer. glass
Check. Clear glass is see-through. ✓
Method. Read the bullet points in section 5.5.
- Read the bullets. A table needs to be strong and opaque.strong and opaque
- Name the material. So the material is wood.wood
- Write the answer. wood
Check. Wood is opaque, so light does not pass through it. ✓
Method. Look at the test results in section 5.1.
- Look at the test. Clear glass is see-through, so it is transparent.see-through
- Choose the property. So the property is transparent.transparent
- Write the answer. transparent
Check. Glass is not magnetic. ✓
Method. Find the spoon with the shortest time.
- Find the shortest time. The metal spoon took the shortest time, 40 seconds.40 seconds
- Name the material. So the material that conducts heat fastest is metal.metal
- Write the answer. metal
Check. The metal spoon melted the butter first. ✓
Method. Think about which material is magnetic.
- Think about magnets. Iron is magnetic, and wood is not.iron is magnetic
- Choose the material. So iron is the material that the magnet can pull.iron
- Write the answer. iron
Check. The magnet can only pull a magnetic material. ✓
Method. Think about the job of the cup.
- Think about the job. A cup for a hot drink should stay cool to hold, so it should not conduct heat well.stay cool
- Choose the material. Plastic is a poor conductor of heat, so plastic is the better choice.plastic
- Write the answer. plastic
Check. Accept plastic, or any poor conductor of heat. ✓
Method. Think about the properties of wood.
- Think about the wood. Wood is a poor conductor of heat.poor conductor
- Write the reason. So the handle stays cool when the spoon is in hot food.stays cool
- Write the answer. Accept any sentence that says wood is a poor conductor of heat, so the handle stays cool to hold.
Check. The spoon test showed that wood is a poor conductor. ✓
Method. Think about the conductivity of each material.
- Think about the copper. Copper conducts electricity, so the circuit works.conducts electricity
- Think about the plastic. Plastic is an insulator, so it does not carry the electricity.insulator
- Write the answer. Accept any sentence that says copper conducts electricity, so the circuit works, while plastic is an insulator, so it does not carry electricity.
Check. The circuit test showed which materials conduct. ✓
Chapter summary
| Skill | Method |
|---|---|
| Hardness and transparency | A harder material makes fewer scratches. Transparent materials let you see through them; opaque ones do not. |
| Electrical conductivity | Conductors, such as metals, let electricity pass through them. Insulators, such as plastic, wood and glass, do not. |
| Thermal conductivity | Metals conduct heat well. Wood and plastic are poor conductors, so they are used for handles. |
| Magnetic materials | Iron and steel are magnetic. Copper, aluminium, wood, plastic, glass and rubber are not pulled by a magnet. |
| Choosing materials | Match a material’s properties to the job, and use evidence from fair tests to justify the choice. |
Can you…?
- I can compare materials by hardness and transparency, using a fair test
- I can say which materials conduct electricity, and sort them into conductors and insulators
- I can use a spoon test to compare how well materials conduct heat
- I can say which materials are magnetic, and group materials by that property
- I can give reasons, from evidence, for choosing a material for a use
Key terms
- property
- a feature of a material that can be described or measured
- transparent
- a material that you can see clearly through
- opaque
- a material that does not let light through
- hardness
- how difficult a material is to scratch or mark
- conductor
- a material that lets electricity pass through it
- insulator
- a material that does not let electricity pass through it
- thermal conductor
- a material that lets heat pass through it easily
- magnetic material
- a material that a magnet pulls towards it, such as iron or steel
- fair test
- a test in which only one thing is changed, and everything else is kept the same
Exercise 5Z Check-up
| Material | See-through? | Conducts electricity? | Conducts heat? | Pulled by a magnet? |
|---|---|---|---|---|
| iron nail | no | yes | yes | yes |
| aluminium foil | no | yes | yes | no |
| copper wire | no | yes | yes | no |
| clear glass | yes | no | no | no |
| clear plastic bottle | yes | no | no | no |
| wooden block | no | no | no | no |
| rubber band | no | no | no | no |
Method. Read the see-through column.
