Carbon 14 is not used for dating
The most common oxidation state of carbon in inorganic compounds is 4, while 2 is found in carbon monoxide and 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.Learn about different types of radiometric dating, such as carbon dating.Understand how decay and half life work to enable radiometric dating.It is the second most abundant element in the human body by mass (about 18.5%) after oxygen.The physical properties of carbon vary widely with the allotropic form.Carbon compounds form the basis of all known life on Earth, and the carbon-nitrogen cycle provides some of the energy produced by the Sun and other stars.
In general, covalent radius decreases with lower coordination number and higher bond order.
The system of carbon allotropes spans a range of extremes: Atomic carbon is a very short-lived species and, therefore, carbon is stabilized in various multi-atomic structures with different molecular configurations called allotropes.
The three relatively well-known allotropes of carbon are amorphous carbon, graphite, and diamond.
Its first four ionisation energies, 1086.5, 2352.6, 4620..7 k J/mol, are much higher than those of the heavier group 14 elements.
The electronegativity of carbon is 2.5, significantly higher than the heavier group 14 elements (1.8–1.9), but close to most of the nearby nonmetals as well as some of the second- and third-row transition metals.