Which one of the following molecules is expected to exhibit diamagnetic behaviour?

Options

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

Answer

A, B

Explanation

`C_(2)(6+6=12)=sigma1s^(2), overset(***)sigma 1s^(2), sigma2s^(2), overset(***)sigma2s^(2), pi 2p_(y)^(2) `
Since, all the electrons are paired, it is a diamagnetic species.
`N_(2)(7+7=14)=sigma1s^(2), overset(***)sigma1s^(2), sigma2s^(2), overset(***)sigma2s^(2), pi 2p_(x)^(2)=pi 2p_(y)^(2), sigma2p_(z)^(2)`
It is also a diamagnetic species because of the absence of unpaired electrons.
`O_(2)(8+8=16) or S_(2)=sigma1s^(2), overset(***)sigma1s^(2), sigma2s^(2), overset(**)sigma2s^(2), sigma2s_(z)^(2), pi 2p_(x)^(2)=pi2p_(y)^(2), overset(***)pi2p_(x)^(1)=overset(***)pi2p_(y)^(1)`
Due to the presence of two unapired electrons, `O_(2)` and `S_(2)` both are paramagnetic molecules.