An endothermic phase change is a process in which a substance absorbs energy, typically in the form of heat, from its surroundings to change its state. This can occur in transitions such as melting, vaporization, or sublimation. For instance, when ice melts to become water, it absorbs heat from the environment. This absorption of energy is necessary to overcome the forces holding the molecules in a solid state, allowing them to move apart and enter a liquid state.
The term ‘endothermic’ refers to the absorption of heat. Therefore, in an endothermic phase change, the substance gains energy, which is reflected in a temperature change or a physical state change. Understanding this process is essential in fields like chemistry and physics, particularly when studying thermodynamics and energy transfer.