Question

In dawn,in winter why we see dew drops on leaves of trees

Answer 1

That is frost, water droplets that is present in atmosphere.

Answer 2

The air contains moisture.In early morning specially in winter the temperature is less i.e. , air is cool. At this temperature air cannot hold all the moisture in it. The excess moisture condenses on cool surface like leaves, grass, car glasses, etc in the form of dew drops. Hence we see dew drops on leaves of trees