ETYM French carbone, from Latin carbo coal; cf. Skr. çrâ to cook.
An abundant nonmetallic tetravalent element occurring in three allotropic forms: amorphous carbon and graphite and diamond; occurs in all organic compounds; SYN. C, atomic number 6.
Nonmetallic element, symbol C, atomic number 6, relative atomic mass 12.011. It occurs on its own as diamond, graphite, and as fullerenes (the allotropes), as compounds in carbonaceous rocks such as chalk and limestone, as carbon dioxide in the atmosphere, as hydrocarbons in petroleum, coal, and natural gas, and as a constituent of all organic substances.
In its amorphous form, it is familiar as coal, charcoal, and soot. The atoms of carbon can link with one another in rings or chains, giving rise to innumerable complex compounds. Of the inorganic carbon compounds, the chief ones are carbon dioxide, a colorless gas formed when carbon is burned in an adequate supply of air; and carbon monoxide (CO), formed when carbon is oxidized in a limited supply of air. Carbon disulfide (CS2) is a dense liquid with a sweetish odor. Another group of compounds is the carbon halides, including carbon tetrachloride (tetrachloromethane, CCl4). When added to steel, carbon forms a wide range of alloys with useful properties. In pure form, it is used as a moderator in nuclear reactors; as colloidal graphite it is a good lubricant and, when deposited on a surface in a vacuum, obviates photoelectric and secondary emission of electrons. Carbon is used as a fuel in the form of coal or coke. The radioactive isotope carbon-14 (half-life 5,730 years) is used as a tracer in biological rese.
Arch. Analysis of interstellar dust has led to the discovery of discrete carbon molecules, each containing 60 carbon atoms. The C60 molecules have been named buckminsterfullerenes because of their structural similarity to the geodesic domes designed by US architect and engineer Buckminster Fuller.
The element has the following characteristic reactions. with air or oxygen It burns on heating to form carbon dioxide in excess air, or carbon monoxide in a limited supply of air.
C + O2 ® CO2 DH = -394 kJ mol-1.
2C + O2 ® 2CO.
With metal oxides.
It reduces many metal oxides at high temperatures. Fe2O3 + 3C ® 2Fe + 3CO with steam It forms water gas (a cheap, useful, industrial fuel) when steam is passed over white-hot coke.
C + H2O ® CO + H2.
With concentrated acids.
With hot, concentrated sulfuric or nitric acids it forms carbon dioxide. + prikaži više

ETYM AS. col; akin to Dutch kool, Old High Germ. chol, cholo, German kohle, Icel. kol, pl., Swed. kol, Dan. kul; cf. Skr. jval to burn. Related to Kiln, Collier.
(Homonym: cole).
Carbonized vegetable matter deposited in the carboniferous period; the material is combustible and has been used for heating since the mid nineteenth century.
Black or blackish mineral substance formed from the compaction of ancient plant matter in tropical swamp conditions. It is used as a fuel and in the chemical industry. Coal is classified according to the proportion of carbon it contains. The main types are anthracite (shiny, with about 90% carbon), bituminous coal (shiny and dull patches, about 75% carbon), and lignite (woody, grading into peat, about 50% carbon). Coal burning is one of the main causes of acid rain.
In the second half of the 18th century, coal became the basis of the Industrial Revolution. Coal fields are widely distributed throughout the temperate N hemisphere, the greatest reserves being in Europe, W Siberia, and the US. In the Southern hemisphere, Australia is a major producer. An increasing use, from 1950–70, of cheap natural gas and oil as fuel and for the production of electricity halted when the energy crisis of the 1970s led to greater exploitation of coal resources. Coal is becoming a major source of synfuel (synthetic gasoline). In the Fischer–Tropsch process (used in Germany in World War II and today in South Africa), the coal is gasified and then catalysts are used to reconstitute it into diesel and jet fuel. In the degradation process (under development in the US for high-octane motor fuel), a liquid fuel is directly produced by adding hydrogen or removing carbon from the coal. + prikaži više

ETYM Latin, from Greek anthrax coal, carbuncle.
A highly infectious animal disease (especially cattle and sheep); it can be transmitted to people; SYN. splenic fever.
Severe infectious disease of cattle and sheep, communicable to human beings; boil cause by this.
Disease of livestock, occasionally transmitted to humans, usually via infected hides and fleeces. It may develop as black skin pustules or severe pneumonia. Treatment is with antibiotics. Vaccination is effective.
Anthrax is caused by a bacillus (Bacillus anthracis). In the 17th century, some 60,000 cattle died in a European pandemic known as the Black Bane, thought to have been anthrax. The disease is described by the Roman poet Virgil and may have been the cause of the biblical fifth plague of Egypt. + prikaži više