Molecular orbital theory is a model in chemistry that explains how atoms bond to form molecules. It suggests that when atoms combine, their atomic orbitals merge to create new orbitals called molecular orbitals. These orbitals can be occupied by electrons, which helps determine the stability and properties of the resulting molecule. In this theory, molecular orbitals are classified as bonding or antibonding. Bonding orbitals stabilize the molecule by allowing electrons to be shared between atoms, while antibonding orbitals can destabilize it if occupied. This framework helps predict molecular shapes, bond lengths, and other important characteristics of compounds.