AI-generated practice question — model-generated for extra practice, not a previous-year CBSE board question.
Metallic oxides are called basic oxides because they react with water to form bases (alkalies) and react with acids to form salt and water.
For example:
$$\text{CaO} + \text{H}_2\text{O} \rightarrow \text{Ca(OH)}_2 \text{ (a base)}$$
$$\text{CaO} + \text{H}_2\text{SO}_4 \rightarrow \text{CaSO}_4 + \text{H}_2\text{O}$$
Thus, metallic oxides show basic nature, hence they are called basic oxides.
Source: Chapter 3, Section 3.1 (Activity 3.8)
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Examiners expect you to state the reason clearly — metallic oxides are basic because they dissolve in water to give bases and/or neutralise acids. Supporting with at least one chemical equation earns the second mark. Mentioning the exception (amphoteric oxides like Al₂O₃ and ZnO) is a bonus but not required for 2 marks.