Why may heavy rainfall not form when a cloud has many droplets but the droplets are very small?

Correct answer: Because small droplets may remain suspended due to insufficient weight

Answer: A. The number of droplets is not the same as their ability to produce rain. Very small droplets have little mass, so their gravitational force is weak compared with air resistance and upward air motion. They can therefore remain suspended in the cloud. For heavy rainfall, droplets generally need to grow through collision and coalescence, becoming sufficiently large and heavy to fall rapidly. Even after falling, they must survive evaporation in the air below. A is correct because insufficient size and weight can prevent small droplets from falling as rain. B is wrong because every water droplet contains water by definition. C and D are unrelated and scientifically impossible. Memory cue: “Many tiny drops are not equal to a few large, heavy drops.”