Among the following molecules/ions `C_(2)^(2-),N_(2)^(2-),O_(2)^(2-),O_(2)`
Which of one diamagnetic and has the shortest bond length?

Options

A. `C_(2)^(2-)`
B. `O_(2)^(2-)`
C. `O_(2)`
D. `N_(2)^(2-)`

Answer

A

Explanation

`C_(2)^(-2) to sigma1s^(2), sigma^(***)1s^(2), sigma2s^(2), sigma^(***)2s^(2), [pi 2Px^(2)= pi 2Py^(2)]sigma2Pz^(2)`
Bond order `=(10-4)/(2)=3` (diam agnetic)
`N_(2)^(-2) to sigma1s^(2), sigma ^(***)1s^(2), sigma2s^(2), sigma^(***)2s^(2), [pi 2P_(x)^(2)=pi 2P_(y)^(2)] sigma2P_(z)^(2)[pi^(***)2P_(x)^(1)=pi^(***)2P_(y)^(1)]`
`B.O=(10-6)/(2)=2` (Param agnetic)
`O_(2)^(-2) to sigma1s^(2), sigma***1s^(2), sigma2s^(2), sigma***2s^(2), sigma2P_(z)^(2)[pi2P_(x)^(2)=pi 2P_(y)^(2)][pi ***2P_(x)^(2)=pi ***2P_(y)^(2)]`
`B.O=(10-8)/(2)=1` (Diam agnetic)
`O_(2) to sigma1s^(2), sigma***1s^(2), sigma2s^(2), sigma***2s^(2), sigma2P_(z)^(2)[pi2P_(x)^(2)=pi 2P_(y)^(2)][pi***2P_(x)^(1)=pi ***2P_(y)^(1)]`
`B.O=(10-6)/(2)=2` (Param agnetic) `" " B.O prop (1)/(BL)`