Describe the structure of benzene, and how this affects its stability.

Benzene has the molecular formula C₆H₆, with the 6 carbon atoms forming a planar hexagonal ring of C-C sigma bonds. The six hydrogen atoms, one attached to each carbon atom via a C-H sigma bond, protrude from this ring in the same plane. Each carbon atom also has one pi electron and these electrons are delocalised all around the ring, above and below the plane. This delocalisation, referred to as aromaticity, means that all C-C bond lengths in the ring are the same and also gives benzene a high level of chemical and thermal stability.