why is energy required for the heating or boiling process?

Answer 1

In order to boil the molecules must attain enough energy to break free from each other and to exceed the atmospheric pressure pushing down on the liquid. This is the heat of vaporization. Energy in the form of heat is required to make this happen.

Answer 2

Heat itself is energy. If you need more heat you need to use more energy. Boiling also needs energy though boiling points of different liquids are not the same.

Answer 3

Something has to make the molecules move quicker.

Answer 4

heat is a catalyst