Carbon (from Latin: carbo "coal") is a chemical element with symbol C and atomic number 6. As a member of group 14 on the periodic table, it isnonmetallic and tetraval entmaking four electrons available to form covalent chemical bonds. There are three naturally occurring isotopes, with 12 Cand 13 C being stable, while 14 C is radioactive, decaying with a half-life of about 5,730 years. Carbon is one of the few elements known since antiquity.Latinchemical elementatomic numbergroup 14periodic tablenonmetallictetraval entelectronscovalentisotopes 12 C 13 C 14 Cradioactivehalf-lifefew elements known since antiquity
The different forms or allotropes of carbon include the hardest naturally occurring substance,diamond, and also one of the softest known substances, graphite.allotropesdiamondgraphite
Synthetic nanocrystalline diamond is the hardest material known.nanocrystalline diamond Diamond is the ultimate abrasive.abrasive Diamond is an excellent electrical insulator and has the highest breakdown electric field of any known material.insulator Diamond is the best known naturally occurring thermal conductorthermal conductor Diamond is highly transparent. Diamond crystallizes in the cubic system.cubic system Amorphous carbon is completely isotropic.isotropic
Graphite is one of the softest materials known. Graphite is a very good lubricant, displaying superlubricity.lubricantsuperlubricity Graphite is a conductor of electricity.conductor Some forms of graphite are used for thermal insulation but some other forms are good thermal conductors.thermal insulationother forms Graphite is opaque.opaque Graphite crystallizes in the hexagonal system.hexagonal system
Graphite is used in the pencil industry, but in a mixture with the clay to reduce its softness. Also, it is used as a lubricant in extremely high or low temperatures. His incredibly high melting point allows to make him crucibles for casting metals.