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
Global warming likely to be amplified by slow changes to Earth systems
Space & Earth / Earth Sciences
8 hours ago |
2.7 / 5 (18) |
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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 gases.
Climate talks end with eye on next year
Dec 19, 2009 |
1.8 / 5 (5) |
2
(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 |
4.1 / 5 (16) |
13
(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 |
2.5 / 5 (4) |
2
(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 |
3.4 / 5 (7) |
0
(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 |
1 / 5 (1) |
0
(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?
Review: Netbooks meet luxury in ultra-light Sony
Electronics / Consumer & Gadgets
Dec 16, 2009 |
3 / 5 (3) |
0
(AP) -- Netbooks have been a hit among laptop buyers because they're cheap and they're easy to carry. Now there's the option to pay a lot more and get a lot less - a lot less weight, that is.
NASA Calculates a Carbon Budget for California
Dec 16, 2009 |
2.8 / 5 (9) |
6
(PhysOrg.com) -- While world organizations struggle to find a benchmark and tracking standards for greenhouse gas (GHG) emissions, NASA has been supporting California’s new carbon emissions inventory report, using its satellite ...
New way to break some of the strongest chemical bonds
Dec 16, 2009 |
4.6 / 5 (23) |
0
(PhysOrg.com) -- Scientists at Cornell University in the U.S. have found a new way of breaking two of the strongest chemical bonds, at ambient temperature and pressure, and this breakthrough could lead to ...
NASA Outlines Recent Breakthroughs in Greenhouse Gas Research (w/ Video)
Space & Earth / Earth Sciences
Dec 15, 2009 |
3.7 / 5 (6) |
1
(PhysOrg.com) -- Researchers studying carbon dioxide, a leading greenhouse gas and a key driver of global climate change, now have a new tool at their disposal: daily global measurements of carbon dioxide ...
New results from a terra-ific decade in orbit
Space & Earth / Earth Sciences
Dec 15, 2009 |
5 / 5 (1) |
0
December 18, 2009, marks the tenth year since the launch of Terra, one of NASA's "flagship" Earth observing satellites. But the decade is more than just a mechanical milestone. With each additional day and ...
Home heating efficiencies offer 'hat trick' of savings: study
Dec 15, 2009 |
3 / 5 (1) |
0
Improving the energy efficiency of Maryland homes heated by natural gas would generate a "hat trick" of economic and environmental benefits over the next 10 years, including more than 80,000 new jobs, savings of hundreds ...
Going underground for a climate solution
Space & Earth / Earth Sciences
Dec 14, 2009 |
2 / 5 (4) |
3
(PhysOrg.com) -- Hoping to help fix the Earth's atmosphere, Catherine Peters recently found herself 4,100 feet underground.
New Study Turns Up the Heat on Soot's Role in Himalayan Warming (w/ Video)
Space & Earth / Earth Sciences
Dec 14, 2009 |
5 / 5 (2) |
0
(PhysOrg.com) -- Soot from fire in an unventilated fireplace wafts into a home and settles on the surfaces of floors and furniture. But with a quick fix to the chimney flue and some dusting, it bears no impact ...
The mammoths' swan song revised
Other Sciences / Archaeology & Fossils
Dec 14, 2009 |
4.4 / 5 (12) |
3
This is shown by samples of ancient DNA, analysed by an international team of research scientists under the leadership of Professor Eske Willerslev from Copenhagen University. Analyses of ancient DNA thereby ...
