Unlike diamond, graphite is a good conductor of electricity-explain.

Explanation

Each carbon atom in the crystal of diamond is `sp^3` -hybridised, i.e., all the electrons in the valance shell of carbon atom participate in forming sigma bonds with four neighbouring carbon atoms. Thus, there is no free electron left in the structure and so diamond is unable to conduct electricity. On the other hand, each carbon atom of graphite being `sp^2` -hybri9ised uses three of its valence electrons to form three `sigma` -bonds with three neighbouring carbon atoms. The fourth electron in `2p_z` -orbital (which stands perpendicular to the carbon layer) forms n -bond by overlapping sideways with the `2p_z` -orbital of any of the three adjacent carbon atoms. Electrons of the `pi`-bonds are delocalised through resonance in the entire crystal. Due to presence of such mobile electrons, graphite behaves as a good conductor of electricity.