At room temperature and atmospheric pressure, the halogens exist in different physical states. Chlorine is a gas, bromine is a liquid, and iodine is a solid. What are the boiling points and melting points for these elements? Estimate the volume of the Cl2, Br2, and I2 molecules. Comment on the effect of molecular volume on intermolecular forces. Compare and contrast the intermolecular interactions of the molecules. I think I can look for the boiling and melting points online. For the second question, do I use PV=nRT, where P=1 atm, n=1/molar mass of the gases, and T=298K? (not sure about n) For the 3rd and 4th question, can someone give me a hint? And does boiling and melting points relate to them in any way? Thank you.