Question

Which of the following has largest ionic radius?

• A. $C{s}^{+}$
• B. $L{i}^{+}$
• C. $N{a}^{+}$
• D. $K^{+}$

Answer 1

The correct option is A $C{s}^{+}$

Atomic and ionic radii increase from top to bottom in a group due to the inclusion of another shell at every step. Hence, $C{s}^{+}$ ion will be the largest among given IA group ions, i.e.,
$N{a}^{+},L{i}^{+}$ and $K^{+}$.