Final answer:
Graphite is a lubricant because it has a layered structure with weak forces between the layers. These weak forces allow the layers to slide over each other easily, reducing friction. This makes graphite an effective lubricant in various applications.
Step-by-step explanation:
Graphite is a lubricant because of its layered structure and the weak forces of attraction between these layers. The layers in graphite are held together by strong covalent bonds within each layer, but there are weak van der Waals forces between the layers. These weak forces allow the layers to slide over each other easily, reducing the friction between surfaces.
When used as a lubricant, the layers of graphite can easily separate and form a thin film between two surfaces in contact. This film acts as a lubricating layer, preventing direct contact between the surfaces and reducing friction. The slippery nature of the graphite layers allows for smooth movement and less wear and tear.
For example, when a pencil is used, the friction between the paper and the graphite lead is reduced due to the lubricating effect of the graphite layers, making it easier for the pencil to slide across the paper.
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