$\begin{array}{1 1} \text{A. Atomic radius of the elements increases as one moves down the first group of the periodic table } \\ \text{b. Atomic radius of the elements decreases as one moves across from left to right in the 2nd period of the} \\\text{
c.Amongst isoelectronic species, smaller the positive charge on the cation, smaller is the ionic radius } \\ \text{
d. Amongst isoelectronic species, greater the negative charge on the anion, larger is the ionic radius}
\end{array} $
