Carbon-14, or 14C, is a radioactive isotope of carbon discovered February 27, 1940, by Martin Kamen and Sam Ruben. Its nucleus contains 6 protons and 8 neutrons. Its presence in organic materials is used in radiocarbon dating. It occurs naturally and has a relative abundance up to 0.00000000012%. The half-life of carbon-14 is 5730 years. It decays into nitrogen-14 through beta-decay. Carbon-14 is produced in the upper layers of the troposphere and the stratosphere ...

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Including:

Carbon-12 - History

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Prior to 1959 both the IUPAP and IUPAC tended to use used oxygen to define the mole, the chemists defining the mole as the number of atoms of oxygen which had mass 16 g, the physicists using a similar definition but with the oxygen-16 isotope only. The two organizations agreed in 1959/1960 to define the mole as: This was adopted by the CIPM (International Committee for Weights and Measures) in 1967, and in 1971 it was adopted by the 14th CGPM (General Conference on Weights and Measures). In 1980 the CIPM clarified the above definition, defining that the carbon-12 atoms are unbound and ...

See also:

Carbon-12, Carbon-12 - History

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Carbonization is the term for the conversion of an organic substance into carbon or a carbon-containing residue. It is often used in organic chemistry with reference to the generation of coal gas and coal tar from raw coal. Fossil fuels in general are the products of the carbonization of vegetable matter. When biomaterial is exposed to sudden searing heat (as in the case of an atomic bomb explosion or pyroclastic flow from a volcano, for instance), it can be carbonized extremely quickly, turning it into solid carbon. In the destruction of Herculaneum many organic objects such as fur ...

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Carbonation occurs when carbon dioxide is dissolved in water or an aqueous solution. This process is generally represented by the following reaction, where water and gaseous carbon dioxide react to form a dilute solution of carbonic acid. H2O + CO2 ↔ H2CO3 This process yields the "fizz" to carbonated water and sparkling mineral water, the head to beer, and the cor ...

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Carbon is a chemical element in the periodic table that has the symbol C and atomic number 6. An abundant nonmetallic, tetravalent element, carbon has several allotropic forms: Diamond (hardest known natural mineral). Structure: each atom is bonded tetrahedrally to four others, making a 3-dimensional network of puckered six-membered rings of atoms. Graphite (one of the softest substances). Structure: each atom is bonded trigonally to three other atoms, making a 2-dimensional network of flat s ...

Including:

Carbon - Notable characteristics Carbon - Applications
Carbon - Other uses
Carbon - History and Etymology Carbon - Allotropes Carbon - Occurrence Carbon - Organic compounds
Carbon - Carbon chains
Carbon - Carbon cycle Carbon - Isotopes Carbon - Precautions

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Carbonate is an anion with a charge of -2 and an empirical formula of CO32-. For an aqueous solution, carbonate exists in three forms. In strongly basic conditions, the carbonate ion, CO32-, predominates. In weakly basic conditions, bicarbonate ion, HCO3- is prevalent. In acid conditions, aqueous carbon dioxide, CO2(aq), is the main form. This also contains a minute amount of carbonic acid, H2CO3. Thus sodium carbonate is basic, sodium bicarbonate is weakly ba ...

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Carbon has two stable, naturally-occurring isotopes: carbon-12, or 12C, (98.89%) and carbon-13, or 13C, (1.11%), and one unstable, naturally-occurring, radioisotope; carbon-14 or 14C. There are 15 known isotopes of carbon and the shortest-lived of these is 8C which decays through proton emission and alpha decay. It has a half-life of 1.98739x10-21 s. In 1961 the International Union of Pure and Applied Chemistry adopted the isotope carbon-12 as the basis for atomic weights. Carbon-14 has a half-life of 5730 y and has been used extensively for radioca ...

See also:

Carbon, Carbon - Notable characteristics, Carbon - Applications, Carbon - Other uses, Carbon - History and Etymology, Carbon - Allotropes, Carbon - Occurrence, Carbon - Organic compounds, Carbon - Carbon chains, Carbon - Carbon cycle, Carbon - Isotopes, Carbon - Precautions

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The allotropes of carbon are the different molecular configurations (allotropes) that pure carbon can take. These allotropes include: amorphous carbon carbon nanofoam (discovered in 1997) diamond fullerene (which includes buckyballs and carbon nanotubes) graphite lonsdaleite aggregated diamond nanorods The existence of carbyne phases is disputed – see the entry on chaoite for details.

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Carbon flux is an abbreviated phrase used loosly to refer to the net difference between sequestration and respiration of carbon dioxide. Given the accepted definition of what constitutes a flux, a more appropriate name for the annual difference between carbon sequestration and respiration would be "annual atmospheric carbon accumulation rate" or "annual global integrated surface flux of carbon" or "anual global net carbon flux" . Annual net carbon flux has been grossly calculated to be close to zero.[1] That is, emission and absorptio

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Carbonate minerals are those minerals containing the carbonate ion: CO32-. Carbonate minerals - Example carbonates. Carbonate minerals - Anhydrous carbonates. Calcite group: Trigonal Calcite CaCO3 Gaspeite (Ni,Mg,Fe2+)CO3 Magnesite MgCO3 Otavite CdCO3 Rhodochrosite MnCO3 Siderite FeCO3 Smithsonite ZnCO3 ...

