Image of benzene molecule, C6H6

Image of benzene molecule which contains six carbon atoms arranged in a ring or hexagon. Each carbon atom (black) is attached by a single bond to a hydrogen atom (green) and to its two closest neighbours. The remaining bond (carbon can make four single bonds) is delocalised (i.e. spread around the aromatic ring). The pi electrons which form these bonds (transparent red donut shapes) exist above and below the plane of the carbons.