Question

Consider the ions : $K^{+},S^{2-},C{l}^{-}$ and $C{a}^{2+}.$ The radii of these ionic species follow the order

• A. $C{a}^{2+}>K^{+}>C{l}^{-}>S^{2-}$
• B. $C{l}^{-}>S^{2-}>K^{+}>C{a}^{2+}$
• C. $C{a}^{2+}>C{l}^{-}>K^{+}>S^{2-}$
• D. $K^{+}>S^{2-}>C{l}^{-}>C{a}^{2+}$

Answer 1

Ionic radii $\propto \frac{1}{Z_{eff}}$ $\propto \text{negative}\text{charge}\propto \frac{\text{1}}{\text{positive}\text{charge}}$ Thus, the correct order of ionic radii of these ions is $S^{2-}>C{l}^{-}>K^{+}>C{a}^{2+}$