Answer:
resonance
Step-by-step explanation:
Resonance is the phenomenon that explains the bonding in the certain molecules or the ions by combination of different contributing structures into the resonance hybrid.
Resonance structures are the set of two or more than two Lewis Structures which collectively describe bonding of the molecule by using fractional bonds and fractional charges.
Consider the case of benzene, in which there are three double bonds and three single bonds but the actual bond length of the C-C bond in benzene is in between single and double bond. This is because of resonance.