What does the term 'exothermic' specifically refer to?

The term 'exothermic' specifically refers to a process or reaction that releases heat energy to its surroundings. When a chemical reaction or physical process is classified as exothermic, it means that the total energy of the products is lower than that of the reactants, resulting in the excess energy being released, typically in the form of heat.

This release of energy often leads to an increase in the temperature of the surrounding environment, making exothermic reactions critical in various applications, from biological processes like cellular respiration to industrial processes like combustion.

In contrast, the other concepts presented are distinct: the absorption of heat describes an endothermic process, where energy is taken in rather than released. Constant temperature change doesn’t define whether a process is exothermic or endothermic; it merely indicates that temperature remains steady during the reaction. Finally, reversibility of reactions pertains to whether a reaction can go in both directions, which is independent of the heat exchange characteristics of the reaction itself.