Question

The ion which is isoelectronic with $CO$ is:

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

Answer 1

The correct option is A $C{N}^{-}$

Isoelectronic species are those species which have the same number of electrons. Out of the given ions, $C{N}^{-}$ is the ion which has 14 electrons (6 from carbon, 7 from nitrogen and 1 from the negative charge). Thus $C{N}^{-}$ ion is isoelectronic with $CO$.