Sophie Ryder is a sculptor who makes large metal animals from steel. Most of her work is placed outside so to stop it from rusting it is galvanised - the sculptures are dipped in zinc. Zinc is a metal but at temperatures of 450 degrees Celsius it becomes a liquid. Zinc is used because it does not rust like iron or steel. In the zinc bath, a chemical reaction makes the zinc stick to the metal forming a protective coating. If the galvanising is not damaged it should last up to a hundred years.

First broadcast:
11 October 2007

Rusting is an example of a chemical change and could be used to lead a discussion on other instances of irreversible and reversible changes. When learning about the melting points, this clip could be used to introduce research and experimentation on the melting points of different materials. Pupils may also use this clip to instigate discussions on properties of materials.