1.45 explain how the uses of diamond and graphite depend on their structures, limited to graphite as a lubricant and diamond in cutting

Diamond
In diamond, each carbon atom is joined to four other carbon atoms, forming a giant covalent structure. As a result, diamond is very hard and has a high melting point. This explains why it is used in cutting tools

Graphite

In graphite, each carbon atom is joined to only three other carbon atoms, this results in carbon sheets that are 'stacked' on top of each other. These layers can slide over each other, this means that graphite is much softer than diamond. It is used in pencils, and as a lubricant

NOTE: Diamond does not conduct electricity but graphite does