why does iodine have a higher boiling point than chlorine?
If we look at group 7 of the periodic table, we can see that iodine is below chlorine. The trend in going down a group in the periodic table is that the number of electron shells increases, therefore, number of electrons increases. This means a molecule of iodine (I2) has more electrons than a molecule of chlorine (Cl2) so the van der waal's inter molecular forces are stronger and require more energy to overcome meaning the boiling point of iodine is higher than that of chlorine.
