1. Rusting What is rust? Can you give examples of things that rust?
What do you think causes rust to form on objects?

3. How could we set up on experiment to investigate what causes rust to form?
Think about what iron has to come into contact with for rust to form on it!

4. Lesson Starter Describe how rust forms?
What may speed up the process of rusting?
What type of metal is protected against rust?
Why is rust a problem for people who use machinery?
How could you prevent rust from forming?

5. Rust Investigation

6. Iron and steel rust when they come into contact with water and oxygen.
They rust faster in salty water or acid rain.
Aluminium, on the other hand, does not corrode easily, because its surface is protected by a layer of aluminium oxide.

8. Lesson Starter
Name the chemical used to test for the presence of rust?
What is the colour change which takes place if rust is present?

9. Testing for the presence of Rust
FERROXYL INDICATOR is used to test for the presence of rust.
If rust is present it will turn from a yellow colour to a blue colour.

10. Here is the word equation for the reaction:
Rusting is an oxidation reaction. The iron reacts with water and oxygen to form hydrated iron (III) oxide, which we see as rust.
Here is the word equation for the reaction:
iron + water + oxygen → hydrated iron (III) oxide