Ionisation Energy (IE or Ei) is the quantity of energy required to remove one electron from the valence shell of an atom in a gas phase and in its ground electronic state. This is expressed as kilojoules per mole (kJ/mol) or kilocalories per mole (kcal/mol), which represents the quantity of energy involved in the removal of one electron from each atom in one mole of substance. The quantity in Physics is expressed in electron volts.
Published on: 28 Jul 2017 at 2214. Last updated: 7 Jul 2018 at 1538.