(a) It is also called sublimation.
The term sublimation is the passage or the transformation or conversion that substances undergo when passing from one state to another, for example from a solid substance to gas. Sublimation finds practical application in forensic sciences. Dye-sublimation printers help in rendering digital pictures in a detailed and realistic fashion which helps in the analysis of substances.
(b) The amount of heat energy required to change 1 kg of a solid into liquid at atmospheric pressure at its melting point is known as the latent heat of fusion.
Latent heat of fusion, also known as enthalpy of fusion, is the amount of energy that must be supplied to a solid substance (typically in the form of heat) in order to trigger a change in its physical state and convert it into a liquid (when the pressure of the environment is kept constant).