Carbon is the only element which has an entire branch of chemistry devoted solely to it and its reactions—organic chemistry—so named because most of the compounds that all life requires contain carbon. Natural carbon occurs in several different forms, including graphite, diamond and the rare buckminsterfullerene C Graphite carbon is used in steel making, printing, sugar refining, respirators, water purification and treatment and in pencil lead and batteries.
Diamond carbon is used in jewelry and in many cutting applications. Diamonds also have the distinction of having the highest melting point of any substance C.
Buckminsterfullerene is currently too rare to have any industrial use but it holds great potential for the future. The many carbon compounds make up one of the largest and most useful group of substances that exist. It can also bond with up to four other atoms because of its electron arrangement. Atoms are arranged as a nucleus surrounded by an electron cloud, with electrons zinging around at different distances from the nucleus.
Chemists conceive of these distances as shells, and define the properties of atoms by what is in each shell, according to the University of California, Davis. Carbon has two electron shells, with the first holding two electrons and the second holding four out of a possible eight spaces. When atoms bond, they share electrons in their outermost shell. Carbon has four empty spaces in its outer shell, enabling it to bond to four other atoms.
It can also bond stably to fewer atoms by forming double and triple bonds. In other words, carbon has options. And it uses them: Nearly 10 million carbon compounds have been discovered, and scientists estimate that carbon is the keystone for 95 percent of known compounds, according to the website Chemistry Explained.
Carbon's incredible ability to bond with many other elements is a major reason that it is crucial to almost all life. Carbon's discovery is lost to history. The element was known to prehistoric humans in the form of charcoal. Carbon as coal is still a major source of fuel worldwide, providing about 30 percent of energy worldwide, according to the World Coal Association. Coal is also a key component in steel production, while graphite, another form of carbon, is a common industrial lubricant.
Carbon is a radioactive isotope of carbon used by archaeologists to date objects and remains. Carbon is naturally occurring in the atmosphere. Plants take it up in respiration, in which they convert sugars made during photosynthesis back into energy that they use to grow and maintain other processes, according to Colorado State University. Animals incorporate carbon into their bodies by eating plants or other plant-eating animals. Carbon has a half-life of 5, years, meaning that after that time, half of the carbon in a sample decays away, according to the University of Arizona.
Because organisms stop taking in carbon after death, scientists can use carbon's half-life as a sort of clock to measure how long it has been since the organism died. This method works on once-living organisms, including objects made of wood or other plant material. Carbon is a long-studied element, but that doesn't mean there isn't more to discover. In fact, the same element that our prehistoric ancestors burned as charcoal may be the key to next-generation tech materials.
By vaporizing graphite with lasers, the scientists created a mysterious new molecule made of pure carbon, according to the American Chemical Society. The energy released in this reaction is made available for the cells. Natural abundance. Carbon is found in the sun and other stars, formed from the debris of a previous supernova. It is built up by nuclear fusion in bigger stars.
It is present in the atmospheres of many planets, usually as carbon dioxide. On Earth, the concentration of carbon dioxide in the atmosphere is currently ppm and rising. Graphite is found naturally in many locations. Diamond is found in the form of microscopic crystals in some meteorites. In combination, carbon is found in all living things. It is also found in fossilised remains in the form of hydrocarbons natural gas, crude oil, oil shales, coal etc and carbonates chalk, limestone, dolomite etc.
Help text not available for this section currently. Elements and Periodic Table History. Carbon occurs naturally as anthracite a type of coal , graphite, and diamond. More readily available historically was soot or charcoal.
Ultimately these various materials were recognised as forms of the same element. Not surprisingly, diamond posed the greatest difficulty of identification. Naturalist Giuseppe Averani and medic Cipriano Targioni of Florence were the first to discover that diamonds could be destroyed by heating. In they focussed sunlight on to a diamond using a large magnifying glass and the gem eventually disappeared. Pierre-Joseph Macquer and Godefroy de Villetaneuse repeated the experiment in Then, in , the English chemist Smithson Tennant finally proved that diamond was just a form of carbon by showing that as it burned it formed only CO 2.
Atomic data. Bond enthalpies. Glossary Common oxidation states The oxidation state of an atom is a measure of the degree of oxidation of an atom.
Oxidation states and isotopes. Glossary Data for this section been provided by the British Geological Survey. Relative supply risk An integrated supply risk index from 1 very low risk to 10 very high risk.
Recycling rate The percentage of a commodity which is recycled. Substitutability The availability of suitable substitutes for a given commodity. Reserve distribution The percentage of the world reserves located in the country with the largest reserves. Political stability of top producer A percentile rank for the political stability of the top producing country, derived from World Bank governance indicators.
Political stability of top reserve holder A percentile rank for the political stability of the country with the largest reserves, derived from World Bank governance indicators. Supply risk. Coal Diamond Graphite Coal. Relative supply risk 4. Relative supply risk 6. Relative supply risk 8. Young's modulus A measure of the stiffness of a substance. Shear modulus A measure of how difficult it is to deform a material.
Bulk modulus A measure of how difficult it is to compress a substance. Vapour pressure A measure of the propensity of a substance to evaporate. Pressure and temperature data — advanced.
