- Covalent bonds are bonds between nonmetals in which electrons are shared between the atoms
- Covalent compounds can be arranged in simple molecular or giant molecular lattices
- Simple molecular lattices: iodine, buckminsterfullerene (C60) and ice
- Giant molecular: silicon(IV) oxide, graphite and diamond
Graphite, diamond and buckminsterfullerene are all allotropes of carbon; they are different structural forms of the same element (which is carbon).