Question

The radii of $F , F ^{-}, O$ and $O ^{-2}$ are in the order of

• A. $O ^{2-}> O > F ^{-}> F$
• B. $F ^{-}> O ^{2-}> F > O$
• C. $O ^{2-}> F ^{-}> F > O$
• D. $O ^{2-}> F ^{-}> O > F$

Answer 1

Answer: (D)

$O ^{2-}> F ^{-}> O > F$

Answer 2

We know that anion is always larger than the corresponding atom therefore $F ^{-}> F$ and $O ^{2-}> O$ Also, in a period, size of the atom decreases from left to right due to greater force of attraction exerted correct order is : $O ^{2-}> F ^{-}> O > F$