Answer :
According to collision- coalescence theory, formation of raindrop from cloud droplets occurs when cloud droplets collide and coalesce or stick together.
The only significant difference between a raindrop and a cloud droplet is that a raindrop consist of a velocity that is non-negligible during the fall.
Larger droplets having higher terminal velocities fall faster and collide with smaller droplets. Often the cloud droplets stick together and coalesce to form a larger droplet.
This starts a chain reaction where these bigger droplets fall even rapidly, collide with the other droplets in their path and merge with these droplets.
As droplet and ice crystal size increase, the probability increases that the droplets will burst in the cloud. This is the mechanism behind precipitation. When the clouds become heavy enough due to these droplets or ice crystals, rain or snow is produced that falls to the ground.
To learn more about clouds, refer: https://brainly.com/question/13434971
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