 Latent heat

The latent heat from phase $\alpha$ to phase $\beta$ isper mole or per particle, according to the normalization used.

Latent heat is the amount of energy required to change the state of a substance without changing its temperature. This energy is absorbed or released during phase transitions, such as melting (solid to liquid), freezing (liquid to solid), boiling (liquid to gas), or condensation (gas to liquid).