Question

it is seen that temperature of remaining liquid drops when evaporation takes place from its upper surface explain

Answer 1

evaporation is a surface phenomenon . the particles of liquid absorb the energy from the surroundings to regain the energy lost during the change of state from liquid to gas or evaporation. this absorption of energy from surroundings make the surrounding cool.

Answer 2

The molecules which have more energy come to the surface and are evaporated whereas the molecules with lower energy are left in the remaining liquid.The evaporating molecules take energy(heat) from the liquid and due to this temperature of the remaining liquid falls.