NationMaster - Encyclopedia: Carbon

Carbon (pronounced /kɑɹbən/) is a chemical element with the symbol C and atomic number 6. It is a group 14, nonmetallic, tetravalent element, that presents several allotropic forms of which the best known are graphite (the thermodynamically stable form under normal conditions), diamond, and amorphous carbon.^[7] There are three naturally occurring isotopes: ¹²C and ¹³C are stable, and ¹⁴C is radioactive, decaying with a half-life of about 5700 years.^[8] Carbon is one of the few elements known to man since antiquity.^[9]^[10] The name "carbon" comes from Latin language carbo, coal, and in some Romance languages, the word carbon can refer both to the element and to coal. Carbon 12 is a stable isotope of the element carbon. ... Carbon 12 is a stable isotope of the element carbon. ... Carbon 12 is a stable isotope of the element carbon. ... Carbon 12 is a stable isotope of the element carbon. ... Stable isotopes are chemical isotopes that are not radioactive. ... This article or section does not adequately cite its references or sources. ... Carbon-13 is a stable isotope of carbon. ... Carbon-13 is a stable isotope of carbon. ... Carbon-13 is a stable isotope of carbon. ... Carbon-13 is a stable isotope of carbon. ... Stable isotopes are chemical isotopes that are not radioactive. ... This article or section does not adequately cite its references or sources. ... Carbon-14 is the radioactive isotope of carbon discovered February 27, 1940, by Martin Kamen and Sam Ruben. ... Carbon-14 is the radioactive isotope of carbon discovered February 27, 1940, by Martin Kamen and Sam Ruben. ... A trace radioisotope is a radioisotope that is naturally occurring. ... A year (from Old English gÄ“r) is the time between two recurrences of an event related to the orbit of the Earth around the Sun. ... In nuclear physics, beta decay (sometimes called neutron decay) is a type of radioactive decay in which a beta particle (an electron or a positron) is emitted. ... General Name, symbol, number nitrogen, N, 7 Chemical series nonmetals Group, period, block 15, 2, p Appearance colorless gas Standard atomic weight 14. ... Recommended values for many properties of the elements, together with various references, are collected on these data pages. ... The periodic table of the chemical elements A chemical element, or element, is a type of atom that is distinguished by its atomic number; that is, by the number of protons in its nucleus. ... See also: List of elements by atomic number In chemistry and physics, the atomic number (also known as the proton number) is the number of protons found in the nucleus of an atom. ... Together with the metals and metalloids, a nonmetal is one of three categories of chemical elements as distinguished by ionization and bonding properties. ... In chemistry, a tetravalence is the state of an atom with four electrons available for covalent chemical bonding in its valence (outermost electron shell). ... Eight allotropes of carbon: a) Diamond, b) Graphite, c) Lonsdaleite, d) C60 (Buckminsterfullerene or buckyball), e) C540, f) C70, g) Amorphous carbon, and h) single-walled carbon nanotube or buckytube. ... For other uses, see Graphite (disambiguation). ... In thermodynamics, a thermodynamic system is said to be in thermodynamic equilibrium when it is in thermal equilibrium, mechanical equilibrium, and chemical equilibrium. ... This article is about the mineral. ... Amorphous carbon is the name used for carbon that does not have any crystalline structure. ... Isotopes are atoms of a chemical element whose nuclei have the same atomic number, Z, but different atomic weights, A. The word isotope, meaning at the same place, comes from the fact that isotopes are located at the same place on the periodic table. ... Carbon 12 is a stable isotope of the element carbon. ... Carbon-13 is a stable isotope of carbon. ... Carbon-14 is the radioactive isotope of carbon discovered February 27, 1940, by Martin Kamen and Sam Ruben. ... Radioactive decay is the set of various processes by which unstable atomic nuclei (nuclides) emit subatomic particles. ... Half-Life For a quantity subject to exponential decay, the half-life is the time required for the quantity to fall to half of its initial value. ... The discovery of the elements known to exist today is presented here in chronological order. ... Latin was the language originally spoken in the region around Rome called Latium. ... Coal Example chemical structure of coal Coal is a fossil fuel formed in ecosystems where plant remains were saved by water and mud from oxidization and biodegradation. ... The Romance languages (sometimes referred to as Romanic languages) are a branch of the Indo-European language family that comprises all the languages that descend from Latin, the language of the Roman Empire. ...

