ABSTRACT
Carbon is a unique element. The carbon atom has the unusual property of forming strong covalent bonds to other carbon atoms. This underlies organic chemistry, which is based on the formation of chain and ring structures of linked carbon atoms. Many biomolecules are complex organic molecules that are present in all living organisms. A second group of carbon compounds forms simple structures, usually with only one carbon atom. They are important components of the mineral world, the sea, and the atmosphere. Organisms use these substances as a carbon resource. The two areas of carbon chemistry are linked in the natural environment by the carbon cycle.
