What is the nature of metal oxides?

Explanation

### Step-by-Step Solution:

1. **Definition of Metal Oxides**: Metal oxides are compounds formed when metals react with oxygen. They typically consist of a metal ion and oxide ion (O²⁻).

2. **Example of a Metal Oxide**: Consider sodium oxide (Na₂O). When sodium oxide reacts with water, it forms sodium hydroxide (NaOH).

3. **Formation of a Base**: Sodium hydroxide (NaOH) is a well-known base. It can be defined as a substance that can donate hydroxide ions (OH⁻) when dissolved in water.

...