It is the fourth most abundant element in the universe by mass after hydrogen, helium, and oxygen. It is present in all known lifeforms, and in the human body it is the second most abundant element by mass (about 18.5%) after oxygen.^[11] This abundance, together with the unique diversity of organic compounds and their unusual polymer-forming ability at the temperatures commonly encountered on Earth, make this element the chemical basis of all known life. The abundance of a chemical element measures how relatively common the element is, or how much of the element there is by comparison to all other elements. ... This article is about the chemistry of hydrogen. ... General Name, symbol, number helium, He, 2 Chemical series noble gases Group, period, block 18, 1, s Appearance colorless Standard atomic weight 4. ... This article is about the chemical element and its most stable form, or dioxygen. ... This article is about life in general. ... An organic compound is any of a large class of chemical compounds whose molecules contain carbon, with exception of carbides, carbonates and carbon oxides. ... This article is about Earth as a planet. ... This article is about life in general. ...

The physical properties of carbon vary widely with the allotropic form. For example, diamond is highly transparent, while graphite is opaque and black. Diamond is among the hardest materials known, while graphite is soft enough to form a streak on paper. Diamond has a very low electric conductivity, while graphite is a very good conductor. Also, diamond has the highest thermal conductivity of all known materials under normal conditions. All the allotropic forms are solids under normal conditions. 1) A physical property is an aspect of an object that can be experienced using one of the five human senses: touch, taste, smell, sight or sound, or, in an extended sense, detected through any measuring device. ... Transparent glass ball In optics, transparency is the property of allowing light to pass. ... A substance or object that is opaque is neither transparent nor translucent. ... In science and engineering, conductors, such as copper or aluminum, are materials with atoms having loosely held valence electrons. ... K value redirects here. ... In physics, thermal conductivity, k, is the intensive property of a material that indicates its ability to conduct heat. ...

All forms of carbon are highly stable, requiring high temperature to react even with oxygen. The most common oxidation state of carbon in inorganic compounds is +4, while +2 is found in carbon monoxide and other transition metal carbonyl complexes. The largest sources of inorganic carbon are limestones, dolomites and carbon dioxide, but significant quantities occur in organic deposits of coal, peat, oil and methane clathrates. Carbon forms more compounds than any other element, with almost ten million pure organic compounds described to date, which in turn are a tiny fraction of such compounds that are theoretically possible under standard conditions.^[12] In chemistry, the oxidation state is an indicator of the degree of oxidation of an atom in a chemical compound. ... An inorganic compound is a chemical compound not containing carbon and hydrogen atoms bonded to each other. ... Carbon monoxide, with the chemical formula CO, is a colorless, odorless, and tasteless gas. ... In chemistry, the term transition metal (sometimes also called a transition element) has two possible meanings: It commonly refers to any element in the d-block of the periodic table, including zinc, cadmium and mercury. ... Carbonyl group In organic chemistry, a carbonyl group is a functional group composed of a carbon atom double-bonded to an oxygen atom : C=O. The term carbonyl can also refer to carbon monoxide as a ligand in an inorganic or organometallic complex (a metal carbonyl, e. ... For other uses, see Limestone (disambiguation). ... For other uses, see Dolomite (disambiguation). ... Carbon dioxide (chemical formula: ) is a chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom. ... Coal Example chemical structure of coal Coal is a fossil fuel formed in ecosystems where plant remains were saved by water and mud from oxidization and biodegradation. ... Peat in Lewis, Scotland Peat is an accumulation of partially decayed vegetation matter. ... Synthetic motor oil being poured. ... Burning ice. Methane, released by heating, burns; water drips (USGS). ... Look up chemical compound in Wiktionary, the free dictionary. ... Benzene is the simplest of the arenes, a family of organic compounds An organic compound is any member of a large class of chemical compounds whose molecules contain carbon. ...

