| Electron Gain Enthalpy | Electronegativity |
|---|---|
| It is the tendency of an isolated gaseous atom to attract an electron. | It is the tendency of an atom in a molecule to attract the shared pair of electrons. |
| It is the property of isolated atoms. | It is the property of a bonded atom. |
| It is the absolute electron attracting power of an atom. | It is the relative attracting power of an atom. |
| It can be experimentally measured. | It cannot be measured experimentally. It is only a relative number. |
| It has units such as kJ mol-1 or eV/atom. | It has no units. There are only scales for comparison. |
| The electron gain enthalpy of an atom is constant. | The electronegativity of an atom is not constant. It depends upon the oxidation state of an atom, hybridization state of the atom and the nature of substituents attached to it. |
