Question

what is reason that rainfall occurs in drops and not in continuous stream

Answer 1

There are two perfectly good reasons why rain cannot fall as streams.. The first reason is that a rain cloud is not a tank, and the water in it is not in a liquid state. A cloud is just a great mass of vapor, in which the water is as finely divided as in fog or steam. When the cloud is blown upon by a current of cold air, the vapor runs together, turning to liquid, or the form in which we know it as water. But it cannot form a mass of water in the air, because it hasn't time before it gets so heavy that it falls And vapor always condenses on something solid, as you can see it do on a window-pane or the outside of a pitcher of ice-water The only solid things in the air are particles of dust. Using a grain of dust as a center of attraction, vapor condenses on it in just as big drops as the air will hold up. As that amount is very small, indeed, the vapor in a cloud falls in millions of little round drops, and each drop has a tiny grain of dust in the very center No wonder the sky looks as if it had had its face washed after a rain!