1 Characteristics
2 Compounds
- 2.1 Inorganic compounds
- 2.2 Organic compounds
3 History and etymology
- 3.1 Applications
4 Production
- 4.1 Graphite Production
5 Precautions
6 See also
7 References
8 External links

Characteristics

Carbon exhibits remarkable properties, some paradoxical. Its different forms or allotropes (see below) include the hardest naturally occurring substance (diamond) and also one of the softest substances (graphite) known. Moreover, it has a great affinity for bonding with other small atoms, including other carbon atoms, and is capable of forming multiple stable covalent bonds with such atoms. Because of these properties, carbon is known to form nearly ten million different compounds, the large majority of all chemical compounds.^[12] Moreover, carbon has the highest melting/sublimation point of all elements.^{[citation needed]} At atmospheric pressure it has no actual melting point as its triple point is at 10 MPa (100 bar) so it sublimates above 4000 K.^{[citation needed]} Carbon sublimes in a carbon arc which has a temperature of about 5800K. Thus irrespective of its allotropic form, carbon remains solid at higher temperatures than the highest melting point metals such as tungsten or rhenium. Although thermodynamically prone to oxidation, carbon resists oxidation more effectively than elements such as iron and copper that are weaker reducing agents at room temperature. Allotropy (Gr. ... This article is about the mineral. ... For other uses, see Graphite (disambiguation). ... A chemical bond is the physical process responsible for the attractive interactions between atoms and molecules, and that which confers stability to diatomic and polyatomic chemical compounds. ... For other uses, see Atom (disambiguation). ... Covalent bonding is a form of chemical bonding characterized by the sharing of one or more pairs of electrons between atoms, in order to produce a mutual attraction, which holds the resultant molecule together. ... A chemical compound is a chemical substance formed from two or more elements, with a fixed ratio determining the composition. ... The melting point of a solid is the temperature range at which it changes state from solid to liquid. ... This article does not cite any references or sources. ... Atmospheric pressure is the pressure at any given point in the Earths atmosphere. ... In physics, the triple point of a substance is the temperature and pressure at which three phases (gas, liquid, and solid) of that substance may coexist in thermodynamic equilibrium. ... The bar (symbol bar), decibar (symbol dbar) and the millibar (symbol mbar, also mb) are units of pressure. ... For other uses, see Tungsten (disambiguation). ... General Name, Symbol, Number rhenium, Re, 75 Chemical series transition metals Group, Period, Block 7, 6, d Appearance grayish white Standard atomic weight 186. ...

Diamond and graphite are two allotropes of carbon: pure forms of the same element that differ in structure.