- Read the rows. The clear glass row says yes, and the rubber band row says no.yes and no
- Choose the see-through one. So the see-through material is clear glass.clear glass
- Write the answer. clear glass
Check. Clear glass lets you see through it. ✓
| Material | See-through? | Conducts electricity? | Conducts heat? | Pulled by a magnet? |
|---|---|---|---|---|
| iron nail | no | yes | yes | yes |
| aluminium foil | no | yes | yes | no |
| copper wire | no | yes | yes | no |
| clear glass | yes | no | no | no |
| clear plastic bottle | yes | no | no | no |
| wooden block | no | no | no | no |
| rubber band | no | no | no | no |
Method. Read the electricity column.
- Read the rows. The aluminium foil row says yes for conducts electricity.yes
- Choose the conductor. So aluminium foil conducts electricity.aluminium foil
- Write the answer. aluminium foil
Check. Aluminium is a metal, so it conducts electricity. ✓
| Spoon | Seconds for the butter to melt and slide off |
|---|---|
| metal spoon | 40 |
| plastic spoon | 150 |
| wooden spoon | 180 |
Method. Find the shortest time.
- Find the shortest time. The metal spoon took 40 seconds.40 seconds
- Name the spoon. So the metal spoon was fastest.metal spoon
- Write the answer. metal spoon
Check. Metals conduct heat well. ✓
| Material | See-through? | Conducts electricity? | Conducts heat? | Pulled by a magnet? |
|---|---|---|---|---|
| iron nail | no | yes | yes | yes |
| aluminium foil | no | yes | yes | no |
| copper wire | no | yes | yes | no |
| clear glass | yes | no | no | no |
| clear plastic bottle | yes | no | no | no |
| wooden block | no | no | no | no |
| rubber band | no | no | no | no |
Method. Read the magnet column.
- Read the column. Only the iron nail row says yes.iron nail
- Name it. So the material pulled by a magnet is the iron nail.iron nail
- Write the answer. iron nail
Check. Iron is a magnetic material. ✓
| Material | See-through? | Conducts electricity? | Conducts heat? | Pulled by a magnet? |
|---|---|---|---|---|
| iron nail | no | yes | yes | yes |
| aluminium foil | no | yes | yes | no |
| copper wire | no | yes | yes | no |
| clear glass | yes | no | no | no |
| clear plastic bottle | yes | no | no | no |
| wooden block | no | no | no | no |
| rubber band | no | no | no | no |
Method. Read the row for the clear plastic bottle.
- Read the row. The clear plastic bottle row says no for conducts electricity.no
- Decide. So the answer is no.no
- Write the answer. no
Check. Plastic is an insulator. ✓
| Material | Number of scratches on the test board |
|---|---|
| clear glass | 0 |
| wooden block | 3 |
| iron nail | 2 |
Method. Read the scratch table.
- Read the table. The wooden block row shows 3 scratches.3
- Write the number. So the wooden block made 3 scratches.3
- Write the answer. 3
Check. The iron nail made 2 scratches. ✓
Method. Read the key ideas in section 5.1.
- Read the key idea. A transparent material lets you see clearly through it.see clearly through
- Fill the gap. So the missing word is transparent.transparent
- Write the answer. transparent
Check. Opaque materials let no light through. ✓
Method. Read the key ideas in section 5.2.
- Read the key idea. A conductor lets electricity pass through it.lets electricity pass
- Fill the gap. So the missing word is conductor.conductor
- Write the answer. conductor
Check. Insulators do not let electricity pass. ✓
Method. Read the labels in the picture.
- Read the labels. The plastic handle does not conduct heat.does not conduct heat
- Name the part. So the part is the plastic handle.plastic handle
- Write the answer. plastic handle
Check. The handle stays cool to hold. ✓
Method. Think about each part.
- Think about the base. The base is metal, so it conducts heat to the food.conducts heat
- Think about the handle. The handle is plastic, so it does not conduct heat and stays cool.stays cool
- Write the answer. Accept any sentence that says metal conducts heat so the food heats quickly, while plastic does not conduct heat so the handle stays cool.
Check. Each part is matched to its job. ✓
Total 20 marks. Allow about 20 minutes.
Exercise 5X Practice test questions
| Material | See-through? | Conducts electricity? | Conducts heat? | Pulled by a magnet? |
|---|---|---|---|---|
| iron nail | no | yes | yes | yes |
| aluminium foil | no | yes | yes | no |
| copper wire | no | yes | yes | no |
| clear glass | yes | no | no | no |
| clear plastic bottle | yes | no | no | no |
| wooden block | no | no | no | no |
| rubber band | no | no | no | no |
Method. Read the rows for glass.
