The boiling points of halogens increase in the following order F2
a. ion-dipole
b. hydrogen-bonding
c. ion-ion
d. dispersion forces
e. permanent dipole-dipole
AND WHY?
in order for the molecule to change phase from liquid to gas and evaporates, it needs to overcome the force from other molecules around it. as the force bigger evaporation gets harder. so e has the highest force and higher boiling point.