Which of the following diatomic molecular species has only `pi` bonds according to Molecular orbital Theory

Options

A. `O_2`
B. `N_2`
C. `C_2`
D. `Be_2`

Answer

C

Explanation

`sigma1s^2,sigma^(**)1s^2,sigma^(**)2s^2,pi2p_x^2=pi2p_y^2`
Double bond in `C_2` consists of both `pi` bonds because of the presence of four electrons in two `pi` molecular orbital. In other molecule a double bond is made up of a sigma bond and a pi bond.