Including:

Carbonate minerals - Example carbonates
Carbonate minerals - Anhydrous carbonates Carbonate minerals - Anhydrous carbonates with compound formulas Carbonate minerals - Carbonates with hydroxyl or halogen Carbonate minerals - Hydrated carbonates

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Carbon fixation is a process found in autotrophs, usually driven by photosynthesis, whereby carbon dioxide is converted into organic compounds. In plants, there are three types: C3 - plant that uses the Calvin Cycle for the initial steps that incorporate CO2 into organic matter, forming a 3-carbon compound as the 1st stable intermediate. C4 - plant that prefaces the Calvin Cycle with reactions that incorporate CO2 into 4-carbon compou

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The carbon cycle is the biogeochemical cycle by which carbon is exchanged between the biosphere, geosphere, hydrosphere and atmosphere of the Earth. (Other bodies may have carbon cycles, but little is known about them.) All of these components are reservoirs of carbon. The cycle is usually thought of as four main reservoirs of carbon interconnected by pathways of exchange. The reservoirs are the atmosphere, terrestrial biosphere (usually includes freshwater systems), oceans, and sediments (includes fossil fuels). The annual mov ...

Including:

Carbon cycle - Carbon in the atmosphere Carbon cycle - Carbon in the biosphere Carbon cycle - Carbon cycle modelling

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Carbon nanofoam is the fifth known allotrope of carbon discovered in 1997 by Andrei V. Rode and co-workers at the Australian National University in Canberra. It consists of a low-density cluster-assembly of carbon atoms strung together in a loose three-dimensional web. Each cluster is about 6 nanometers wide and consists of about 4000 carbon atoms linked in graphite-like sheets that are given negative curvature by the inclusion of heptagons among the regular hexagonal pattern. This is the opposite of what happens in the case of buckminsterfullerenes, in which carbon sheets are g ...

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Copper(II) carbonate (often called copper carbonate or cupric carbonate) is a blue-green compound (chemical formula CuCO3) forming most of the patina one sees on weathered brass, bronze, and copper. The color can vary from bright blue to green, because there may be a mixture of both copper carbonate and basic copper carbonate in various stages of hydration. It was formerly much used as a pigment, and is still in use for artist's colours. When powdered, it is a fire hazard. It is also been used in some types of make-up, like lipst ...

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Carbonic acid is a carbon-containing acid with the formula H2CO3. It is also a name sometimes given to solutions of carbon dioxide in water, which contain small amounts of H2CO3. The salts of carbonic acids are called bicarbonates (or hydrogencarbonates) and carbonates. Carbon dioxide dissolved in water is in equilibrium with carbonic acid: CO2 + H2 ...

Including:

Carbonic acid - Acidity of carbonic acid Carbonic acid - Instability of carbonic acid Carbonic acid - Carbonic acid and rain water

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Carbon Sequestering is a process whereby trees and other plants remove carbon dioxide from the atmosphere and through photosynthesis, turn it into plant material. Recent, some have proposed the sequestering of carbon-dioxide by capturing the exhaust from a fossil fuel combustion and pumping it back into earth. The increase in pressure can be used to enhance the extraction of additional fossil fuel in nearbby wells. This is sometimes referred to as "resequestration". There is much concern however that the carbon will not remain captive, and would leak bac ...

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Carbon fiber can refer to carbon filament thread, or to felt or woven cloth made from those carbon filaments. By extension, it is also used informally to mean any composite material made with carbon filament; for more on that application, see graphite-reinforced plastic. Carbon fiber - Synthesis. Each carbon filament is made out of long, thin sheets of carbon similar to graphite. A common method of making carbon filaments is the oxidation and thermal pyrolysis of polyacrylonitrile (PAN), a polymer used in t ...

Including:

Carbon fiber - Synthesis Carbon fiber - Textile Carbon fiber - Uses Carbon fiber - Future Directions

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Carbon nanotubes are cylindrical carbon molecules with novel properties that make them potentially useful in a wide variety of applications (e.g., nano-electronics, optics, materials applications, etc.). They exhibit extraordinary strength and unique electrical properties, and are efficient conductors of heat. Inorganic nanotubes have also been synthesized. A nanotube (also known as a buckytube) is a member of the fullerene structural family, which also includes buckyballs. Whereas buckyballs are spherical in shape, a nanotube ...

Including:

Carbon nanotube - Single-walled nanotubes Carbon nanotube - Properties Carbon nanotube - Synthesis Carbon nanotube - Applications Carbon nanotube - Carbon nanotube fiber & film Carbon nanotube - Current progress Carbon nanotube - Carbon nanotubes in electrical circuits

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Amorphous carbon is the name used for carbon that does not have any crystalline structure. As with all glassy materials, some short-range order can be observed, but there is no long-range pattern of atomic positions. While entirely amorphous carbon can be made, most of the material described as "amorphous" actually contains crystallites of graphite [1] or diamond [2] with varying amounts of amorphous carbon holding them together, making them technically polycrystalline or nanocrystalline materials. Commercial carbon also usually contains significant quantities of ...

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