Difference Between VBT and MOT

Difference Between valence bond theory (VBT) and Molecular orbital theory (MOT)

The main difference between valence bond theory and the molecular orbital theory is that the valence bond theory explains the hybridization of orbitals whereas the molecular orbital theory does not give details about the hybridization of orbitals.

Basis of Comparision	VBT	MOT
Proposed By	Heitler and London in 1927	Hund and Mulliken in 1932
Description	Used to explain the chemical bonding of atoms in a molecule.	Explains the chemical bonding of molecule using hypothetical molecular orbitals.
Hybridization of Molecular Orbitals	Defines the hybridization of molecular orbitals.	Does not define anything about hybridization of orbitals.
Application	Can only be applied for diatomic molecules.	Can be applied on polyatomic molecules.
What The Theory Explains	Bonding of atomic orbitals.	About the mixing of atomic orbitals when forming molecules.
Atom's individual Characteristics	Atoms which are involved in the bond formation, retains their individual characteristic nature.	Atomic orbitals which form molecular orbitals, do not retain their individual characteristic nature.
Bonds Localization	Bonds are localized to two atoms and not molecules	Bonds are localized to both two atoms and molecules.
Electrons	Some of the valence electrons are represented as not shared and not involved in the formation of the molecule.	All the electrons of the valence shell are represented as having taken part in the bonding.
Method Of Obtaining Molecular Orbital	Resulting molecular orbital is obtained by the combination of two wave functions of two unpaired electrons.	Formation of the molecular orbitals is based on the LCAO approximation method, whereby each molecular orbital is constructed from a superposition of atomic orbitals belonging to the atoms in the molecule.
Paramagnetic Nature Of Oxygen	There is no explanation of paramagnetic nature of oxygen	There is an complete explanation of paramagnetic nature of oxygen.
Resonance	Resonance plays an important role.	Resonance does not play any role.

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