Graphite is a soft solid lubricant extremely difficult to melt. The reason for this anomalous behaviour is that graphite

Question

Graphite is a soft solid lubricant extremely difficult to melt. The reason for this anomalous behaviour is that graphite (A) is a non-crystalline substance (B) is an allotropic form of diamond (C) has molecules of variable molecular masses like polymers (D) has carbon atoms arranged in large plates of rings of strongly bonded carbon atoms with weak interplate bonds.

Tardigrade Admin · Accepted Answer

Graphite has a two-dimensional sheet like structure and each carbon atom is sp2 hybridised. The layer structure of graphite is much less compact than diamond. Since, the bonding between the layers involving only van der Waals’ forces is weak, these layers can slide over each other. This gives softness, greasiness and lubricating character to graphite.

Q. Graphite is a soft solid lubricant extremely difficult to melt. The reason for this anomalous behaviour is that graphite

is a non-crystalline substance

is an allotropic form of diamond

has molecules of variable molecular masses like polymers

has carbon atoms arranged in large plates of rings of strongly bonded carbon atoms with weak interplate bonds.