What is a reaction called that absorbs heat?

The term that describes a reaction which absorbs heat is known as "endothermic." In an endothermic reaction, the system takes in heat energy from its surroundings, leading to a drop in temperature of the surrounding environment as energy is absorbed to facilitate the reaction. This concept is significant in various scientific and engineering fields, including thermodynamics and chemistry.

In contrast, exothermic reactions release heat, resulting in an increase in temperature in the surroundings. Isothermic processes maintain a constant temperature throughout, while catalytic processes involve catalysts that speed up a reaction without being consumed. Each of these terms highlights distinct characteristics of thermal and chemical processes, but the specific action of heat absorption is accurately captured by the term endothermic.