Consider the following orderings.
I. Al

Question

Consider the following orderings.
I. Al < Si < P < Cl
II. Be < Mg < Ca < Sr
III. I < Br < Cl < F
IV. Na + < Mg 2+ < Al 3+ < Si 4+ 
-Which of the following statements is true of second ionization energies?
A) That of Al is higher than that of Mg because Mg wants to lose the second electron, so it is easier to take the second electron away.
B) That of Al is lower than that of Mg because the second electron taken from Al is in a p orbital, so it is easier to take away.
C) That of Al is lower than that of Mg because Mg wants to lose the second electron, so the energy change is greater.
D) The second ionization energies are equal for Al and Mg.
E) That of Al is higher than that of Mg because the electrons are taken from the same energy level, but the Al atom has one more proton.

Quizplus · Accepted Answer

The second ionization energy of Al is higher than that of Mg because after losing one electron, Mg achieves a stable noble gas configuration (Ne), making it less willing to lose a second electron. Al, on the other hand, after losing one electron, still does not achieve a noble gas configuration and has a higher nuclear charge due to one more proton, making it harder to remove the second electron.

Consider the Following Orderings