Intermolecular forces????

Question

What intermoleclar forces hold I2(iodine) in solid state:

(a) hydrogen bonds

(b) Ionic bonds

(c) ion-dipole interactions

(d) dipole-dipole interactions

(e) London dispersion forces

Answer 1

(e)

Answer 2

London Dispersion forces, cannot be hydrogen, ionic, or ion-dipole because those are for molecules more than one element. Dipole dipole are for molecules ranging more than one element as well. London best qualifies since the I2 molecule is pretty massive and many random movements in electrons occur.

Answer 3

Iodine molecules, which is nonpolar, are held together in a solid by London dispersion forces.  

The answer is (e).

======== Follow up ==========

London dispersion forces do not depend on the mass of a molecule.  Instead LDF are proportional to the number of electrons and the volume which they occupy.  It is simply coincidental that more massive molecules have more electrons and are bigger.