Page 3 - 2. Lesson notes- Air, Rain and Air pollution
P. 3
How Are Clouds Formed?
Clouds are formed as a result of water molecules arising from the earth’s surface through
evaporation by the sun as they weigh less. These water vapors cool down as they reach higher
altitudes . Droplets now float in the air and form clusters with other droplets, finally combining
to form huge water masses which appear to us as clouds.
The Water Cycle
It is a cycle involving regular circulation of water in different states of matter. It takes place in
the following stages:
• Water is evaporated i.e., it changes from liquid to gaseous state
• Water is absorbed into the earth’s atmosphere from plants and trees
• Formation of clouds take place as water is converted back into liquid state.
• Water in different forms, dust and other particles in the atmosphere facilitate the
formation of clouds through movement.
• Precipitation falls as rain, snow, drizzle etc., and the cycle continues.