Listen to Carbon Podcast Transcript :. You're listening to Chemistry in its element brought to you by Chemistry World , the magazine of the Royal Society of Chemistry. Hello, this week to the element that unites weddings, wars, conflicts and cremations and to explain how, here's Katherine Holt.
Any chemist could talk for days about carbon. It is after all an everyday, run-of-the-mill, found-in-pretty-much-everything, ubiquitous element for us carbon-based life forms. An entire branch of chemistry is devoted to its reactions. In its elemental form it throws up some surprises in the contrasting and fascinating forms of its allotropes.
It seems that every few years a new form of carbon comes into fashion - A few years ago carbon nanotubes were the new black or should I say 'the new bucky-ball' - but graphene is oh-so-now! But today I'm going to talk about the most glamorous form that carbon can take - diamond.
For millennia diamond has been associated with wealth and riches, as it can be cut to form gemstones of high clarity, brilliance and permanence. Diamonds truly are forever! Unfortunately, diamond also has a dark side - the greed that diamond induces leads to the trade of so-called 'conflict diamonds' that support and fund civil wars.
Mans desire for diamond has led alchemists and chemists over many centuries to attempt to synthesise the material. After many fraudulous early claims diamond was finally synthesised artificially in the s. Scientists took their inspiration from nature by noting the conditions under which diamond is formed naturally, deep under the earth's crust. This was an impressive feat, but the extreme conditions required made it prohibitively expensive as a commercial process.
Since then the process has been refined and the use of metal catalysts means that lower temperatures and pressures are required.
Crystals of a few micron diameter can be formed in a few minutes, but a 2-carat gem quality crystal may takes several weeks. These techniques mean its now possible to artificially synthesise gemstone quality diamonds which, without the help of specialist equipment, cannot be distinguished from natural diamond.
It goes without saying that this could cause headaches among the companies that trade in natural diamond! It is possible to turn any carbon based material into a diamond - including hair and even cremating remains! Yes - you can turn your dearly departed pet into a diamond to keep forever if you want to! Artificial diamonds are chemically and physical identical to the natural stones and come without the ethical baggage. However, psychologically their remains a barrier - if he really loves you he'd buy you real diamond - wouldn't he?
From the perspective of a chemist, materials scientist or engineer we soon run out of superlatives while describing the amazing physical, electronic and chemical properties of diamond. It is the hardest material known to man and more or less inert - able to withstand the strongest and most corrosive of acids. It has the highest thermal conductivity of any material, so is excellent at dissipating heat.
That is why diamonds are always cold to the touch. Having a wide band gap, it is the text book example of an insulating material and for the same reason has amazing transparency and optical properties over the widest range of wavelengths of any solid material. You can see then why diamond is exciting to scientists. Its hardness and inert nature suggest applications as protective coatings against abrasion, chemical corrosion and radiation damage.
Its high thermal conductivity and electrical insulation cry out for uses in high powered electronics. Its optical properties are ideal for windows and lenses and its biocompatibility could be exploited in coatings for implants.
These properties have been known for centuries - so why then is the use of diamond not more widespread? The reason is that natural diamond and diamonds formed by high pressure high temperature synthesis are of limited size - usually a few millimeters at most, and can only be cut and shaped along specific crystal faces. This prevents the use of diamond in most of the suggested applications. However, about 20 years ago scientists discovered a new way to synthesise diamond this time under low pressure, high temperature conditions, using chemical vapour deposition.
If one were to consider the thermodynamic stability of carbon, we would find that at room temperature and pressure the most stable form of carbon is actually graphite, not diamond. Strictly speaking, from a purely energetic or thermodynamic point of view, diamond should spontaneously turn into graphite under ambient conditions! Clearly this doesn't happen and that is because the energy required to break the strong bonds in diamond and rearrange them to form graphite requires a large input of energy and so the whole process is so slow that on the scale of millennia the reaction does not take place.
It is this metastability of diamond that is exploited in chemical vapour deposition. The carbon-based molecules then deposit on a surface to form a coating or thin film of diamond. Actually both graphite and diamond are initially formed, but under these highly reactive conditions, the graphitic deposits are etched off the surface, leaving only the diamond. The films are polycrystalline, consisting of crystallites in the micron size range so lack the clarity and brilliance of gemstone diamond.
While they may not be as pretty, these diamond films can be deposited on a range of surfaces of different size and shapes and so hugely increase the potential applications of diamond.
Challenges still remain to understand the complex chemistry of the intercrystalline boundaries and surface chemistry of the films and to learn how best to exploit them. This material will be keeping chemists, materials scientists, physicists and engineers busy for many years to come. However, at present we can all agree that there is more to diamond than just a pretty face! Katherine Holt extolling the virtues of the jewel in carbon's crown. Next week we're heading to the top of group one to hear the story of the metal that revolutionised the treatment of manic depression.
Its calming effect on the brain was first noted in , by an Australian doctor, John Cade, of the Victoria Department of Mental Hygiene. He had injected guinea pigs with a 0. Cade then gave his most mentally disturbed patient an injection of the same solution. The man responded so well that within days he was transferred to a normal hospital ward and was soon back at work.
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