10. cloud droplets form and grow as water vapor condenses onto hygro-
scopic condensation nuclei. research has shown that the maximum
radius for cloud droplets is about 0.05 millimeter. however, typical
raindrops have volumes thousands of times greater. explain how cloud
droplets become raindrops.

According to collision- coalescence theory, formation of raindrop from cloud droplets occurs when cloud droplets collide and coalesce or stick together.

Explanation:

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.