Due to its atomic structure as well as chemical and physical properties, carbon is a very unique non metallic element in nature. It has an atomic number of 6; atomic weight of 12.01 and a melting point of 360ºC. As part of its basic atomic composition, carbon has four outer electrons (meaning it has a valency of 4) which can be shared with other elements to form covalent chemical bonds. It is this capability of forming thousands of chemical bonds with other elements (including separate carbon atoms) that distinguishes carbon as a significant and versatile element.
In spite of complexities in formulae and calculations, the chemistry of carbon and its numerous compounds comprises the study of organic and chemical composition of all living beings including humans. Physical life on earth and carbon are interrelated owing to carbon’s fascinating chemical bonding capabilities. The process of photosynthesis in which carbon dioxide is absorbed and oxygen is released, by plants, is very vital for sustaining life on earth. The carbon-nitrogen cycle is also a significant phenomenon.
Carbon in various forms is present almost everywhere, from the atmosphere (as carbon dioxide) to the human body (being the second largest element, by weight; after oxygen, in our bodies). Also several other forms of carbon exist in nature such as hydrocarbons in fossil fuels, as the soft and cheap graphite to the hardest and one of the costliest of all substances, diamond and so on. Both graphite and diamond are composed of the same carbon element; but because of the difference in atomic structure they display diametrically opposite characteristics. It is interesting to note here that, graphite is the only non metallic substance which conducts electricity. This is because, out of the four electrons, one is freely available to move within the graphite, allowing the flow of electricity.
Carbon bonding with hydrogen in nature has led to the formation of hydrocarbons which is the heart and soul of the oil and gas as well as petrochemical industry. Even the steel industry is based on carbon because steel is the result of a chemical bondage between iron and carbon.
Carbon is also the basic structural element in all living organisms. When carbon bonds with hydrogen and oxygen, several biological compounds are generated. Some of these products are alcohols, fats and sugars and so on.
Incidentally there are also some inorganic compounds of carbon such as the carbon monoxide (poisonous), carbon dioxide and limestone (CaCO3) i.e. calcium carbonate.
As carbon dioxide is a greenhouse gas, carbon cycle across the world has now become an important issue with respect to global warming. The problems related to carbon dioxide emissions from the burning of fossil fuels have serious impact on the environment.Such carbon related issues have now come to be discussed in international forums.