$\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 left to right in the 2ndperiod of the ionic radius} \\\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} $
