Related topics: climate change , carbon nanotube
Carbon
hideCarbon (pronounced /ˈkɑrbən/) is the chemical element with symbol C and atomic number 6. As a member of group 14 on the periodic table, it is nonmetallic and tetravalent—making four electrons available to form covalent chemical bonds. There are three naturally occurring isotopes, with 12C and 13C being stable, while 14C is radioactive, decaying with a half-life of about 5730 years. Carbon is one of the few elements known since antiquity. The name "carbon" comes from Latin language carbo, coal, and, in some Romance and Slavic languages, the word carbon can refer both to the element and to coal.
There are several allotropes of carbon of which the best known are graphite, diamond, and amorphous carbon. 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 (hence its name, from the Greek word "to write"). Diamond has a very low electrical conductivity, while graphite is a very good conductor. Under normal conditions, diamond has the highest thermal conductivity of all known materials. All the allotropic forms are solids under normal conditions but graphite is the most thermodynamically stable.
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.
Carbon is one of the least abundant elements in the Earth's crust, but 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 carbon is the second most abundant element by mass (about 18.5%) after oxygen. 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.
For more information about Carbon, read the full article at
Wikipedia.
This text uses material from Wikipedia and is available under the GNU Free Documentation License.
News tagged with carbon
Glacier melt adds ancient edibles to marine buffet
Space & Earth / Earth Sciences
Dec 23, 2009 |
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Glaciers along the Gulf of Alaska are enriching stream and near shore marine ecosystems from a surprising source - ancient carbon contained in glacial runoff, researchers from four universities and the U.S. ...
Scientists map speed of climate change
Dec 23, 2009 |
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New study finds that the average ecosystem will need to shift about a quarter mile per year to keep pace with global climate change.
UN climate official warns of Indian energy 'crisis'
Dec 23, 2009 |
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India's reliance on coal means the country is heading for an energy crisis unless it diversifies its sources of power, the chairman of the UN's top climate change panel predicted on Wednesday.
Taiwan unveils Asia's biggest solar plant: govt
Dec 23, 2009 |
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Taiwan has unveiled what it calls Asia's biggest solar power plant as the island, which imports almost all its energy, seeks to tap into clean renewable resources, the government said Wednesday.
Nanoparticles go platinum: NCEM instruments provide key images
Dec 21, 2009 |
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At Berkeley Lab's National Center for Electron Microscopy it was revealed that single-stranded DNA can disperse bundles of single-walled carbon nanotubes into individual tubes and serve as guideposts for synthesizing ...
Cornellians build computer climate-change model
Space & Earth / Earth Sciences
Dec 21, 2009 |
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(PhysOrg.com) -- Researchers are contributing to a new model of climate change that may give more accurate predictions of the amount of carbon dioxide and other greenhouse gases in Earth's future.
Molecular freight: Synthetic nanoscale transport system modeled on nature
Dec 21, 2009 |
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(PhysOrg.com) -- Just like our roads, there is a lot of traffic within the cells in our bodies, because cell components, messenger molecules, and enzymes must also be brought to the right places in the cell. One of these ...
Polluting pets: the devastating impact of man's best friend
Dec 21, 2009 |
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Man's best friend could be one of the environment's worst enemies, according to a new study which says the carbon pawprint of a pet dog is more than double that of a gas-guzzling sports utility vehicle.
Potatoes, algae replace oil in US company's plastics
Dec 21, 2009 |
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Frederic Scheer is biding his time, convinced that by 2013 the price of oil will be so high that his bio-plastics, made from vegetables and plants, will be highly marketable.
Global warming likely to be amplified by slow changes to Earth systems
Space & Earth / Earth Sciences
Dec 20, 2009 |
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Researchers studying a period of high carbon dioxide levels and warm climate several million years ago have concluded that slow changes such as melting ice sheets amplified the initial warming caused by greenhouse ...
Climate talks end with eye on next year
Dec 19, 2009 |
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(AP) -- A historic U.N. climate conference ended Saturday with only a nonbinding "Copenhagen Accord" to show for two weeks of debate and frustration. It was a deal short on concrete steps against global warming, ...
Acid oceans: the 'evil twin' of climate change
Dec 18, 2009 |
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(AP) -- Far from Copenhagen's turbulent climate talks, the sea lions, harbor seals and sea otters reposing along the shoreline and kelp forests of this protected marine area stand to gain from any global ...
Replicating Climate Change to Forecast its Effects
Dec 17, 2009 |
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(PhysOrg.com) -- Agricultural Research Service (ARS) scientists are replicating the effects of climate change to see what the future holds for soybeans, wheat and the soils where they grow.
Soil Microorganisms? Role Cited as a Missing Factor in Climate Change Equation
Dec 17, 2009 |
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(PhysOrg.com) -- Those seeking to understand and predict climate change can now use an additional tool to calculate carbon dioxide exchanges on land, according to a scientific journal article co-authored by a University of ...
NASA, Google offer more precise emissions tracking
Dec 17, 2009 |
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(AP) -- The question is a potential deal-killer: If nations ever agree to slash greenhouse gas emissions, how will the world know if they live up to their pledges?