Carbon compounds form the basis of all life on Earth and the carbon-nitrogen cycle provides some of the energy produced by the Sun and other stars. Although it forms an extraordinary variety of compounds, most forms of carbon are comparatively unreactive under normal conditions. At standard temperature and pressure, it resists all but the strongest oxidizers. It does not react with sulfuric acid, hydrochloric acid, chlorine or any alkalis. At elevated temperatures carbon reacts with oxygen to form carbon oxides, and will reduce such metal oxides as iron oxide to the metal. This exothermic reaction is used in the iron and steel industry to control the carbon content of steel:
Fe₃O₄ + 4C_(s) → 3Fe_(s) + 4CO_(g)
with sulfur to form carbon disulfide and with steam in the coal-gas reaction
C_(s) + H₂O_(g) → CO_(g) + H_2(g).
Carbon combines with some metals at high temperatures to form metallic carbides, such as the iron carbide cementite in steel, and tungsten carbide, widely used as an abrasive and for making hard tips for cutting tools. Image File history File links Size of this preview: 627 Ã— 600 pixelsFull resolution (1206 Ã— 1154 pixel, file size: 164 KB, MIME type: image/jpeg) This file is a composite of Image:GraphiteUSGOV.jpg (public domain), en:Image:Brillanten. ... Image File history File links Size of this preview: 627 Ã— 600 pixelsFull resolution (1206 Ã— 1154 pixel, file size: 164 KB, MIME type: image/jpeg) This file is a composite of Image:GraphiteUSGOV.jpg (public domain), en:Image:Brillanten. ... This article is about Earth as a planet. ... The CNO (carbon-nitrogen_oxygen) cycle is one of two fusion reactions by which stars convert hydrogen to helium, the other being the proton-proton chain. ... Sol redirects here. ... This article is about the astronomical object. ... Sulfuric acid, (also known as sulphuric acid) H2SO4, is a strong mineral acid. ... Hydrochloric acid is the aqueous solution of hydrogen chloride gas (HCl). ... General Name, symbol, number chlorine, Cl, 17 Chemical series nonmetals Group, period, block 17, 3, p Appearance yellowish green Standard atomic weight 35. ... In thermodynamics, the word exothermic outside heating describes a process or reaction that releases energy usually in the form of heat, but it can also release energy in form of light (e. ... This article is about the chemical element. ... CS2 redirects here. ... Cementite or iron carbide is a chemical compound with the formula Fe3C, and an orthorhombic crystal structure. ... Monotungsten carbide, WC, or Ditungsten Carbide, W2C, is a chemical compound containing tungsten and carbon, similar to titanium carbide. ... An abrasive is a material, often a mineral, that is used to shape or finish (see metal polishing and wood finishing) a workpiece through rubbing which leads to part of the workpiece being worn away. ...

The system of carbon allotropes spans a range of extremes:

Synthetic diamond nanorods are the hardest materials known.	Graphite is one of the softest materials known.
Diamond is the ultimate abrasive.	Graphite is a very good lubricant.
Diamond is an excellent electrical insulator.	Graphite is a conductor of electricity.
Diamond is the best known thermal conductor	Some forms of graphite are used for thermal insulation (i.e. firebreaks and heatshields)
Diamond is highly transparent.	Graphite is opaque.
Diamond crystallizes in the cubic system.	Graphite crystallizes in the hexagonal system.
Amorphous carbon is completely isotropic.	Carbon nanotubes are among the most anisotropic materials ever produced.

An abrasive is a material, often a mineral, that is used to shape or finish (see metal polishing and wood finishing) a workpiece through rubbing which leads to part of the workpiece being worn away. ... A lubricant (colloquially, lube) is a substance (often a liquid) introduced between two moving surfaces to reduce the friction and wear between them. ... For other uses, see insulation. ... In science and engineering, conductors, such as copper or aluminum, are materials with atoms having loosely held valence electrons. ... In physics, thermal conductivity, k, is the intensive property of a material that indicates its ability to conduct heat. ... Wikimedia Commons has media related to: Thermal insulation Thermal insulation on the Huygens probe Rockwool Insulation, 1600 dpi scan against the grain Rockwool Insulation, 1600 dpi scan with the grain The term thermal insulation can refer to materials used to reduce the rate of heat transfer, or the methods and... A substance or object that is opaque is neither transparent nor translucent. ... In crystallography, the cubic crystal system (or isometric crystal system) is the most symmetric of the 7 crystal systems. ... In crystallography, the hexagonal crystal system is one of the 7 lattice point groups. ... Isotropic means independent of direction. Isotropic radiation has the same intensity regardless of the direction of measurement, and an isotropic field exerts the same action regardless of how the test particle is oriented. ... This article is being considered for deletion in accordance with Wikipedias deletion policy. ...

