Structures of Carbon
Diamond
Each carbon forms 4 covalent bonds in a giant lattice.
- Very hard, very high melting point → cutting tools.
- Does not conduct (no free electrons — all 4 outer electrons are bonded).
Graphite
Each carbon forms 3 bonds, making layers of hexagons with weak forces between layers.
- Layers slide → soft, slippery → lubricant, pencils.
- One delocalised electron per atom → conducts electricity.
Graphene
A single layer of graphite (one atom thick). Strong, light, conductive → electronics, composites.
Fullerenes & nanotubes
Carbon in balls or tubes (e.g. buckminsterfullerene C₆₀). Huge surface area and strength → drug delivery, catalysts, strong light materials.
Comparison
| Structure | Bonds per C | Conducts? | Property |
|---|---|---|---|
| Diamond | 4 | No | Hardest |
| Graphite | 3 | Yes | Slippery |
| Graphene | 3 | Yes | Strong + thin |
Exam tip
Same element, different structures → very different properties. Graphite conducts (delocalised electrons); diamond doesn't (all 4 electrons bonded).