Here's why:

* Endothermic processes absorb heat from the surroundings.

* Melting is the process where a solid absorbs heat and transitions into a liquid. This requires energy to break the bonds holding the molecules in a fixed, rigid structure.

Here are some other phase changes and their classifications:

* Freezing (liquid to solid): Exothermic (releases heat)

* Vaporization (liquid to gas): Endothermic (absorbs heat)

* Condensation (gas to liquid): Exothermic (releases heat)

* Sublimation (solid to gas): Endothermic (absorbs heat)

* Deposition (gas to solid): Exothermic (releases heat)