Q. Which one of the following ions has the highest value of ionic radius?
A) $Li^{+}$
B) $B^{3 +}$
C) $O^{2 -}$
D) $F^{-}$
Explanation
(c)
All the ions belong to same period thus for them cations will be smaller than anions. Now, $O^{2 -}$and $F^{-}$are isoelectronic and $r_{n} \propto \frac{1}{Z}$
Thus, ionic radius of $O^{2 -}(Z = 8) > F^{-}(Z = 9).$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.