A. Generally speaking, the heavier alkaline earth metals can be predicted to exhibit greater shielding of the outer-shell electrons by the inner-shell electrons than lighter alkaline earth metals.
B. Generally speaking, non-metallic elements have greater effective nuclear charge (Zeff) than metallic elements in the same period.
C. Generally speaking, as you go down a group in the periodic table, there is successively less shielding of the outer-shell electrons by the inner-shell electrons.
D. Generally speaking, as you go across a period in the periodic table, the effective nuclear charge (Zeff) increases because each successive element contains more protons in the nucleus than the previous element and the outer electrons are all in the same shell as you go across a period.