Molecular orbital diagram

Definition

A molecular orbital diagram is a graphical representation that shows the relative energy levels of molecular orbitals formed from atomic orbitals during the bonding process in a molecule. It helps visualize the bonding, anti-bonding, and non-bonding interactions between atoms.

5 Must Know Facts For Your Next Test

1. Molecular orbital diagrams are constructed based on the linear combination of atomic orbitals (LCAO) method.
2. Bonding molecular orbitals are lower in energy than the original atomic orbitals, while anti-bonding molecular orbitals are higher in energy.
3. The number of molecular orbitals formed is equal to the number of combining atomic orbitals.
4. Electrons fill molecular orbitals according to Hund's rule and the Pauli exclusion principle.
5. The bond order can be calculated using the formula: $(\text{number of electrons in bonding MOs} - \text{number of electrons in anti-bonding MOs})/2$.

Review Questions

• What principle or method is used to construct a molecular orbital diagram?
• How do bonding and anti-bonding molecular orbitals differ in terms of energy?
• Describe how to calculate bond order from a molecular orbital diagram.

Related terms

Bond Order: A measure of bond strength in a molecule, calculated as half the difference between the number of bonding and anti-bonding electrons.

Atomic Orbital: A region around an atom's nucleus where there is a high probability of finding an electron.

Linear Combination of Atomic Orbitals (LCAO): A method for constructing molecular orbitals by combining atomic orbitals from different atoms.