Resonance: one molecule, several drawings
When several Lewis structures contribute to describing the same species, the real molecule does not flip between drawings. The electronic structure is delocalized.
Core idea
When several Lewis structures contribute to describing the same species, the real molecule does not flip between drawings. The electronic structure is delocalized.
Example
The carbonate ion CO₃²⁻ is a good example: all three C–O bonds are equivalent in the real structure even though a single Lewis drawing cannot show this directly.
Common trap
A formula or trend is useful only when its definition and conditions of use are clear.
Check yourself
Explain the phenomenon in your own words, then identify which quantity or mechanism you would use to quantify it.
The carbonate ion CO₃²⁻ is a good example: all three C–O bonds are equivalent in the real structure even though a single Lewis drawing cannot show this directly.