GCSE 2.6 Giant Covalent Molecules

Diamond and Graphite are both made of carbon atoms. Billions of atoms are joined together to form very large molecules held together by covalent bonds. To melt them, you have to break covalent bonds which are very strong. This is in contrast to simple covalent molecules like H2O and CO2. To melt them, no covalent bonds are broken, only weak intermolecular forces.