Question

What is the significance of molecular orbitals theory?

Answer 1

In Molecular Orbital Theory, the electrons don't belong to the individual atoms, they belong to the whole molecule. When the atomic orbitals come together they create a new set of orbitals called molecular orbitals. We get a bonding orbital and an antibonding orbital. In the formation of the molecule, there are spaces where the electrons will be attracted (bonding orbitals) and spaces where they will be repelled (antibonding orbitals). How well the atoms bond in the molecule depends on the balance between bonding and antibonding orbitals (called bond order). The bigger the bond order, the stronger the bond.