Water vapour is water in its gaseous state. It is invisible, so you can't see it. Water vapour is found in the air all around us. It is the reason why we have clouds and rain.
Water vapour is the gas form of water.
Noun: the gaseous state of water.
Adjective: relating to water vapour.
The word "water vapor" comes from the combination of the words "water" and "vapor".
The word "water" comes from the Old English word "wæter", which means "water".
The word "vapor" comes from the Latin word "vapor", which means "steam" or "mist".
The first recorded use of the word "water vapor" was in the 17th century.
Where might you find water vapour?