What is precipitation?

Hint: Water cycle or the hydrological cycle is the natural process by which water changes its state from one phase to another, but the total number of water particles remains the same. There are four stages in which this process takes place— evaporation, condensation, precipitation and infiltration or runoff. Evaporation is the first stage in which water from the earth’s surface (mainly the water bodies) changes into water vapour because of the heat from the sun. Condensation is the process by which the accumulated water vapour in the atmosphere cools down in lower temperatures. Precipitation is explained below.

Complete answer: Precipitation is the process by which takes place once the water vapour condenses to form water droplets in clouds and once they become heavy enough, fall to the ground in various forms. These forms include rainfall, snowfall, hail, etc. Particles of dust or smoke in the atmosphere form the condensation nuclei and provide a surface for water vapour to condense upon. This helps water droplets gather together and become large enough to fall to the Earth. Precipitation is always freshwater, however, they can be contaminated by pollutants while falling to earth. This is referred to as acid rain.

Note: The last stage of the water cycle is infiltration by which rainwater seeps into the ground forming aquifers. If the water from rainfall does not form aquifers, it flows into rivers or the sea and this process is called runoff. The water cycle is an integral part of the earth’s climate and it affects all life processes on earth.