- Read the rows. The clear glass row says yes for see-through.yes
- Name it. So the see-through glass is clear glass.clear glass
- Write the answer. clear glass
Check. Glass is used for windows because it is see-through. ✓
Method. Read the key ideas in section 5.4.
- Read the key idea. A magnet pulls a magnetic material towards it.magnetic
- Name it. The word is magnetic.magnetic
- Write the answer. magnetic
Check. Iron and steel are magnetic. ✓
Method. Read the key ideas in section 5.2.
- Read the key idea. A conductor lets electricity pass through it.lets electricity pass
- Name it. The word is conductor.conductor
- Write the answer. conductor
Check. Insulators do not let electricity pass through. ✓
| Spoon | Seconds for the butter to melt and slide off |
|---|---|
| metal spoon | 40 |
| plastic spoon | 150 |
| wooden spoon | 180 |
Method. Subtract the metal time from the plastic time.
- Read the times. The plastic spoon took 150 seconds, and the metal spoon took 40 seconds.150 and 40
- Subtract. The difference is 150 minus 40, which is 110.150 - 40 = 110
- Write the answer. 110
Check. Check: 40 + 110 = 150. ✓
| Material | Number of scratches on the test board |
|---|---|
| clear glass | 0 |
| wooden block | 3 |
| iron nail | 2 |
Method. Add the three counts.
- Add the counts. The counts are 0, 3 and 2.0 + 3 + 2
- Find the total. The total is 5 scratches.5
- Write the answer. 5
Check. Check: 3 + 2 = 5. ✓
| Material | See-through? | Conducts electricity? | Conducts heat? | Pulled by a magnet? |
|---|---|---|---|---|
| iron nail | no | yes | yes | yes |
| aluminium foil | no | yes | yes | no |
| copper wire | no | yes | yes | no |
| clear glass | yes | no | no | no |
| clear plastic bottle | yes | no | no | no |
| wooden block | no | no | no | no |
| rubber band | no | no | no | no |
Method. Read the magnet column.
- Read the column. The rows that say no for pulled by a magnet include aluminium foil and copper wire.no
- Name two. Two materials that a magnet does not pull are aluminium foil and copper wire.two names
- Write the answer. aluminium foil and copper wire
Check. Accept any two of: aluminium foil, copper wire, clear glass, clear plastic bottle, wooden block, rubber band. ✓
Method. Use the evidence from the spoon test.
- Read the evidence. The metal spoon melted the butter fastest.40 seconds
- Write the reason. So a metal base conducts heat into the food quickly.conducts heat
- Write the answer. Accept any sentence that says metal conducts heat well, as the metal spoon melted the butter fastest, so the food heats up quickly.
Check. The test is the evidence for the reason. ✓
| Material | See-through? | Conducts electricity? | Conducts heat? | Pulled by a magnet? |
|---|---|---|---|---|
| iron nail | no | yes | yes | yes |
| aluminium foil | no | yes | yes | no |
| copper wire | no | yes | yes | no |
| clear glass | yes | no | no | no |
| clear plastic bottle | yes | no | no | no |
| wooden block | no | no | no | no |
| rubber band | no | no | no | no |
Method. Read the copper wire row.
- Read the row. The copper wire row says no for pulled by a magnet.no
- Give the reason. So copper is not magnetic, even though it is a metal.not magnetic
- Write the answer. no. Accept any reason that says copper wire is not pulled by a magnet in the table, so it is not magnetic.
Check. Not all metals are magnetic. ✓
Method. Compare the properties.
- Think about the window. A window needs to be transparent, so light comes in.transparent
- Think about the table. A wooden table is opaque and strong, so it does not need to let light through.opaque
- Write the answer. Accept any sentence that says glass is transparent, so light comes in, while wood is opaque and a table needs to be strong.
Check. Each material is matched to its job. ✓
Method. Compare the properties.
- Think about the wood. The wooden block is tested for hardness and does not conduct electricity.does not conduct
- Give the reason. Hardness and conductivity are different properties, tested separately.different properties
- Write the answer. no. Accept any reason that says hardness and conductivity are different properties, so a hard material may not conduct electricity, such as wood.
Check. Each property must be tested on its own. ✓