Question

Which of the following is not isoelectronic series?

• A. $C{l}^{-},P^{3-},Ar$
• B. $N^{3-},Ne,M{g}^2$
• C. $B^3,He,Li$
• D. $N^{3-},S^{2-},C{l}^{-}$

Answer 1

The correct option is D

$N^{3-},S^{2-},C{l}^{-}$

$N^{-3}\to 7+3=10e^{-}=S^{2-}\to 16+2=18e^{-};C{l}^{-}=17+1=18e^{-}$

They are not a set of isoelectronic species as they have a different number of electrons.