question_answer

Among the following groupings which represents the collection of isoelectronic species? (a) \[N{{O}^{+}},CO_{2}^{2-},O_{2}^{-},CO\]      (b) \[{{N}_{2}},C_{2}^{2-},CO,NO\] (c) \[CO,N{{O}^{+}},C{{N}^{-}},C_{2}^{2-}\]         (d) \[NO,C{{N}^{-}},{{N}_{2}},O_{2}^{-}\]

Answer:

                Let us find the number of electrons in each set

a)	Species	No. of electrons
	\[NO+\]	\[7+8-1=14\]
	\[C_{2}^{2-}\]	\[6+6+2=14\]
	\[O_{2}^{-}\]	\[8+8+1=17\]

Not isoelectronic

b)	Species	No. of electrons
	\[{{N}_{2}}\]	\[7+7=14\]
	\[C_{2}^{2-}\]	\[6+6+2=14\]
	\[CO\]	\[6+8=14\]
	\[NO\]	\[7+8=15\]

Not isoelectronic

c)	Species	No. of electrons
	\[CO\]	\[6+8=14\]
	\[N{{O}^{+}}\]	\[7+8-1=14\]
	\[C{{N}^{-}}\]	\[6+8=14\]
	\[C_{2}^{2-}\]	\[6+6+2=14\]

Isoelectronic Therefore the set of species containing CO, \[N{{O}^{+}},C{{N}^{}},C_{2}^{2-}\]are isoelectronic with each other.