2nd Ionization Energy

[Rhea Palsule]

During lecture, Dr. Lavelle mentioned that the 2nd ionization energy of an element is always higher. What about an element like magnesium when you have already removed an electron and the electron configuration is now [Ne]3s1? Wouldn't the element be more "willing" to give up another electron so that it is more stable with a full valence shell?

[Chiara R 1K]

I think the reason the second ionization energy would still be higher is that the remaining electron would then experience stronger electrostatic attraction to the positively charged nucleus, and would thus still need more energy to be removed.

[Reine Nakamura 1C]

I would recommend checking out Figure 2.26 on page 55 in the textbook and reading the little paragraph next to it... Helped me a lot! It shows that for Group 2 elements, such as Mg, they have similar second and first ionization energies as both electrons are in the 3s subshell rather than in a noble gas core. While the 3s subshell is "willing" to give up it's electrons more readily than would a noble gas core, the second ionization energy is still higher.