Both electron gain enthalpy and electronegativity referred to tendency to attract electron but electron gain enthalpy refers to the introduction of electron to the outer most shell of an isolated gaseous atom where as electronegativity refers to the tendency of an atom of an element to attract tha shared pair of eletron towards itself in a covolent bond
Electron gain enthalpy means that the energy released when an electron is added in a gaseous isolated atom or ion.Electronegativity means the ability of an atom in a chemical compound to attract shared electrons towards itself is called electro negativity.