Question

According to molecular orbital theory, the paramagnetism of $O_2$ molecule is due to presence of

• A. Unpaired electrons in the bonding $\sigma$ molecular orbital
• B. Unpaired electrons in the anti- bonding $\sigma$ molecular orbital
• C. Unpaired electron in the bonding $\pi$ molecular orbital
• D. Unpaired electrons in the anti - bonding $\pi$ molecular obrital

Answer 1

The correct option is D Unpaired electrons in the anti - bonding $\pi$ molecular obrital

The reason that it is paramagnetic is because the oxygen molecule has two unpaired electrons. Electrons not only go around the atom in their orbitals, they also spin, which creates a magnetic field. The reason that it is paramagnetic is because the oxygen molecule has two unpaired electrons.

The last two electrons go into separate, degenerate π orbitals, according to Hund's Rule. Thus, oxygen has two unpaired electrons and is paramagnetic

Option D is a correct answer.