State two processes that supply water vapour to the atmosphere.

Evaporation and transpiration are two processes that supply water vapor to the atmosphere.

Evaporation is the process by which liquids are converted into gases. Evaporation occurs at the surface of the liquid as the particles of a liquid are heated and gain kinetic energy. Kinetic energy is the energy of movement. As the liquid particles gain kinetic energy, they begin to move faster and more often. Therefore, the particles begin to move apart. The intermolecular forces between the liquid particles are broken when the particles move far enough apart from one other. Eventually, the particles gain so much kinetic energy that they are able to free themselves from the rest of liquid surface and become gaseous.

Transpiration is simply the evaporation of water that occurs through the leaves, stems, and flowers of trees and other plants.