Q. Which of the following is the smallest in size?
A) $Na^{+}$
B) $F^{-}$
C) $O^{2 -}$
D) $N^{3 -}$
Explanation
(a)
$Na^{+} < F^{-} < O^{2 -} < N^{3 -}$
All are isoelectronic. Effective nuclear charge is highest for $Na^{+}$, so it has the smallest size
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.