Why is SiO2 a solid whereas CO2 is a gas at room temeperature?
The main factor influencing a given compound's state is the strength of intermolecular forces - those need to be larger than the thermal energy for a compound to be solid/liquid. For CO2 the only type of interactions possible are the weak Van der Waals forces, whereas in the case of SiO2 the solid is stabilised by the presence of strong covalent linkage all throughout the crystal lattice.
WG
Related Chemistry A Level answers
All answers ▸Explain why hydrogen bromide has a higher boiling point than hydrogen chloride.
Back in 1950s, it was common to have as house cleaning items bleaching solution (containing sodium hypochlorite) and ammonia (used to remove, for example, hair dye stains). However, many people ended up in hospital after using them both, why?
What is meant by the term salt? And how would you confirm if the salt had chloride ions in?
How would you name complex organic compounds?