Allotropes

Main article: Allotropes of carbon

Atomic carbon is a very short-lived specie and therefore, carbon is stabilized in various multi-atomic structures with different molecular configurations called allotropes. The three relatively well-known allotropes of carbon are amorphous carbon, graphite, and diamond. Once considered exotic, fullerenes are nowadays commonly synthesized and used in research; they include buckyballs,^[13]^[14] carbon nanotubes,^[15] carbon nanobuds^[16] and nanofibers,^[17].^[18] Several other exotic allotropes have also been discovered, such as aggregated diamond nanorods,^[19] lonsdaleite,^[20] glassy carbon,^[21] carbon nanofoam^[22] and linear acetylenic carbon.^[23] Eight allotropes of carbon: a) Diamond, b) Graphite, c) Lonsdaleite, d) C60 (Buckminsterfullerene or buckyball), e) C540, f) C70, g) Amorphous carbon, and h) single-walled carbon nanotube or buckytube. ... Making atomic carbon :C: - The source of light is the electrical arcing between two carbon rods. ... Allotropy (Gr. ... Amorphous carbon is the name used for carbon that does not have any crystalline structure. ... For other uses, see Graphite (disambiguation). ... This article is about the mineral. ... The Icosahedral Fullerene C540 C60 and C-60 redirect here. ... Buckminsterfullerene (C60) Fullerenes are molecules composed entirely of carbon, taking the form of a hollow sphere, ellipsoid, or tube. ... // 3D model of three types of single-walled carbon nanotubes. ... Computer models of several stable NanoBud structures In nanotechnology, carbon NanoBuds are a newly discovered material combining two previously discovered allotropes of carbon: carbon nanotubes and fullerenes. ... Carbon nanofibers Carbon nanofibers are cylindric nanostructures with graphene layers arranged as stacked cones, cups or plates. ... Aggregated diamond nanorods, or ADNRs, are an allotrope of carbon believed to be the hardest and least compressible known material, as measured by its isothermal bulk modulus; aggregated diamond nanorods have a modulus of 491 gigapascals (GPa), while a conventional diamond has a modulus of 442 GPa. ... Lonsdaleite is a hexagonal allotrope of the carbon allotrope diamond, believed to form when meteoric graphite falls to Earth. ... Glassy carbon is a class of non-graphitizing carbon which is widely used as an electrode material in electrochemistry, as well as for high temperature crucibles and as a component of some prosthetic devices. ... 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. ...

The amorphous form, is an assortment of carbon atoms in a non-crystalline, irregular, glassy state, which is essentially graphite but not held in a crystalline macrostructure. It is present as a powder, and is the main constituent of substances such as charcoal, lampblack (soot) and activated carbon.

At normal pressures carbon takes the form of graphite, in which each atom is bonded trigonally to three others in a plane composed of fused hexagonal rings, just like those in aromatic hydrocarbons. The resulting network is 2-dimensional, and the resulting flat sheets are stacked and loosely bonded through weak Van der Waals forces. This gives graphite its softness and its cleaving properties (the sheets slip easily past one another). Because of the delocalization of one of the outer electrons of each atom to form a π-cloud, graphite conducts electricity, but only in the plane of each covalently bonded sheet. This results in a lower bulk electrical conductivity for carbon than for most metals. The delocalization also accounts for the energetic stability of graphite over diamond at room temperature.

Some allotropes of carbon: a) diamond; b) graphite; c) lonsdaleite; d-f) fullerenes (C60, C540, C70); g) amorphous carbon; h) carbon nanotube.

At very high pressures carbon forms the more compact allotrope diamond, having nearly twice the density of graphite. Here, each atom is bonded tetrahedrally to four others, thus making a 3-dimensional network of puckered six-membered rings of atoms. Diamond has the same cubic structure as silicon and germanium and, thanks to the strength of the carbon-carbon bonds is the hardest naturally occurring substance in terms of resistance to scratching. Contrary to the popular belief that "diamonds are forever", they are in fact thermodynamically unstable under normal conditions and transform into graphite.^[7] But due to a high activation energy barrier, the transition into graphite is so extremely slow at room temperature as to be unnoticeable. Under some conditions, carbon crystallizes as Lonsdaleite, a form similar to diamond but forming a hexagonal crystal lattice.^[20]

