Question

Which of the following has largest ionic radius?

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

Answer 1

Answer: (A)

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