(a) What is diamond? Of what substance is diamond made?(b) Describe the structure of diamond. Draw a simple diagram to show the arrangement of carbon atoms in diamond.
(c) Explain why, diamond has a high melting point.
(d) State any two uses of diamond.

(a) Diamond is a colourless transparent substance having extraordinary brilliance. It is made of carbon.

(b) A diamond crystal is a giant molecule of carbon atoms. Each carbon atom in the diamond crystal is linked to four other carbon atoms by strong covalent bonds. The four surrounding carbon atoms are at the four vertices of a regular tetrahedron. This rigid structure of diamond makes it a very hard substance.