Question

The articles made of silver metal become dark on prolonged exposure to air. This is due to the formation of a layer of its ______.

Options

• oxide

• hydride

• sulphide

• carbonate

Answer 1

The articles made of silver metal become dark on prolonged exposure to air. This is due to the formation of a layer of its sulphide.

Explanation:

Silver objects turn black over time because silver reacts with trace amounts of hydrogen sulphide (H₂S) gas present in the atmosphere. This chemical reaction forms a thin, dark layer of silver sulphide (Ag₂S) on the surface, a process commonly known as tarnishing. The other options are incorrect because silver does not readily react with atmospheric oxygen, hydrogen, or carbon dioxide to form stable oxides, hydrides, or carbonates at room temperature.