Indicate the correct order for ionization energy:

Explanation

This is because it takes more energy to remove an electron from an atom that already has a positive charge. The first ionization energy (I.E1) is the energy required to remove the first electron from a neutral atom. The second ionization energy (I.E2) is the energy required to remove the second electron from a singly charged positive ion. The third ionization energy (I.E3) is the energy required to remove the third electron from a doubly charged positive ion.As you remove electrons from an atom, the remaining electrons are held more tightly to the nucleus. This is because the positive charge of the nucleus is not as effectively shielded by the remaining electrons.