Fullerenes have a graphite-like structure, but instead of purely hexagonal packing, they also contain pentagons (or even heptagons) of carbon atoms, which bend the sheet into spheres, ellipses or cylinders. The properties of fullerenes (split into buckyballs, buckytubes and nanobuds) have not yet been fully analyzed and represents an intense area of research in nanomaterials. The name "fullerene" is given after Richard Buckminster Fuller, developer of some geodesic domes,^{[citation needed]} which resemble the structure of fullerenes. The buckyballs are fairly large molecules formed completely of carbon bonded trigonally, forming spheroids (the best-known and simplest is the soccerball-shaped structure C₆₀ buckminsterfullerene).^[13] Carbon nanotubes are structurally similar to buckyballs, except that each atom is bonded trigonally in a curved sheet that forms a hollow cylinder.^[14]^[15] Nanobuds were first published in 2007 and are hybrid bucky tube/buckyball materials (buckyballs are covalently bonded to the outer wall of a nanotube) that combine the properties of both in a single structure.^[16]

Of the other discovered allotropes, aggregated diamond nanorods have been synthesised in 2005 and are believed to be the hardest substance known yet.^[24] Carbon nanofoam is a ferromagnetic allotrope discovered in 1997. It consists of a low-density cluster-assembly of carbon atoms strung together in a loose three-dimensional web, in which the atoms are bonded trigonally in six- and seven-membered rings. It is among the lightest known solids, with a density of about 2 kg/m³.^[25] Similarly, glassy carbon contains a high proportion of closed porosity.^[21] But unlike normal graphite, the graphitic layers are not stacked like pages in a book, but have a more random arrangement. Linear acetylenic carbon^[23] has the chemical structure^[26] -(C:::C)_n- .Carbon in this modification is linear with sp orbital hybridisation, and is a polymer with alternating single and triple bonds. This type of carbyne is of considerable interest to nanotechnology as its Young's modulus is forty times that of the hardest known material - diamond.^[27]

