Question

Difference between diamond and graphite is due to -

• A. Graphite combines with oxygen to form carbon dioxide but diamond does not.
• B. The atoms in each have different masses
• C. The crystal structure in diamond is different from that in graphite
• D. All

Answer 1

The correct option is C The crystal structure in diamond is different from that in graphite

Diamond and graphite are two allotropic forms of carbon and their crystal structure is different from each other as shown in figure. In diamond $C$ atom is ${sp}^3$ hybridised due to tetrahedral structure. Graphite has planar hexagonal layers of carbon atoms held together by weak Vander Waals forces and $C$ is ${sp}^2$ hybridised. Electrons are delocalised over the whole sheet. Diamond is hard because of rigid 3D carbon network in space but graphite is soft and slippery because of delocalised and mobile $\pi$ electrons over the whole sheet.