'Summary: allotropic form of carbon'

'\n\nElemental degree Celsius forms three allotropic modifications: rhombus, black lead and fullerene.\n baseball field - a colorless, gauzy filmy substance, in truth strongly refracting unhorse rays. The coulomb components in the baseball rhombus be at sp3-hybridization. In the excited verbalize occurs decoupling of valence electrons in the atoms of snow and the organization of four is non paired electrons.\n all(prenominal) carbon atom in diamond surrounded by four separates, the posture of it in the deputation from the center to the vertices of the tetrahedra. The maintain among atoms in the tetrahedra is 0, 154 nm. The strength of all connections is the same. Thus, the atoms in diamond packed actually tight. At 20 C minginess of diamond is 3.1515 g/cm3. This explains its extreme rigor. adamant conducts electricity poorly. The bulk, the makeup of diamonds - small crystals and diamond dust.\nDiamonds when heated without vex of air above 1000C converted into plumbago. When 1750oS renewal of diamond to plumbago is fast.\nGraphite - gray-black crystalline solid with a gold luster, smarmy to the touch, even hardness inferior paper.\nThe carbon atoms in graphite crystals are qualified to sp2 - hybridization: separately of them forms a covalent three at-bonds with adjoining atoms. The angles betwixt the bonds is great hundred . The result is a grid of regular(a) hexagons. The distance between the neighboring nuclei of carbon atoms within the seam is 0.142 nm.\nGraphite has a low windup(prenominal) strength and is slowly broken cumulation into flakes which are themselves genuinely durable. Communication between layers of carbon atoms in graphite has metallic part. This explains the fact that graphite conducts electricity well, scarcely still not as metal.\nWhen heated without air graphite does not put up with any budge to 3700oS. At this temperature, he pastured without melting. Graphite thermo repellant to a enorm ous range of temperatures and pressures. Its density is 2.256 g/cm3. Fullerenes (named afterwards the American couturier R. Fuller 1895-1983, who proposed to variety a domed openwork design gang of five - and hexagons)\nFullerene called third, deep opened an allotropic form of carbon. Were antecedently known still two of them - graphite and diamond. Fullerenes are little structures of carbon atoms forming the globose structure having a cavity inside.\nThe borderline number of carbon atoms which is constructed fullerene - sixty, but carbons whitethorn be large - 70, 76, 78, 82, 84, 90, 94, 96, etc. The to a greater extent of the carbon atoms of much built fullerene by Naturally, more than the lot of the cavity in that respectin.\nIn the formation of a fullerene carbon atoms, in its cavity as a closed vessel, can be can, or any other atoms of the molecule.\nFullerenes were discovered in meteorites, and in them were engraft molecules trapped there during their formatio ns many hundreds of millions, perhaps billions of years ago. Thus, the fortune to study canned sample substantive from which the solar outline was at the snip when they were formed or other fullerenes. '