Why the benzene structure should be dawin with a circle inside ?
Whilst it is common to represent a chemical structure in a consistent and recognisable way, often the structural formula shown does not adequately represent the distribution of electrons within it. Rather, it is necessary to represent the molecule (or ion) by various alternative structures, with the true structure, and its distribution of electrons, lying somewhere between the extremesThe benzene molecule is often represented as a hexagonal ring of alternate single and double carbon-carbon bonds. But, given one such structure drawn on paper, the single and double bonds can be shown to have changed positions simply by re-distributing the pairs of electrons. The different structures contributing to the resonance hybrid are referred to as CANONICAL FORMS of the molecule. The more stable a canonical form, the more it contributes to the resonance hybrid. The resonance hybrid is more stable than any one of its canonical forms, and the difference in energy between the resonance hybrid and the
