At room temperature, F2 and Cl2 are gases, Br2 is a liquid, and I2 is solid. The table below contains melting point data for these four substances. Use intermolecular forces of attraction to explain the trend in melting point values.
Melting point _____ going down the elements of Group 17 because the atoms increase in size and polarizability. As polarizability increases, intermolecular forces among the molecules, in the form of London dispersion forces, become _____. It, therefore, requires ______ energy, in the form of ______ temperatures, to break these intermolecular forces and transition the larger halogens from the solid to the liquid phase.