Question

What ionisation enthalpy mean?

Answer 1

Theionization energy(IE) is qualitatively defined as the amount ofenergyrequired to remove the most loosely bound electron, the valence electron, of an isolated gaseous atom to form a cation. It means if you want to remove the last electron from an atom, then the amount of energy needed to remove it from the gaseous state of the element is the ionisation energy of the element.