A. A gas
B. A cloud droplet
C. A rain drop
D. A snowflake
Water vapour, water vapour or aqueous vapour is the gaseous phase of water. It is one state of water within the hydrosphere. Water vapour can be produced from the evaporation or boiling of liquid water or from the sublimation of ice. Unlike other forms of water, water vapour is invisible. Under typical atmospheric conditions, water vapour is continuously generated by evaporation and removed by condensation. It is less dense than air and triggers convection currents that can lead to clouds.
