Of the following sets ,which one does not contain isoeletronic species ?

Options

A. `PO_4^(3-), SO_4^(2-), ClO_4^-`
B. `CN^-, N_2, C_2^(2-)`
C. `SO_3^(2-),CO_3^(2-), NO_3^-`
D. `BO_3^(3-), CO_3^(2-), NO_3^-`

Answer

C

Explanation

(A) `PO_4^(3-)` (No. of electrons = 15+8 x 4+3=50)
`SO_4^(2-)` (No. of electrons= 16+8 x 4+2=50)
`ClO_4^(-)` (No. of electrons = 17 + 8 x 4 + 1 = 50)
(B) `CN^(-)` (No. of electrons = 6 + 7 + 1 = 14)
`N_2` (No. of electrons=2 x 7= 14)
`C_2^(2-)` (No. of electrons=2 x 6 +2 =14 )
(C) `SO_3^(2-)` (No. of electrons=16 + 3 x 8 + 2 = 42)
`CO_3^(2-)` (No. of electrons =6+8 x 3 +2=32)
`NO_3^(-)` (No. of electrons = 7+8 x 3+1 = 32)
(D) `BO_3^(3-), CO_3^(2-), NO_3^(-)` (Each of these ions have 32 electrons each)
Thus `SO_3^(2-), CO_3^(2-)` and `NO_3^(-)` are not isoelectronic.