why is energy required for the melting or boiling rocess?

Question

why is energy required for the melting or boiling rocess

Answer 1

for ionic compounds, you usually need to heat them to high temperatures in order to melt them because the forces of attractions between the ions of opposite charge are strong. it takes a lot of energy to break the well-organized network of bound ions. the same applies to boiling...there are forces of attraction between the molecules of a substance that need to be overcome so that it will change into gaseous form.

Answer 2

Melting and boiling involves an increase in the kinetic energy of the atoms and molecules of the material in question. This increase in energy must be supplied by an external source, e.g., heat or microwaves.

Answer 3

It varies with different materials. For water, it takes 144 BTU/lb to melt ice and 1000 BTU/lb to boil water into steam.