(From the Latin carbo, coal) A nonmetallic chemical element found in many inorganic compounds and all organic compounds. It exists freely as pure carbon in diamond and graphite and as the basic element in coal, coke, charcoal, soot, etc. Carbon is also useful as a neutron moderator, as in a nuclear reactor.

Symbol: C
Atomic number: 6
Atomic weight: 12.0107
Density (at room temperature and pressure): 2.3 g/cc (graphite); 3.513 (diamond)
Melting point: 3,550°C
Boiling point: 4,827°C
Main valence: -4, +2, +4
Ground state electron configuration: [He]2s22p2

See also: carbon-14