Coal is formed from the remains of plants that lived millions of years ago. As the plants died, they were buried under layers of sediment and subjected to heat and pressure. Over time, this organic matter transformed into coal.

A pencil is made of graphite, which is a form of carbon. Graphite is also found in diamond, which is a crystallized form of carbon. Both graphite and diamond come from trees because they are formed from the carbon that is released when wood burns.