CHEM101: General Chemistry I

In some cases, we can draw more than one equivalent Lewis structure for a given molecule or polyatomic ion. These equivalent structures are called resonance structures. The true structure of these types of molecules or polyatomic ions are actually a hybrid, or mixture, of the resonance structures. This is called a resonance hybrid.

Watch these videos, which introduce resonance structures with the example of the nitrate, Na^3- ion, which has three resonance structures. All three structures are equivalent – they only differ by the placement of the double bond.