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

Covalent Structures

Diamond

Properties:

• Very high melting point (many strong covalent bonds)
• Very hard (covalent bonds are hard to break)
• Does not conduct electricity (all of the outer/valence electrons are used to form bonds so there are no delocalised electrons to conduct electricity)

Uses:

1. Cutting tools (hard and abrasive)

Graphite

Properties:

• Very high melting point (many strong covalent bonds)
• Soft and slippery (forces of attraction between the layers are weak so they can slide over each other)
• Conducts electricity (only 3 of the 4 valence electrons are used up. This means that there is 1 delocalised electron per carbon atom to conduct electricity through the structure.)

Uses:

1. Lubricant
2. Electrodes for electrolysis