Question

What is ionization energy

Answer 1

It is the amount of energy needed to convert 1 mole of a substance (an atom or molecule) into an 1+ ion by removing 1 electron. This is the first ionization energy and hence somtimes used as a general definition for the ionization energy.

The 2nd ionization energy would be removing another (1) electron from an ion (formed in the 1st ionization energy) to 2+ ions

Hope this helps

Answer 2

Ionization energy is the quantity ofenergy that an isolated, gaseous atom in the ground electronic state must absorb to discharge an electron, resulting in a cation. This energy is usually expressed in kJ/mol, or the amount of energy it takes for all the atoms in a mole to lose one electron each.