New
New
Year 5

Rusting: an irreversible change

I can describe rusting as an irreversible change, where a new material is formed.

New
New
Year 5

Rusting: an irreversible change

I can describe rusting as an irreversible change, where a new material is formed.

Lesson details

Key learning points

  1. Rust is reddish brown in colour and has a rough texture.
  2. Rust is a new material that is formed when iron or steel is exposed to oxygen in the air and water.
  3. Rusting is an irreversible change whereby the original material cannot easily be recovered.
  4. Rusting materials can be looked at closely as they change over time, using observation skills.

Common misconception

Rusting happens immediately when the correct conditions are present and it only happens in water.

Teaching slides explain that rusting is not instant and that moisture from the air provides enough water for the process to take place.

Keywords

  • Rust - Rust is a reddish brown material which forms when iron or steel reacts with water and oxygen from the air.

  • Metal - A metal is a type of material.

  • Irreversible change - If a change is irreversible, it cannot be undone or changed back to its original state.

  • Observe - To observe is to look very closely and use other senses too.

Encourage pupils to recognise that the water in the air is enough to provide the water needed for rusting and that items do not need to be submerged or partly in water to rust.
Teacher tip

Equipment

Steel wool pads and bowls or saucers. Using a transparent centimetre square grid is optional.

Content guidance

  • Risk assessment required - equipment

Supervision

Adult supervision required

Licence

This content is © Oak National Academy Limited (2024), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).

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6 Questions

Q1.
What is a reversible change?
Correct answer: A change which can be undone or changed back to its original state.
A change which cannot be undone or changed back to its original state.
Q2.
Evaporation happens faster when the temperature is ...
An image in a quiz
Correct answer: warmer.
cooler.
Q3.
Match the reverse process of each change of state.
An image in a quiz
Correct Answer:melting,freezing

freezing

Correct Answer:condensation,evaporation

evaporation

Q4.
At temperatures between 0°C and 100°C, water is in state.
Correct Answer: liquid
Q5.
Which gas from the air is used during burning?
An image in a quiz
carbon dioxide
Correct answer: oxygen
air
Q6.
Match the process to the change of state.
Correct Answer:evaporation,when a liquid changes to a gas

when a liquid changes to a gas

Correct Answer:melting,when a solid changes to a liquid

when a solid changes to a liquid

Correct Answer:freezing,when a liquid changes to a solid

when a liquid changes to a solid

Correct Answer:condensation,when a gas changes to a liquid

when a gas changes to a liquid

6 Questions

Q1.
forms when iron is exposed to water and oxygen and is reddish brown in colour.
Correct Answer: Rust
Q2.
Which skills are needed to monitor changes in materials as they rust?
An image in a quiz
predicting
drawing
Correct answer: observation
modelling
concluding
Q3.
The changes observed in rusting materials ...
Correct answer: are often very slow.
are instant.
happen very quickly.
Q4.
What texture is rust?
An image in a quiz
smooth
Correct answer: rough
squishy
soft
Q5.
Which of these are needed for rust to form?
An image in a quiz
Correct answer: iron or steel
aluminium
Correct answer: oxygen
Correct answer: water
carbon dioxide
Q6.
Rusting is an change because it cannot be undone or changed back.
Correct Answer: irreversible

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