Double and Triple Bonds

• When two electron pairs are shared between two atoms, the resulting bond is a double bond. In general, double bonds are shorter and stronger than single bonds. For example, the distance between oxygen nuclei in an oxygen–oxygen double bond is 121 pm. In a single bond, it is 148 pm.
• While Lewis theory does correctly predict a double bond for O2, it is insufficient to explain the paramagnetic properties of oxygen. This problem led to the development of other bonding theories.