Draw the M.O diagram for oxygen molecule calculate its bond order and show that `O_(2)` is paramagnetic.

Explanation

Molecular orbital diagram of oxygen molecule `(O_(2))`:
Electronic configuration of O atom `1s^(2)2s^(2)2p^(4)`
Electronic configuration of `O_(2)` molecule
`sigma_(1s)^(2), sigma_(1s)^(**2), sigma_(2s)^(2), sigma_(2s)^(**2), sigma_(2p_(x))^(2), pi_(2py)^(2), pi_(2py)^(2), pi_(2py)^(**1), pi_(2pz)^(**1)`
Bond order `= (N_(b)-N_(a))/2 = (10-6)/2 = 2`
Molecule has two unpaired electrons hence it is paramagnetic.