Question

Which one of the following is correct order of the size?

• A. $I>I^{-}>I^{+}$
• B. $I>I^{+}>I^{-}$
• C. $I^{+}>I^{-}>I$
• D. $I^{-}>I>I^{+}$

Answer 1

Answer: (D)

The size of the cation is always smaller than that of its parent atom and size of the anion is always larger than that of its parent atom.
$\therefore$ Size of the cation $\propto \frac{1}{\text{ magnitude of positive charge }}$
Size of the anion $\propto$ magnitude of negative charge
Hence, the correct order of the size is $I^{-}>I+I^{+}$