Allotropy:
The existence of two or more different forms of same element in the same state is called allotropy. There are three solid allotropic forms of carbon.
1. Diamond
2. Graphite
3. Bucky Balls
1. Diamond : Diamond is one of the crystalline forms of carbon. It is found chiefly in south Africa, Brazil, Australia and India: In pure state diamond is transparent and bright. It is the hardest nature substance known. Its density is about 3.51 g /cm³. It is a bad conductor of electricity. It has very high melting point about 3500°C. Colours in diamond are due to the presence of some metal oxides as impurities.
2. Graphite: Graphite is dark gray color crystalline solid with dull metallic luster. It is soft = greasy to feel. It is less dense than diamond and has density about 2.2g /cm'. It is good conductor of electricity and is used in the preparation of electrodes. It leaves black mark or paper, so it is used in the manufacture of lead pencils (Graphite + clay). It has high melting point about 3000°C.
3. Bucky Balls: Until 1980 pure solid carbon was thought to exist as diamond and graphite. In 1985 a startling discovery was made by two English researchers by the vaporized graphite. The mass spectrum peaks corresponded to clusters of carbon atoms as molecules 60 carbon atoms (Cro) and discovered that it is a different form of carbon, namely Cee molecules that were nearly spherical in shape. They proposed that carbon atoms of Coo form a ball, exactly lake soccer ball and has a highly symmetric structure. Cowas named buck minster fullerene or Bucky balls in short.
