(a) What is graphite? Of what substance is graphite made?
(b) Describe the structure of graphite with the help of a labelled diagram.
(c) Why is graphite a good conductor of electricity but diamond is a non-conductor of electricity?
(d) State any two uses of graphite.
(a) Graphite is a greyish-black opaque substance. It is made up of carbon.
(b) The structure of graphite is very different from that of diamond. A graphite crystal consists of layers of carbon atoms or sheets of carbon atoms. Each carbon atom in a graphite layer is joined to other three carbon atoms by strong covalent bonds to form flat hexagonal rings. The various layers of carbon atoms in graphite are held together by weak Van der Waals forces. Due to this sheet like structure, graphite is a comparatively soft substance.
(c) Due to the presence of free electrons in a graphite crystal, it conducts electricity however; a diamond crystal does not have free electrons so it does not conduct electricity.
(d) (i) Used as a lubricant
(ii) Used for making pencil leads.