Why Carbon Is Special

Carbon's extraordinary variety comes mainly from two properties: Tetravalency + Catenation Tetravalency means that carbon normally forms four covalent bonds. Catenation means that carbon atoms can bond with one another to produce chains and rings. Carbon can also form C–C, C=C and C≡C bonds. These properties form the foundation of organic chemistry.

Carbon is special because one carbon atom can make four bonds. It can also join with other carbon atoms. So carbon can build long chains, branches, rings, small molecules and very large molecules. That is why there are so many carbon compounds.

Carbon is tetravalent and shows strong catenation. It forms stable covalent bonds with itself and with elements such as H, O, N and halogens. Carbon can also form single, double and triple bonds, producing a very large number of molecular structures.

Carbon's chemical diversity results from a combination of tetravalency, relatively strong carbon-carbon bonding, catenation, multiple-bond formation and bonding with many heteroatoms. Different carbon skeletons and functional groups produce structural diversity and different chemical reactivities. These properties explain why carbon chemistry forms a major independent branch of chemistry.

Carbon has atomic number 6 · Carbon normally forms four covalent bonds · Tetravalency = four-bond capacity · Catenation = carbon bonding with carbon · Carbon forms chains and rings · Carbon forms single, double and triple bonds · Functional groups increase chemical variety