Question

Give any two differences between the properties of diamond and graphite. What causes these differences?

Answer 1

Sl.No	Diamond	Graphite
1.	Diamond has a rigid structure that makes it a hard material.	Graphite has a layered structure that makes it a soft material.
2.	Diamond does not conduct electricity.	Graphite is a good conductor of electricity

The differences in their properties is due to the different arrangement of carbon atoms in both the allotropes. In diamond, one carbon atom is linked to four other carbon atoms by strong covalent bonds to form regular tetrahedron. While in graphite, one carbon atom is joined to three other carbon atoms by covalent bonds to form a flat hexagonal ring. In graphite, the various layer of carbon atoms are held together by a weak van der Waals force.
Graphite is a good conductor, as in its crystal, only three valence electrons of a carbon atom are used in the bond formation, while the fourth valence electron is free. The free movement of these electrons in the graphite crystal allows the conductivity of electric current.