Write balanced chemical equations for the following reactions :
(i) When copper is heated in air.
(ii) When aluminium is heated in air.
(iii) Aluminium oxide reacts with Sodium hydroxide.

Explanation

To write balanced chemical equations for the given reactions, we will follow a systematic approach. Let's break down each reaction step by step.

### (i) When copper is heated in air:

1. **Identify the reactants**: Copper (Cu) and oxygen (O2) from the air.
2. **Write the unbalanced equation**:
\[
\text{Cu} + \text{O}_2 \rightarrow \text{CuO}
...