Which of the following sets correctly represents a group of strictly isoelectronic species? — Atomic Structure Chemistry Question

💡 Solution & Explanation

Isoelectronic species are those that possess the exact same total number of electrons. Calculating for option A: $CO$ has $6(C) + 8(O) = 14$ electrons. $CN^-$ has $6(C) + 7(N) + 1 = 14$ electrons. $NO^+$ has $7(N) + 8(O) - 1 = 14$ electrons. $C_2^{2-}$ has $6 \times 2 + 2 = 14$ electrons. Since all species in option A have exactly $14$ electrons, they form an isoelectronic set.