Question

in what form of energy does heat energy in a hot area do change into if a sudden rain fall occurs assuming conservation of energy

Answer 1

The water absorbs the heat so its still in the form of heat energy

Answer 2

Thermal Energy.

to further explain. according to the laww of conservation of energy, energy can be neither created nor destroyed. But energy can be transfered from one object to another, between the systems to surroundings

think of the hot area as the system and the rain as the surroundings. once the rainfall hits the hot surface, the thermal energy will be transfers from the hot ground to the rain (system to surroundings).

as the 2 are exchanging thermal energy, the temperature of the hot ground will derease in temp as the temperature of the rain will increase, until both reaches the same constant temp ( at thermal equilibrium)

Answer 3

then what about the internal energy of the atoms of the surface area

Answer 4

Internal energy of the surface molecules is directly proportional to the absolute temp so that decreases too.
\[U=f/2kT ^{2}\]

f is the degree of freedom of the molecule

Answer 5

And it's almost impossible to keep the exact track of the energy change for practical purposes as this is not a rigid body, so there'll be changes in the elastic potential energy of the water drops after collision