Graphite (left) and diamond (right), two allotropes of carbon
|Standard atomic weight Ar, std(C)||[12.0096, 12.0116] conventional: 12.011|
|Carbon in the periodic table|
|Atomic number (Z)||6|
|Group||group 14 (carbon group)|
|Element categories||, sometimes considered a metalloid|
|Electron configuration||[He] 2s2 2p2|
|Electrons per shell||2, 4|
|Phase at STP||solid|
|Sublimation point||3915 K (3642 °C, 6588 °F)|
|Density (near r.t.)||amorphous: 1.8–2.1 g/cm3 |
graphite: 2.267 g/cm3
diamond: 3.515 g/cm3
|Triple point||4600 K, 10,800 kPa|
|Heat of fusion||graphite: 117 kJ/mol|
|Molar heat capacity||graphite: 8.517 J/(mol·K) |
diamond: 6.155 J/(mol·K)
|Oxidation states||−4, −3, −2, −1, 0, +1, +2, +3, +4 (a mildly acidic oxide)|
|Electronegativity||Pauling scale: 2.55|
|Covalent radius||sp3: 77 pm|
sp2: 73 pm
sp: 69 pm
|Van der Waals radius||170 pm|
|Spectral lines of carbon|
|Crystal structure||graphite: simple hexagonal|
|Crystal structure||diamond: face-centered diamond-cubic|
|Speed of sound thin rod||diamond: 18,350 m/s (at 20 °C)|
|Thermal expansion||diamond: 0.8 µm/(m·K) (at 25 °C)|
|Thermal conductivity||graphite: 119–165 W/(m·K) |
diamond: 900–2300 W/(m·K)
|Electrical resistivity||graphite: 7.837 µΩ·m|
|Magnetic susceptibility||−5.9·10−6 (graph.) cm3/mol|
|Young's modulus||diamond: 1050 GPa|
|Shear modulus||diamond: 478 GPa|
|Bulk modulus||diamond: 442 GPa|
|Poisson ratio||diamond: 0.1|
|Mohs hardness||graphite: 1–2 |
|Discovery||Egyptians and Sumerians (3750 BCE)|
|Recognized as an element by||Antoine Lavoisier (1789)|
|Main isotopes of carbon|
Carbon is a very important chemical element, with a chemical symbol of C. All known life on Earth needs it. Carbon has atomic mass 12 and atomic number 6. It is a nonmetal, meaning that it is not a metal.
Chemistry of carbon[change | change source]
A whole type of Chemistry, organic chemistry, is about carbon and its compounds. Carbon makes many types of compounds. Hydrocarbons are molecules with carbon and hydrogen. Methane, Propane, and many other fuels are hydrocarbons. Many of the substances that people use daily are organic compounds.
Carbon, hydrogen, nitrogen, oxygen, and some other elements like sulfur and phosphorus together form most life on earth (see List of biologically important elements). Carbon forms a very large number of organic compounds because it can form strong bonds with itself and with other elements. Because of the amounts of carbon living things have, all organic things are considered "carbon-based". Each carbon atom can form four single covalent bonds. These bonds allow carbon to form long chain-shaped molecules, called polymers, such as plastics.
Etymology[change | change source]
Types of carbon[change | change source]
Carbon in nature is found in three forms called allotropes: diamond, graphite, and fullerenes. Graphite, with clay, is in pencils. It is very soft. The carbon atoms in it make rings, which are on top of each other and slide very easily. Diamonds are the hardest natural mineral. Fullerenes are a "soccer ball" shape of carbon. They are mostly of interest to science. A special, man-made, tube-shaped allotrope of carbon is the carbon nanotube. Carbon nanotubes are very hard, so they might be used in armor. Nanotubes might be useful in nanotechnology.
There are 10 million known carbon compounds.
Radiocarbon dating[change | change source]
A radioactive isotope of carbon, carbon-14, can be used to figure out how old some objects are or when something died. As long as something is on the surface of the earth and taking in carbon, the amount of carbon-14 stays the same. When an object stops taking in carbon, the carbon-14 amount goes down. Because the half-life (how long it takes for half of a radioactive isotope to go away) of carbon-14 is 5730 years, scientists can see how old the object is by how much carbon-14 is left.
Where carbon is[change | change source]
Carbon is important to the human body and other living things, and it is the second most common element in the human body, at 23% of all body weight. It is also a key part of many biological molecules (molecules used in life).
Most of the carbon on Earth is coal. Graphite is in many (typically desert) areas, including Sri Lanka, Madagascar, and Russia. Diamonds are rare and are found largely in Africa. Carbon is also in some meteorites.
Related pages[change | change source]
References[change | change source]
- Lide, D. R., ed. (2005). CRC Handbook of Chemistry and Physics (86th ed.). Boca Raton (FL): CRC Press. ISBN 0-8493-0486-5.
- Haaland, D (1976). "Graphite-liquid-vapor triple point pressure and the density of liquid carbon". Carbon. 14 (6): 357. doi:10.1016/0008-6223(76)90010-5.
- Savvatimskiy, A (2005). "Measurements of the melting point of graphite and the properties of liquid carbon (a review for 1963–2003)". Carbon. 43 (6): 1115. doi:10.1016/j.carbon.2004.12.027.
- "Fourier Transform Spectroscopy of the Electronic Transition of the Jet-Cooled CCI Free Radical" (PDF). Retrieved 2007-12-06.
- "Fourier Transform Spectroscopy of the System of CP" (PDF). Retrieved 2007-12-06.
- "Carbon: Binary compounds". Retrieved 2007-12-06.
- Properties of diamond, Ioffe Institute Database
- "Material Properties- Misc Materials". www.nde-ed.org. Retrieved 12 November 2016. CS1 maint: discouraged parameter (link)
- Magnetic susceptibility of the elements and inorganic compounds, in Handbook of Chemistry and Physics 81st edition, CRC press.
- Weast, Robert (1984). CRC, Handbook of Chemistry and Physics. Boca Raton, Florida: Chemical Rubber Company Publishing. pp. E110. ISBN 0-8493-0464-4.
- "History of Carbon and Carbon Materials - Center for Applied Energy Research - University of Kentucky". Caer.uky.edu. Retrieved 2008-09-12. CS1 maint: discouraged parameter (link)
- Senese, Fred (2000-09-09). "Who discovered carbon?". Frostburg State University. Retrieved 2007-11-24. CS1 maint: discouraged parameter (link)
- "Fourier Transform Spectroscopy of the System of CP" (PDF). Retrieved 2007-12-06. CS1 maint: discouraged parameter (link)
- "Fourier Transform Spectroscopy of the Electronic Transition of the Jet-Cooled CCI Free Radical" (PDF). Retrieved 2007-12-06. CS1 maint: discouraged parameter (link)
- "Carbon: Binary compounds". Retrieved 2007-12-06. CS1 maint: discouraged parameter (link)
- Emsley, John (2001). Nature's Building blocks. Oxford University Press. ISBN 0-19-850341-5.
- University of Sheffield and Webelements Ltd. (2007). "Chemistry : Periodic Table : carbon : key information".