Molecular orbital theory

Definition

Molecular Orbital Theory describes the distribution of electrons in molecules where atomic orbitals combine to form molecular orbitals. These molecular orbitals can be occupied by electrons from the molecule as a whole, influencing its chemical properties.

5 Must Know Facts For Your Next Test

1. Molecular orbitals are formed by the linear combination of atomic orbitals (LCAO).
2. There are two types of molecular orbitals: bonding and antibonding.
3. The bond order can be determined by the difference between the number of electrons in bonding and antibonding molecular orbitals divided by two.
4. Molecular Orbital Theory explains phenomena like paramagnetism and diamagnetism in molecules such as $O_2$.
5. In homonuclear diatomic molecules, molecular orbitals are symmetrical about the internuclear axis.

Review Questions

• What is the principle behind the formation of molecular orbitals?
• How do you calculate bond order using Molecular Orbital Theory?
• What distinguishes bonding and antibonding molecular orbitals?

Related terms

Bonding Molecular Orbital: A type of molecular orbital that is lower in energy than the atomic orbitals from which it is formed, leading to a stable interaction between atoms.

Antibonding Molecular Orbital: A type of molecular orbital that is higher in energy than the atomic orbitals from which it is formed, leading to an unstable interaction between atoms.

Linear Combination of Atomic Orbitals (LCAO): A method for constructing molecular orbitals where atomic orbitals are mathematically combined to produce new wave functions.