What is one example how gas turns into liquid

A rain cloud. When water evaporates, it's a gas and makes up clouds. Then when the cloud rains, the gas turns back into a liquid.

If the water vapor content stays the same and the temperature drops, then the relative humidity increases. its vise versa.if the water vapor content stats the same and the temperature rises, the relative humidity decreases. so, yes, i'd say that temperature and humidity have a strong relationship.