Why is graphite a conductor but not diamond?

Graphite conducts electricity because it has free electrons, while diamond does not conduct because all its electrons are tightly bonded.

Structure of Graphite

• Each carbon atom in graphite is bonded to three other carbon atoms.
• This leaves one free electron per atom that can move between layers.
• These free electrons act as charge carriers, allowing graphite to conduct electricity.
• Graphite has a layered hexagonal structure; layers are held together by weak forces, allowing easy movement of electrons.

Structure of Diamond

• Each carbon atom is bonded to four other carbon atoms by strong covalent bonds.
• All electrons are used in bonding; no free electrons are available.
• This rigid structure makes diamond an electrical insulator.