State the crystal structures of SiO2 and CO2 and why one has a higher melting point than the other.

SiO₂ forms a giant covalent structure while CO₂ has a simple molecular structure.In the giant covalent structure of SiO_2, strong covalent bonds hold the atoms together in the structure, while CO₂ has only weak intermolecular forces or dipole-dipole forces between molecules to hold the molecules together. The covalent bonds of SiO₂ are much stronger than weak intermolecular forces of CO₂ and so take more energy to be broken, therefore the melting point of SiO₂ is much higher than that of CO₂ .