# What is the difference between bonding and antibonding molecular orbitals?

The molecular orbital theory states that each atom tends to combine together and form molecular orbitals. As a result of such arrangement, electrons are found in various atomic orbitals and they are usually associated with different nuclei. In short, an electron in a molecule can be present anywhere in the molecule.

## Molecular orbitals

The space in a molecule in which the probability of finding an electron is maximum can be calculated using the molecular orbital function. Molecular orbitals are basically mathematical functions that describe the wave nature of electrons in a given molecule.

### Types

According to the molecular orbital theory, there exist three primary types of molecular orbitals that are formed from the linear combination of atomic orbitals.

• Bonding molecular orbital
• Anti bonding molecular orbital

## Difference between Bonding molecular orbital and Anti bonding molecular orbital

Difference between Bonding molecular orbital and Anti bonding molecular orbital is tabulated below

Bonding molecular orbital

## Anti Bonding molecular orbital

Molecular orbitals formed by the additive effect of the atomic orbitals is called bonding molecular orbitals Molecular orbitals formed by the subtractive effect of atomic is called anti-bonding molecular orbitals
Probability of finding the electrons is more in the case of bonding molecular orbitals Probability of finding electrons is less in antibonding molecular orbitals. There is also a node between the anti-bonding molecular orbital between two nuclei where the electron density is zero.
These are formed by the combination of + and + and – with – part of the electron waves These are formed by the overlap of + with – part.
The electron density, in the bonding molecular orbital in the internuclear region, is high. As a result, the nuclei are shielded from each other and hence the repulsion is very less. The electron density in the antibonding molecular orbital in the internuclear region is very low and so the nuclei are directly exposed to each other. Therefore the nuclei are less shielded from each other.
The bonding molecular orbitals are represented by σ, π, δ. The corresponding anti-bonding molecular orbitals are represented by σ∗ , π∗, δ∗.