Melting, a phase transition from solid to liquid, can be either exothermic or endothermic depending on the substance. In exothermic melting, energy is released as the solid melts, while in endothermic melting, energy is absorbed. The direction of energy flow determines the sign of the enthalpy change: positive for exothermic and negative for endothermic. Understanding these concepts is crucial for analyzing phase transitions and their significance in various applications.
