Benzene does not decolourise bromine water, showing it does not undergo electrophilic addition reactions as the delocalised pi structure is very stable. All of the carbon-carbon bond lengths are the same; the length is intermediate between those expected for carbon-carbon single bonds and carbon-carbon double bonds, showing the electrons are delocalised around the ring.Thermochemically benzene is more stable than the theoretical molecule of cyclohexa-1,3,5-triene due to the added aromatic stability produced by the delocalisation of electrons.