Write scientific reasons: 

(a) Graphite is a conductor of electricity 

(b) Graphite is not used as a lubricant at high temperature

(a) Graphite conducts electricity because each carbon atom in graphite is bonded to three other carbon atoms, leaving one free electron per atom. These free electrons move easily, making graphite a good conductor.

(b) Graphite is not used as a lubricant at high temperatures because at very high heat it oxidizes and loses its slippery layers, making it ineffective as a lubricant.

Explanation

• Graphite as conductor: Its hexagonal layers have delocalized electrons that act as charge carriers. These electrons move freely across layers, allowing current to pass.
• Lubricant property: At room temperature, graphite works well because layers of carbon slide over each other. But at high temperatures in the presence of oxygen, graphite oxidizes into carbon dioxide, losing lubrication properties.

Thus, graphite is an excellent conductor but not suitable as a high-temperature lubricant.