Answer
The amount of heat required to change the solid to a liquid is called heat of fusion.
The amount of heat required to change the liquid to a vapor is called heat of vaporization.
Work Step by Step
Melting needs only enough energy for their molecules to escape from their sites in the solid.For vaporization, enough energy must be supplied to break most of the inter molecular attractions. Hence, heat of fusion of a substance is smaller than its heat of vaporization.
