Substances like sulfur, phosphorus, water, oxygen, nitrogen, carbon dioxide, iodine, chlorine, all the hydrocarbons, ect, exist as simple molecules in all 3 states of matter. Inside the molecule, the atoms are held together by strong covalent bonds and all the electrons are held strongly between atoms (ie, they are NOT declocalised). Between neighbouring molecules there are much weaker forces of attraction, called intermolecule forces.
On the basis of this information, predict the properties of covalent molecular substances in terms of MP, BP, state at RT, conductivity and hardness. Justify your predictions using examples above.