Carbon dating used
The resulting network is 2-dimensional, and the resulting flat sheets are stacked and loosely bonded through weak van der Waals forces.This gives graphite its softness and its cleaving properties (the sheets slip easily past one another).
All carbon allotropes are solids under normal conditions, with graphite being the most thermodynamically stable form at standard temperature and pressure.Graphite is soft enough to form a streak on paper (hence its name, from the Greek verb "γράφειν" which means "to write"), while diamond is the hardest naturally occurring material known.Graphite is a good electrical conductor while diamond has a low electrical conductivity.They are chemically resistant and require 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 transition metal carbonyl complexes.The three relatively well-known allotropes of carbon are amorphous carbon, graphite, and diamond.
Once considered exotic, fullerenes are nowadays commonly synthesized and used in research; they include buckyballs, The amorphous form is an assortment of carbon atoms in a non-crystalline, irregular, glassy state, not held in a crystalline macrostructure.
Carbon is the sixth element, with a ground-state electron configuration of 1s, of which the four outer electrons are valence electrons.
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.
It is present as a powder, and is the main constituent of substances such as charcoal, lampblack (soot) and activated carbon.
At normal pressures, carbon takes the form of graphite, in which each atom is bonded trigonally to three others in a plane composed of fused hexagonal rings, just like those in aromatic hydrocarbons.
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.