(a) Rusting of an

(a) Rusting of an article made up of iron is called corrosion and it is a chemical change.

Corrosion is a chemical change because in such change chemical properties or composition of the original substance changes resulting in the formation of at least one new substance.

For example the Formation of rust

The chemical reaction showing rusting of iron is shown below.

4Fe + 2O₂ → 2Fe₂O₃.xH₂O

(Hydrated iron oxide or rust)

(b) (i) The solute is the component that gets dissolved in a solvent to form a solution. It is present in a smaller amount when compared to the solvent.

(ii) The solvent is the component that dissolves a solute to form a solution. The solvent is present in a larger amount when compared to the solute.