The relationship between ionization 2 and ionization 3 is this: IONIZATION 3 IS GREATER THAN IONIZATION 2.
Ionization energy is the energy that is required to remove the most loosely bound electrons from an element. Elements that have low ionization energy will give up their valence electrons easily. For instance, metals generally have low ionization energy. The energy that is required for third ionization energy is greater than that for second ionization energy, because, the energy that is required to remove three electrons from an element is greater than that required to remove two electrons from an element.