Carbon

• Carbon is found in nature as diamond and graphite.
• Fullerene and graphene are synthetic carbon.
• Carbon can also be found as compounds combining with other elements in petroleum, coal, natural gas, limestone, carbon dioxide and sugar (CHO), etc.
• All living things have carbon containing compounds such as carbohydrates, fats proteins and nucleic acids, etc.
• If an element, can exist more than one form, in the same physical state, it is said to exhibit allotropy or polymorphism.
• The different forms of an element in the same physical state that possess different physical properties are known as allotropes of that element.
• Allotropes of an element may have different chemical properties.
• Diamond, graphite, fullerene and graphene are allotropes of carbon.
• Oxygen and ozone are allotropes of oxygen.
• Rhombic sulphur and monoclinic sulphur are allotropes of sulphur.
• Diamond is transparent and shines in the presence of light.
• The layers in graphite are bonded through weak forces known as van der Waals forces, allowing graphite to act as a lubricant.
• Diamond is the hardest among all naturally occurring substances.
• Diamond has a giant structure, containing millions of carbon atoms in a three-dimensional network of strong carbon-carbon covalent bonds, making it very hard and having a very high melting point (3550 °C).
• The distance between the layers in graphite is more than the distance between adjacent carbon atoms, making the layers weakly bonded to each other and causing graphite to be soft.
• The melting point of graphite is 3700 °C.
• Due to the presence of free electrons, graphite is a good conductor of electricity and heat.
• In graphite, each carbon atom is surrounded by three other carbon atoms in the same plane, resulting in layers of hexagons.
• Due to its layered structure, graphite is soft and has a soapy touch.