Answer to Question #58488 in Molecular Physics | Thermodynamics for sultan

Question

when can a gas be describe as a vapour?

Answer 1

In physics a vapour is a substance in the gas phase at a temperature lower than its critical point, which means that the vapor can be condensed to a liquid by increasing the pressure on it without reducing the temperature.
Vapour refers to a gas phase at a temperature where the same substance can also exist in the liquid or solid state, below the critical temperature of the substance.