Dew accumulates on the grass, why does not the dew fall on the leaves of the tree?
Answer: Dew accumulates on the grass, but not on tree leaves. Since leaves are above the ground, the air in contact with them descends colder and heavier, and other cooler and lighter air fills the space. As a result, the surface near the leaves of the tree does not fall below the dew point. But because the grass is near the surface, it is exposed to cold, heavy air longer, and the altitude of the land-adjacent atmosphere drops below the dew point. So the dew accumulates on grass, not on the leaves of the tree.