Use electronegativity chart to figure out the type of intermolecular interactions: weak dispersive forces, London, hydrogen bonding (HB) + dipole-dipole (dip-dip), dipole-dipole only between the following molecules:
(a) HBr … HBr _ _ _ _ _ _ _ _ _ _ _ _ _
(b) PCl3 … PCl3 _ _ _ _ _ _ _ _ _ _ _
(c) CH4 … CH4 _ _ _ _ _ _ _ _ _ _ _