Q. The isoelectronic pair is
A) $Cl_{2}O,{ICl}_{2}^{-}$
B) ${Cl}_{2}^{-},\ ClO_{2}$
C) ${IF}_{2}^{+},\ I_{3}^{-}$
D) ${ClO}_{2}^{-},\ {ClF}_{2}^{+}$
Explanation
(d)
$Cl_{2}O = 42\ electrons$
${ICl}_{2}^{-} = 88\ electrons$
${Cl}_{2}^{-} = 35\ electrons$
${IF}_{2}^{+} = 70\ electrons$
$I_{3}^{-} = 160\ electrons$
$Cl_{2}O = 33\ electrons$
${ClO}_{2}^{-} = 34\ electrons$
${ClF}_{2}^{+} = 34\ electrons$
${ClO}_{2}^{-}$ and ${ClF}_{2}^{+}$ contain 34 electrons each hence they are isoelectronic.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.