Question

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

• A. $O_2$
• B. $S_2$
• C. $C_2$
• D. $N_2$

Answer 1

Answer: (C), (D)

$C_2$
$N_2$

$C_2={\left({\sigma }_{1s}\right)}^2<{\left({\sigma }_{1s}^{\ast }\right)}^2<{\left({\sigma }_{2s}\right)}^2<{\left({\sigma }_{2s}^{\ast }\right)}^2<{\left({\Pi }_{2p_x}\right)}^2={\left({\Pi }_{2p_y}\right)}^2{N}_2={\left({\sigma }_{1s}\right)}^2<{\left({\sigma }_{1s}^{\ast }\right)}^2<{\left({\sigma }_{2s}\right)}^2<{\left({\sigma }_{2s}^{\ast }\right)}^2<{\left({\Pi }_{2p_x}\right)}^2={\left({\Pi }_{2p_y}\right)}^2<{\left({\sigma }_{2p_z}\right)}^2{O}_2={\left({\sigma }_{1s}\right)}^2<{\left({\sigma }_{1s}^{\ast }\right)}^2<{\left({\sigma }_{2s}\right)}^2<{\left({\sigma }_{2s}^{\ast }\right)}^2<{\left({\sigma }_{2p_z}\right)}^2<{\left({\Pi }_{2p_x}\right)}^2={\left({\Pi }_{2p_y}\right)}^2<{\left({\Pi }_{{2p}_x}^{\ast }\right)}^1={\left({\Pi }_{{2p}_y}^{\ast }\right)}^1{S}_2=KKLL{\left({\sigma }_{{2p}_z}^{\ast }\right)}^2<{\left({\sigma }_{3s}\right)}^2<{\left({\sigma }_{3s}^{\ast }\right)}^2<{\left({\sigma }_{3p_z}\right)}^2<{\left({\Pi }_{3p_x}\right)}^2={\left({\Pi }_{3p_y}\right)}^2<{\left({\Pi }_{{3p}_x}^{\ast }\right)}^1={\left({\Pi }_{{3p}_y}^{\ast }\right)}^1$

$C_2$ and $N_2$ does not contain unpaired electron so they are diamagnetic.