Question

Which of the following cannot be explained by VBT?

• A. Overlapping of orbitals
• B. Bond formation
• C. Paramagnetic nature of $O_2$
• D. None of these

Answer 1

The correct option is C Paramagnetic nature of $O_2$

Valence bond theory (VBT) predicted that there will be $\pi$-bond in $O_2$ molecule via lateral overlapping. It did not explain anything about the magnetic properties of the molecule.

However, it is experimentally observed that $O_2$ is actually paramagnetic.
This was later explained through Molecular orbital theory (MOT) by introducing bonding and anti-bonding orbitals concept.
Both the overlapping of atomic orbitals and the bond formation can be explained by VBT.