Answer
See the answer below.
Work Step by Step
Ionization energy increases from left to right and bottom up in the periodic table, so
a) $S(G16, P3)\lt O(G16, P2)\lt F(G17, P2)$
b) O, all these three are in group 16, and oxygen is in the second period.
The negative of electron attachment energy increases from left to right and bottom up in the periodic table, so
c) Cl, is in the third period, the others are in the fourth.
Radius is bigger in more negatively charged ions, so
d) $O^{2-}$
