Assuming `2s-2p` mixing is not operative, the paramagnetic species among the following is

Options

A. `Be_(2)`
B. `B_(2)`
C. `C_(2)`
D. `N_(2)`

Answer

C

Explanation

If `2s - 2p ` mixing is not operative , then molecular
orbitals may be arranged in order of energy as follows :
`sigma (1s), sigma^(**) (1s), sigma(2s), sigma^(**) (2s), sigma(2p_(z)), pi(2p_(x))`
`= (2p_(y)), pi^(**) (2p_(x)) = pi^(**) (2p_(y)), sigma^(**) (2p_(z))`
Applying this configuration , `Be_(2), B_(2) and N_(2)` will
be diamgnetic but `C_(2)` will be paramagnetic .