Silicon dioxide (SiO2\text{SiO}_2SiO2) has a giant covalent structure similar to diamond. Carbon dioxide (CO2\text{CO}_2CO2) is a simple molecular gas at room temperature.
Explain why silicon dioxide has a very high melting point. Use ideas about bonding and energy in your answer.
Why is silicon dioxide described as having a giant lattice structure?
State the number of shared bonding pairs of electrons and the number of non-bonding (lone) pairs of outer-shell electrons in a water molecule (H2O\text{H}_2\text{O}H2O).
Carbon dioxide has a very low sublimation point of -78.5∘C78.5^\circ\text{C}78.5∘C. Explain why carbon dioxide has a low sublimation/boiling point. Use ideas about structure and forces in your answer.