Carbon

Three isotopes occur naturally, C and C being stable, while C is a radionuclide, decaying with a half-life of about 5,730 years.

Carbon ( 6 C) has 15 known isotopes, from 8 C to 22 C, of which 12 C and 13 C are stable.

Three isotopes occur naturally, C and C being stable, while C is a radionuclide, decaying with a half-life of about 5,730 years.

Carbon-14 ( 14 C), or radiocarbon, is a radioactive isotope of carbon with an atomic nucleus containing 6 protons and 8 neutrons.

The atoms of carbon can bond together in diverse ways, resulting in various allotropes of carbon.

Carbon is capable of forming many allotropes (structurally different forms of the same element) due to its valency.

Carbon's abundance, its unique diversity of organic compounds, and its unusual ability to form polymers at the temperatures commonly encountered on Earth enables this element to serve as a common element of all known life.

Carbon is a primary component of all known life on Earth, representing approximately 45–50% of all dry biomass.

The best known allotropes are graphite, diamond, and buckminsterfullerene.

Graphite, archaically referred to as plumbago, is a crystalline form of the element carbon with its atoms arranged in a hexagonal structure.

Carbon is one of the few elements known since antiquity.

It is nonmetallic and tetravalent—making four electrons available to form covalent chemical bonds.

The elements generally classified as nonmetals include one element in group 1 (hydrogen); one in group 14 (carbon); two in group 15 (nitrogen and phosphorus); three in group 16 (oxygen, sulfur and selenium); most of group 17 (fluorine, chlorine, bromine and iodine); and all of group 18 (with the possible exception of oganesson).

Under normal conditions, diamond, carbon nanotubes, and graphene have the highest thermal conductivities of all known materials.

Graphene (/ˈɡræfiːn/) is an allotrope of carbon in the form of a single layer of atoms in a two-dimensional hexagonal lattice in which one atom forms each vertex.

Carbon (from carbo "coal") is a chemical element with the symbol C and atomic number 6.

Carbon (from carbo "coal") is a chemical element with the symbol C and atomic number 6.

Among the more common of such native elements are copper, silver, gold, carbon (as coal, graphite, or diamonds), and sulfur.

Three isotopes occur naturally, C and C being stable, while C is a radionuclide, decaying with a half-life of about 5,730 years.

Carbon-13 ( 13 C) is a natural, stable isotope of carbon with a nucleus containing six protons and seven neutrons.

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 dioxide consists of a carbon atom covalently double bonded to two oxygen atoms.

The most common oxidation state of carbon in inorganic compounds is +4, while +2 is found in carbon monoxide and transition metal carbonyl complexes.

Carbon monoxide consists of one carbon atom and one oxygen atom, connected by a triple bond that consists of two covalent bonds as well as one dative covalent bond.

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.

Coal is mostly carbon with variable amounts of other elements; chiefly hydrogen, sulfur, oxygen, and nitrogen.

It is the second most abundant element in the human body by mass (about 18.5%) after oxygen.

The human body is composed of elements including hydrogen, oxygen, carbon, calcium and phosphorus.

Three isotopes occur naturally, C and C being stable, while C is a radionuclide, decaying with a half-life of about 5,730 years.

Carbon-12 ( 12 C) is the more abundant of the two stable isotopes of carbon (carbon-13 being the other), amounting to 98.93% of the element carbon; its abundance is due to the triple-alpha process by which it is created in stars.

The most common oxidation state of carbon in inorganic compounds is +4, while +2 is found in carbon monoxide and transition metal carbonyl complexes.

The lowest oxidation state is −4, as for carbon in methane or for chromium in [Cr(CO) 4 ] 4−.

Carbon compounds form the basis of all known life on Earth, and the carbon–nitrogen cycle provides some of the energy produced by the Sun and other stars.

The CNO cycle (for carbon–nitrogen–oxygen) is one of the two known sets of fusion reactions by which stars convert hydrogen to helium, the other being the proton–proton chain reaction (pp-chain reaction).

Although thermodynamically prone to oxidation, carbon resists oxidation more effectively than elements such as iron and copper, which are weaker reducing agents at room temperature.

There are simple redox processes, such as the oxidation of carbon to yield carbon dioxide (CO 2 ) or the reduction of carbon by hydrogen to yield methane (CH 4 ), and more complex processes such as the oxidation of glucose (C 6 H 12 O 6 ) in the human body.

Carbon compounds form the basis of all known life on Earth, and the carbon–nitrogen cycle provides some of the energy produced by the Sun and other stars.

Roughly three quarters of the Sun's mass consists of hydrogen (~73%); the rest is mostly helium (~25%), with much smaller quantities of heavier elements, including oxygen, carbon, neon, and iron.

This exothermic reaction is used in the iron and steel industry to smelt iron and to control the carbon content of steel:

Steel is an alloy of iron and carbon, and sometimes other elements.

At elevated temperatures, carbon reacts with oxygen to form carbon oxides and will rob oxygen from metal oxides to leave the elemental metal.

An oxocarbon or oxide of carbon is a chemical compound consisting only of carbon and oxygen.

Carbon's abundance, its unique diversity of organic compounds, and its unusual ability to form polymers at the temperatures commonly encountered on Earth enables this element to serve as a common element of all known life.

Most commonly, the continuously linked backbone of a polymer used for the preparation of plastics consists mainly of carbon atoms.

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.

Tungsten carbide (chemical formula: WC) is a chemical compound (specifically, a carbide) containing equal parts of tungsten and carbon atoms.

Once considered exotic, fullerenes are nowadays commonly synthesized and used in research; they include buckyballs, carbon nanotubes, carbon nanobuds and nanofibers.

A fullerene is an allotrope of carbon whose molecule consists of carbon atoms connected by single and double bonds so as to form a closed or partially closed mesh, with fused rings of five to seven atoms.