Electronics & Semiconductors

Carbon nanotube transistors make the leap from lab to factory floor

Carbon nanotube transistors are a step closer to commercial reality, now that MIT researchers have demonstrated that the devices can be made swiftly in commercial facilities, with the same equipment used to manufacture the ...

Energy & Green Tech

UK electricity plant nears full switch away from coal

As the coronavirus pandemic undermines the production of cleaner renewable fuels, the UK's biggest electricity plant is close to using only biomass following a bumpy transition away from coal.

Energy & Green Tech

If all cars were electric, UK carbon emissions would drop by 12%

The COVID-19 lockdown has led to reduced pollution and emissions in the UK and around the world, providing a clear indication of how cars affect air quality and carbon emissions. But such a change is only temporary—millions ...

Business

Air France to cut 40% of domestic flights after bailout

Air France-KLM will slash 40 percent of its French domestic flights by next year in exchange for receiving seven billion euros ($7.7 billion) in emergency coronavirus funding backed by the French state, the company's chief ...

Engineering

Engineers develop near-zero emissions engine technology

Southwest Research Institute engineers have developed the next generation of clean diesel engine technology to reduce hazardous nitrogen oxides (NOx) and carbon dioxide emissions while minimizing fuel consumption. Working ...

Electronics & Semiconductors

Surrey unveils fast-charging super-capacitor technology

Experts from the University of Surrey believe their dream of clean energy storage is a step closer after they unveiled their ground-breaking super-capacitor technology that is able to store and deliver electricity at high ...

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Carbon

Carbon (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.

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