Question

The second ionization energy of alkaline earth metals is less than that of corresponding alkali metals because

Answer 1

The second ionization energy of alkaline earth metals is less than that of corresponding alkali metals because& in alkali metals the second electron is to be removed from a cation, which has already acquired a noble gas configuration. In the case of alkaline earth metals the second electron is to be removed from a monovalent cation, which still has one electron in the outermost shell. Thus, the second electron can be removed more easily in the case of group 2 elements than in group 1 elements.