Chapter - 2.4.1

Structure of Graphite & Diamond

• Diamond and graphite are allotropes of carbon which have giant covalent structures

• Allotropes are elements which have difference structures but are the same element with same physical forms of the element

• For example if we take carbon in solid state it could be in many forms like diamond and graphite

• All of giant covalent structures have billions of non-metal atoms as metals cant form covalent bond as they need electrons of there own to stable

  
  

Diamond

• In diamond, each carbon atom bonds with four other carbons, forming a tetrahedron

• All the covalent bonds are identical, very strong and there are no intermolecular forces

Diagram showing the structure and bonding arrangement in diamond

Properties Of Diamond

• Diamond has the following physical properties:

  • It does not conduct electricity

  • It has a very high melting point

  • It is extremely hard and dense

• All the outer shell electrons in carbon are held in the four covalent bonds around each carbon atom, so there are no freely moving charged particles to carry the current thus it cannot conduct electricity

• The four covalent bonds are very strong and extend in a giant lattice, so a very large amount of heat energy is needed to break the lattice thus it has a very high melting point

• Diamond ́s hardness makes it very useful for purposes where extremely tough material is required

• Diamond is used in jewelry due to its sparkly appearance and as cutting tools as it is such a hard material