An amorphous solid is a solid in which there is no long-range order of the positions of the atoms. ... For other uses, see Graphite (disambiguation). ... Charcoal is the blackish residue consisting of impure carbon obtained by removing water and other volatile constituents from animal and vegetation substances. ... Soot, also called lampblack or carbon black, is a dark powdery deposit of unburned fuel residues, usually composed mainly of amorphous carbon, that accumulates in chimneys, automobile mufflers and other surfaces exposed to smoke—especially from the combustion of carbon-rich organic fuels in the lack of sufficient oxygen. ... Soot, also called lampblack, Pigment Black 7, carbon black or black carbon, is a dark powdery deposit of unburned fuel residues, usually composed mainly of amorphous carbon, that accumulates in chimneys, automobile mufflers and other surfaces exposed to smokeâ€”especially from the combustion of carbon-rich organic fuels in the... Activated carbon Activated carbon, also called activated charcoal or activated coal, is a general term which covers carbon material mostly derived from charcoal. ... For other uses, see Graphite (disambiguation). ... For other uses, see Hexagon (disambiguation). ... An aromatic hydrocarbon (abbreviated as AH) or arene [1] is a hydrocarbon, the molecular structure of which incorporates one or more planar sets of six carbon atoms that are connected by delocalised electrons numbering the same as if they consisted of alternating single and double covalent bonds. ... In chemistry, the term van der Waals force originally referred to all forms of intermolecular forces; however, in modern usage it tends to refer to intermolecular forces that deal with forces due to the polarization of molecules. ... Look up cleavage in Wiktionary, the free dictionary. ... In chemistry, delocalized electrons are electrons in a molecule that do not belong to a single atom or a covalent bond. ... Electricity (from New Latin Ä“lectricus, amberlike) is a general term for a variety of phenomena resulting from the presence and flow of electric charge. ... Covalent redirects here. ... Not to be confused with electrical conductance, a measure of an objects or circuits ability to conduct an electric current between two points, which is dependent on the electrical conductivity and the geometric dimensions of the conducting object. ... For alternative meanings see metal (disambiguation). ... Image File history File links Download high resolution version (1762x1895, 1517 KB) Summary This illustration depicts eight of the allotropes (different molecular configurations) that pure carbon can take: a) Diamond b) Graphite c) Lonsdaleite d) Buckminsterfullerene (C60) e) C540 f) C70 g) Amorphous carbon h) single-walled carbon nanotube Created... Image File history File links Download high resolution version (1762x1895, 1517 KB) Summary This illustration depicts eight of the allotropes (different molecular configurations) that pure carbon can take: a) Diamond b) Graphite c) Lonsdaleite d) Buckminsterfullerene (C60) e) C540 f) C70 g) Amorphous carbon h) single-walled carbon nanotube Created... This article is about the mineral. ... For other uses, see Graphite (disambiguation). ... Lonsdaleite is a hexagonal allotrope of the carbon allotrope diamond, believed to form when meteoric graphite falls to Earth. ... The Icosahedral Fullerene C540 C60 and C-60 redirect here. ... Amorphous carbon is the name used for carbon that does not have any crystalline structure. ... // 3D model of three types of single-walled carbon nanotubes. ... This article is about the mineral. ... For the academic journal, see Tetrahedron (journal). ... The cubic crystal system is a crystal system where the unit cell is in the shape of a cube. ... Not to be confused with Silicone. ... General Name, Symbol, Number germanium, Ge, 32 Chemical series metalloids Group, Period, Block 14, 4, p Appearance grayish white Standard atomic weight 72. ... A chemical bond is the physical process responsible for the attractive interactions between atoms and molecules, and that which confers stability to diatomic and polyatomic chemical compounds. ... Mohs scale of mineral hardness characterizes the scratch resistance of various minerals through the ability of a harder material to scratch a softer. ... A 2002 Penguin Books paperback edition Diamonds Are Forever, published in 1956, is the fourth James Bond novel written by Ian Fleming. ... For other uses, see Graphite (disambiguation). ... Lonsdaleite is a hexagonal allotrope of the carbon allotrope diamond, believed to form when meteoric graphite falls to Earth. ... A regular hexagon A hexagon (also known as sexagon) is a polygon with six edges and six vertices. ... For other uses, see Crystal (disambiguation). ... The Icosahedral Fullerene C540 C60 and C-60 redirect here. ... In crystallography, the hexagonal crystal system is one of the 7 lattice point groups. ... Buckminsterfullerene (C60) Fullerenes are molecules composed entirely of carbon, taking the form of a hollow sphere, ellipsoid, or tube. ... // 3D model of three types of single-walled carbon nanotubes. ... Computer models of several stable NanoBud structures In nanotechnology, carbon NanoBuds are a newly discovered material combining two previously discovered allotropes of carbon: carbon nanotubes and fullerenes. ... Nanomaterials is the study of how materials behave when their dimensions are reduced to the nanoscale. ... Richard Buckminster â€œBuckyâ€ Fuller (July 12, 1895 â€“ July 1, 1983)[1] was an American visionary, designer, architect, poet, author, and inventor. ... Spaceship Earth in Epcot Center at Walt Disney World is perhaps one of the most famous examples of a large scale geodesic sphere. ... In mathematics, a spheroid is a quadric surface in three dimensions obtained by rotating an ellipse about one of its principal axes. ... Buckminsterfullerene (C60) Fullerenes are molecules composed entirely of carbon, taking the form of a hollow sphere, ellipsoid, or tube. ... A right circular cylinder An elliptic cylinder In mathematics, a cylinder is a quadric surface, with the following equation in Cartesian coordinates: This equation is for an elliptic cylinder, a generalization of the ordinary, circular cylinder (a = b). ... Aggregated diamond nanorods, or ADNRs, are an allotrope of carbon believed to be the hardest and least compressible known material, as measured by its isothermal bulk modulus; aggregated diamond nanorods have a modulus of 491 gigapascals (GPa), while a conventional diamond has a modulus of 442 GPa. ... 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. ... Ferromagnetism is a phenomenon by which a material can exhibit a spontaneous magnetization, and is one of the strongest forms of magnetism. ... Glassy carbon is a class of non-graphitizing carbon which is widely used as an electrode material in electrochemistry, as well as for high temperature crucibles and as a component of some prosthetic devices. ... Porosity is a measure of the void spaces in a material, and is measured as a fraction, between 0â€“1, or as a percentage between 0â€“100%. The term porosity is used in multiple fields including manufacturing, earth sciences and construction. ... Four sp3 orbitals. ... A polymer (from Greek: Ï€Î¿Î»Ï…, polu, many; and Î¼ÎÏÎ¿Ï‚, meros, part) is a substance composed of molecules with large molecular mass composed of repeating structural units, or monomers, connected by covalent chemical bonds. ... Nanotechnology refers to a field of applied science and technology whose theme is the control of matter on the atomic and molecular scale, generally 100 nanometers or smaller, and the fabrication of devices that lie within that size range. ...

