- Evaporation: This is the process by which water molecules at the surface of a liquid or solid change into gas molecules and rise into the atmosphere. Evaporation occurs when the temperature of the water is high enough to cause the molecules to move quickly enough to escape from the liquid or solid.
- Sublimation: This is the process by which water molecules at the surface of a solid change directly into gas molecules without first becoming a liquid. Sublimation occurs when the temperature of the ice is low enough to cause the molecules to move slowly enough to escape from the solid.
-Transpiration: This is the process by which plants release water vapour into the atmosphere through their leaves. Transpiration occurs when the plant absorbs water from the ground through its roots and then releases it into the atmosphere through tiny openings called stomata on the leaves.