Melting means changing from a solid into a liquid by adding heat energy.
When a substance melts, it changes phase from a solid to a liquid by the application of heat.
Changing the phase of a solid can be done by adding heat energy.
What can be done to a solid by adding heat energy?

a) massive damage
b) phasing the bubbles
c) It expands
d) cooling the center
e) Evaporation
f) changing the phase
g) removing the air
h) Water expanding