A resonance hybrid is the actual structure of a molecule or ion, regarded as a blend of all its contributing resonance forms rather than any one of them. The bonding is spread out, or delocalised, over the structure, which lowers the energy and increases stability. In the carbonate ion, for example, the three C–O bonds are identical, a feature only the resonance hybrid can express.

共振杂化体是分子或离子的实际结构,被视为其全部贡献共振式的混合,而非其中任何单一形式。其成键分布开来,即离域于整个结构之上,从而降低能量、提高稳定性。例如在碳酸根离子中,三个 C–O 键完全相同,这一特征只有共振杂化体才能表达。