Question

An element combines with oxygen to form an oxide. The oxide dissolves in water. This aqueous solution changes blue litmus to red. Write:

The nature of element (metal or non metal).

Answer 1

When an element combines with Oxygen $\left({\mathrm{O}}_2\right)$, then it forms an Oxide $\left({\mathrm{O}}^{2-}\right)$. This Oxide $\left({\mathrm{O}}^{2-}\right)$ in water changes blue litmus to red. Litmus paper is majorly used for testing whether an aqueous solution is acidic, basic, or alkaline in nature.

1. When the solution changes the color of litmus paper from blue to red, then the solution is acidic.
2. When the solution changes the color of litmus paper from red to blue, then the solution is basic.

Since the non-metallic oxides are acidic in nature. Hence, the nature of the element is non-metal.