Answer
See the answer below.
Work Step by Step
a) Se, atomic radius grows in later periods, Se is in the fourth period, S and Cl are in the third.
b) $Br^-$, anions have bigger radii than their neutral counterpart due to electronic repulsion
c) Na, in the second ionization an electron would have to be removed from an inner shell since it's in group 1.
d) N, ionization energy is greater in earlier periods, N is in the second period, P in the third, As in the fourth.
e) $N^{3-}$, ionic radius increases with a more negative charge.
