Describe the role played in the extraction of aluminium by each of the substances listed.

1. Cryolite
2. Sodium hydroxide
3. Graphite

Give scientific reasons for: Zinc oxide can be reduced to zinc by using carbon monoxide, but aluminium oxide cannot be reduced by a reducing agent.

A metal 'X' has a valency 2 and a non-metal 'Y' has a valency 3. Write an equation to show how 'Y' forms an ion.

Select which is not an alloy of copper :

1. Brass
2. Bronze
3. Solder
4. Duralumin.