(a) Write two points of difference in the structures of diamond and graphite.
(a) Write two points of difference in the structures of diamond and graphite.

(b) Explain why graphite can be used as a lubricant but diamond cannot.

Solution:

(a) (i) Carbon atoms in diamonds are bonded to four other carbon atoms.

The carbon atom in graphite is connected to just three other carbon atoms.

(ii) In a diamond, the crystal is arranged in a tetrahedral pattern.

The hexagonal ring structure of graphite crystals.

(b) Because of its softness, graphite may be utilised as a lubricant.

  1. Graphite is a material having a hexagonal crystal structure made up of layered sheets of carbon atoms.
  2. Graphite is a soft material with low specific gravity, low reactivity, and high electrical and thermal conductivity.
  3. Graphite is very soft, breaking down into thin, flexible flakes that readily glide over one another, leaving a greasy residue.
  4. As a result, graphite is an excellent “dry” lubricant that may be utilised in places where wet lubricants (such as lubricating oil) cannot.