What is resonance Theory?
Answers
theory of resonance, in chemistry, theory by which the actual normal state of a molecule is represented not by a single valence-bond structure but by a combination of several alternative distinct structures.
The molecule is then said to resonate among the several valence-bond structures or to have a structure that is a resonance hybrid of these structures.
The energy calculated for a resonance hybrid is lower than the energies of any of the alternative structures; the molecule is then said to be stabilized by resonance. The difference between the energies of any one of the alternative structures and the energy of the resonance hybrid is designated resonance energy.
*The theory of resonance is based on the fundamental principle of quantum mechanics, which states that the wave function representing a stationary state of a system can be expressed as a weighted sum of the wave functions that correspond to several hypothetical structures for the system and that the proper combination is that sum which leads to a minimum calculated energy for the system.
