Question

The electronic configuration of carbon is `1s^(2) 2s^(2) 2p^(2)`.
There are 12 electrons in `C_(2)` . The correct electronic configuration of `C_(2)` molecule is
A. `(sigma1s^(2))(sigma^(**)1s^(2))(sigma2s^(2))(sigma^(**)2s^(2))(sigma2p_(z)^(2))(pi2p_(x)^(2))`
B. `(sigma1s^(2))(sigma^(**)1s^(2))(sigma2s^(2))(sigma^(**)2s^(2))(pi2p_(x)^(2)=pi2p_(y)^(2))`
C. `(sigma1s^(2))(sigma^(**)1s^(2))(sigma2s^(2))(sigma^(**)2s^(2))(sigma2p_(z)^(2))(pi2p_(x)^(1)=pi2p_(y)^(1))`
D. `(sigma1s^(2))(sigma^(**)1s^(2))(sigma2s^(2))(sigma^(**)2s^(2))(pi2p_(x)^(2)=pi2p_(y)^(1))`

Answer 1

Correct Answer - B
For atoms like nitrogen and below N in atomic number have higher energy for `p_(z) `- orbital, hence the configuration for `C_(2)` molecule is
`(sigma 1s^(2))(sigma^(**)1s^(2))(sigma2s^(2))(sigma^(**)2s^(2))(pi 2p_(x)^(2)=pi2p_(y)^(2))`.