Question

The paramagnetic property of oxygen as well explained by:
A.Molecular orbital theory
B.Resonance theory
C.Valence bond theory
D.VSEPR theory

Answer 1

Due to valence bond theory or Lewis bonding which can predict two unpaired electrons in oxygen. Electrons not only go around the atom in their orbitals, they also spin, which creates a magnetic field. Unpaired electrons spin in the same directions as each other, which increases the magnetic field effect.

Complete step by step answer:
We now turn a molecular orbital description of the bonding in oxygen. It so happens that the molecular orbital description of the molecule provided an explanation for a long-standing puzzle that could not be explained using other bonding models.
This behavior was for oxygen to have unpaired electrons, making it paramagnetic. This result was one of the earliest triumphs of molecular orbital theory over the bonding approaches. As we know oxygen has two unpaired electrons.
The Lewis structure of ${O_2}$ gives a misleading impression.
The atomic orbitals of the O atoms overlap to form orbitals of the oxygen molecules. We add 12 valence electrons according to the Aufbau principle.
The last two electrons go into separate, degenerate states according to Hund’s rule.
Thus, oxygen has two unpaired electrons and is paramagnetic.
So here molecular orbital theory is explained by the paramagnetic property.

Therefore, option (A) is the correct answer.

Note: Molecular orbital theory is explained by paramagnetic property of oxygen. Molecular orbital theory is dependent on unpaired electrons. It showed that oxygen contains paramagnetic property. So due to the unpaired electron, molecular orbital theory explains the paramagnetic property of oxygen.