Question 21N.1.hl.TZ0.5

Which statement explains why the second ionization energy of aluminium is higher than the first ionization energy of magnesium?

A.  Ionization energy increases along period 3.

B.  3p electrons are at a higher energy level than 3s electrons.

C.  3p electrons are further away from the nucleus than 2p electrons.

D.  Both have the same number of electrons and aluminium has one more proton.