Occurrence

Graphite ore

Raw diamond crystal.

Carbon is the fourth most abundant chemical element in the universe by mass after hydrogen, helium, and oxygen. Carbon is abundant in the Sun, stars, comets, and in the atmospheres of most planets. Some meteorites contain microscopic diamonds that were formed when the solar system was still a protoplanetary disk. Microscopic diamonds may also be formed by the intense pressure and high temperature at the sites of meteorite impacts.^[28] Graphite ore. ... Graphite ore. ... Wikipedia does not have an article with this exact name. ... Wikipedia does not have an article with this exact name. ... The abundance of a chemical element measures how relatively common the element is, or how much of the element there is by comparison to all other elements. ... Sol redirects here. ... This article is about the astronomical object. ... Comet Hale-Bopp Comet West For other uses, see Comet (disambiguation). ... Atmosphere is the general name for a layer of gases that may surround a material body of sufficient mass. ... This article is about the astronomical term. ... Willamette Meteorite A meteorite is a natural object originating in outer space that survives an impact with the Earths surface without being destroyed. ... This article is about the Solar System. ... A protoplanetary disc (also protoplanetary disk, proplyd) is an accretion disc surrounding a T Tauri star. ...

"Present day" (1990s) sea surface dissolved inorganic carbon concentration (from the GLODAP climatology)

In combination with oxygen in carbon dioxide, carbon is found in the Earth's atmosphere (in quantities of approximately 810 gigatonnes) and dissolved in all water bodies (approximately 36000 gigatonnes). Around 1900 gigatonnes are present in the biosphere. Hydrocarbons (such as coal, petroleum, and natural gas) contain carbon as well — coal "reserves" (not "resources") amount to around 900 gigatonnes, and oil reserves around 150 gigatonnes. With smaller amounts of calcium, magnesium, and iron, carbon is a major component of very large masses carbonate rock (limestone, dolomite, marble etc.). The total inorganic carbon (CT, or TIC)is the sum of inorganic carbon species in a solution. ... The Global Ocean Data Analysis Project (GLODAP) is a synthesis project bringing together oceanographic data collected during the 1990s by research cruises on the World Ocean Circulation Experiment (WOCE), Joint Global Ocean Flux Study (JGOFS) and Ocean-Atmosphere Exchange Study (OACES) programmes. ... Climatology is the study of climate, scientifically defined as weather conditions averaged over a period of time,[1] and is a branch of the atmospheric sciences. ... This article is about the chemical element and its most stable form, or dioxygen. ... Carbon dioxide (chemical formula: ) is a chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom. ... A gigaton (or gigatonne) is a metric unit of mass, equal to 1,000,000,000 (1 billion) metric tons, 1,000,000,000,000 (1 trill

Encyclopedia > Carbon

Contents

Characteristics

Allotropes

Occurrence