processesendotermisista

processesendotermisista refers to endothermic processes in thermodynamics, i.e., processes in which a system absorbs heat from its surroundings. In these processes the heat flow into the system is positive, and the enthalpy change is typically positive at constant pressure. The term is used in multilingual or cross-disciplinary contexts to denote endothermic reactions and transformations.

Under the first law of thermodynamics, the change in internal energy is ΔU = q + w, so endothermic processes involve heat input that can raise the system’s energy. At constant pressure, the heat exchanged with the surroundings equals the enthalpy change, so ΔH = qp and qp > 0 for endothermic steps. The exact temperature response depends on the system’s heat capacity and any work performed by or on the system.

Common examples include melting of a solid, vaporization of a liquid, and sublimation of a solid, all of which require energy input. Dissolution processes can also be endothermic, such as dissolving certain salts in water. Biological and atmospheric processes—such as photosynthesis and some phase transitions in clouds—also involve endothermic steps.

Measurement and analysis often rely on calorimetry. Calorimeters quantify heat flow to or from a system, while differential scanning calorimetry characterizes phase transitions and enthalpy changes. Processesendotermisista are contrasted with exothermic processes, where heat is released to the surroundings.