- These are the tiny water droplets present in the air.
- Water vapour comes into the air from evaporation of water present on the earth(in ponds, lakes, rivers and oceans etc) and from transpiration.
- The presence of water vapours is essential for the cycling of water in nature.
Activity to prove that air contains water vapour:
When air comes in contact with a cool surface, it condenses and drops of water vapour appear on the cooled surface.
This shows that air contains water vapours.