Question

The ion which is isoelectronic with $CO$ is

• A. $C{N}^{-}$
• B. $O_2^{-}$
• C. $N_2^{+}$
• D. $O_2^{+}$

Answer 1

Answer: (A)

Isoelectronic species are the having same number of electrons.
Number of electrons in $CO=6+8=14$
Number of electrons in $O_2^{-}=16+1=17$
Number of electrons in $N_2^{+}=14-1=13$
Number of electrons in $O_2^{+}=16-1=15$
Number of electrons in $C{N}^{-}=6+7+1=14$
Hence, $CO$ isoelectronic with $C{N}^{-}$ion.