AI-generated practice question — model-generated for extra practice, not a previous-year CBSE board question.
When a base dissolves in water, it produces hydroxide ions, OH⁻(aq), in solution. The formation of OH⁻(aq) ions is responsible for the basic nature of a substance.
The examiner expects you to name OH⁻ (hydroxide) ions specifically. The source passage directly states: "Formation of OH⁻(aq) ions in solution is responsible for the basic nature of a substance." Writing the ion with its aqueous notation [OH⁻(aq)] shows precision and earns full marks.
Source: Chapter 2, What you have learnt (summary points)