Question

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

(a) is a noncrystalline 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 bound carbon atoms with weak interplate bonds.

Answer 1

Correct option(d) has carbon atoms arranged in large plates of rings of strongly bound carbon atoms with weak interplate bonds.

Explanation:

C-atoms oi graphite form covalently bonded plates (layers) These layers are held together by weak forces of attraction. i.e., one layer can slide over other to cause lubricacy. lt cannot be melted easily as a large number of atoms being bonded strongly in the layer to form big entity.