Question

which substance has the strongest (London) dispersion forces? Cl2 , F2 , Br2 , I2

Answer 1

London D Forces are a function of the polarizability of the molecule, which in turn is determined by the number of electrons and the volume over which they are spread. As u move down the column, the number of electrons increases and hence, the volume increases. Therefore, the london dispersion forces will be greatest for those with a larger amount of electrons. Does that make sense?