Question

Graphite is used in pencils. It leaves a black trace of writing on paper because it consists of layers of carbon atoms that :

• A. are wound inside, like a long thread
• B. are attracted by paper material
• C. fall easily
• D. slide over each other

Answer 1

The correct option is D slide over each other

Graphite has layered structure layers are held by van der Waal forces. Graphite cleans easily between the layers and therefore, it is very soft and slippery. For this reason, it is used in pencil and as lubricants in machines running at high temperature.