Question

A boy sharpens a pencil at both the ends and then uses its black ends to complete an electrical circuit. Will the current flow through the electrical circuit? Give reason for your answer. Name the black substance of the pencil.

Answer 1

Part 1:

1. A boy sharpens a pencil at both ends and then uses its black ends to complete an electrical circuit.
2. A pencil Lead is made up of Graphite.
3. Graphite is formed by the layers of Carbon atoms where three Carbon atoms are joined by a strong covalent bond with the other three atoms forming a network of six Carbon rings and each Carbon has one free electron which makes it capable to flow current in a circuit and make it behave as a good conductor of electricity.
4. Therefore, the current will flow through the electrical circuit.

Part 2:

1. The black substance in the pencil is Lead, which is made up of Graphite, an allotrope of Carbon.