Question

Which of the following substances in the gaseous state should be called a vapour ? Why?
i)helium ii)nitrogen iii)carbon dioxide iv)sulphur

Answer 1

Sulphur in gaseous state is called a vapour.

Sulphur exists as a solid at room temperature while all other molecules (helium, nitrogen and carbon dioxide) exist in gaseous state.
The gaseous phase of substances that exist in solid or liquid state at room temperature are called as vapour.