|1.||a. a nonmetallic element existing in the three crystalline forms: graphite, diamond, and buckminsterfullerene: occurring in carbon dioxide, coal, oil, and all organic compounds. The isotope carbon-12 has been adopted as the standard for atomic wt; carbon-14, a radioisotope with a half-life of 5700 years, is used in radiocarbon dating and as a tracer. Symbol: C; atomic no: 6; atomic wt: 12.011; valency: 2, 3, or 4; relative density: 1.8--2.1 (amorphous), 1.9--2.3 (graphite), 3.15--3.53 (diamond); sublimes at 3367±25°C; boiling pt: 4827°C|
|b. (as modifier): a carbon compound|
|2.||carbon paper short for carbon copy|
|3.||a carbon electrode used in a carbon-arc light or in carbon-arc welding|
|4.||a rod or plate, made of carbon, used in some types of battery|
|[C18: from French carbone, from Latin carbō charcoal, dead or glowing coal]|
carbon car·bon (kär'bən)
A nonmetallic element occuring in many inorganic and in all organic compounds, existing as graphite and diamond and as a constituent of coal, limestone, and petroleum, and capable of chemical self-bonding to form a number of important molecules. Atomic number 6; atomic weight 12.01115; sublimation point above 3,500°C; melting point 3,550°C; specific gravity of amorphous carbon 1.8 to 2.1, of diamond 3.15 to 3.53, of graphite 1.9 to 2.3; valence 2, 3, 4.
|carbon (kär'bən) Pronunciation Key
A naturally abundant, nonmetallic element that occurs in all organic compounds and can be found in all known forms of life. Diamonds and graphite are pure forms, and carbon is a major constituent of coal, petroleum, and natural gas. Carbon generally forms four covalent bonds with other atoms in larger molecules. Atomic number 6; atomic weight 12.011; sublimation point above 3,500°C; boiling point 4,827°C; specific gravity of amorphous carbon 1.8 to 2.1, of diamond 3.15 to 3.53, of graphite 1.9 to 2.3; valence 2, 3, 4. See Periodic Table.