Carbon is an element with 6 electrons, 6 protons and 6 neutrons. Carbon is the sixth most abundant element in the universe. All most all living organisms contain carbon. Human body consists of 18% carbon by weight. The plants store energy from the sun in the chemical bonds of the sugar molecule which is a carbon compound. In nature carbon can exist in the form of an element or a compound.
Carbon is also found in fossil fuels such as petroleum, natural gas and coal, Mineral substances such as carbonates, cyanides and carbon dioxide gas. Carbon exists in its natural state as graphite and diamonds.
Atomic number: 6
Atomic mass: 12.011 g.mol -1
Density: 2.2 g.cm-3 at 20°C
Electron Configuration: [He] 2s22p2
Classification: non-metal Melting Point: 3500.0 °C
Boiling Point: 4827.0 °C
Density: 2.267 g / cm-3 (graphite form), 3.513 g/cm-3 (diamond form)
Ionization energy: 1086.1 kJ.mol -1
One of the properties that make Carbon unique is its ability to create four covalent bonds. Because of this properties, carbon forms long chain-like structure of various lengths and configurations. These compounds formed so have unique and specialized chemical properties. This property of carbon is called Catenation.
Carbon compounds with same atoms (same molecular formula) can have different arrangement (different structural formula) this property of carbon is called isomerism.
Hydrogen plays a significant role in carbon chemistry. The special relationship between carbon and hydrogen is so important that it leads to study of a class of chemicals known as Hydrocarbons which consist of combination of only Hydrogen and Carbon atoms.
The pure carbon exist in four forms. The four allotrope of carbon are diamond, graphite, buckminsterfullerne (C60), and Ceraphite (white carbon). Allotropes of carbon have different phisical and chemical properties. Among all allotropes Ceraphite is the softest known materials while diamond is the hardest.
Typically carbon atom has six protons and six neutrons in its nucleus. But carbon also exists in other two isotopic forms. The isotopes of carbon are:
Carbon with six protons and six neutrons in its nucleus is called C-12. Carbon with six protons and seven neutrons in its nucleus is called C-13. Carbon with six protons and eight neutrons in its nucleus is called C-14.
C-14 is formed due to the bombarding of C-12 with cosmic rays.This form of carbon under go radioactive decay. The production and decay of C-12 and C-14 are balanced so that they remain always at the same ratio to each other in carbon dioxide. Plants use both C-12 and C-14 for photosynthesis in this same ratio. There by it is distributed to all the living in the food chain.
Since fossils, mummies, and wooden relics, can not exchange carbon with the air. The C-12 that was present at death remains, but the C-14 decays radioactively and becomes less in ratio to C-12. The changing ratio can be detected easily by counting the amount of C-14. The amount of change tells the age of the specimen this process is called Carbon Dating or radioactive dating. Radioactive carbon-13 is used as a tracer for many chemical reactions.
Carbon in its various forms has an innumerable use, a few of which include: