question_answer

Number of unpaired electrons in\[{{O}_{2}}\]molecule is:

A)  zero                                     

B) one

C)  two                                      

D) four

Correct Answer: C

Solution :

The molecular orbital elctronic configuration of\[{{O}_{2}}\]is - \[{{O}_{2}}(16{{e}^{-}})=\sigma 1{{s}^{2}}{{\sigma }^{*}}1{{s}^{2}}\sigma 2{{s}^{2}}{{\sigma }^{*}}2{{s}^{2}}\sigma 2p{{x}^{2}}\] \[\pi 2p{{y}^{2}}\pi 2p{{z}^{2}}{{\pi }^{*}}2p{{y}^{1}}{{\pi }^{*}}2p{{z}^{1}}\] Hence, it has two unpaired Iectrons and B paramagnetic.