Electron affinity enthalpy is the enthalpy change associated with a gaseous atom gaining an electron, expressed per mole in kilojoules per mole (kJ/mol). It is the molar, constant-pressure counterpart of the electron affinity. For most elements it is a negative (exothermic) quantity.

电子亲和焓是与气态原子获得一个电子相关的焓变,以每摩尔的千焦每摩尔(kJ/mol)表示。它是电子亲和能的每摩尔、恒压对应量。对大多数元素而言,它是负值(放热)。