Why are van der waals forces important? a) they determine how strong dipole moments will be in polar covalent molecules b) they are the strongest type of intermolecular force that can act on polar and non-polar molecules c) they are primary intermolecular attractive forces that can act between non-polar molecules d) they are the strongest type of intermolecular force that can act between atoms

C) They are primary intermolecular attractive forces that can act between non-polar molecules

Explanation:

van der Waals forces are weak intermolecular attraction that exists between nonpolar molecules. The unsymmetrical distribution of the electron clouds causes negative charge to accumulate at one end of the molecule thus inducing a positive pole in the nearby molecule, and creating an attraction between the instantaneous dipoles.

the answer for sodium is 0.186

the answer for rubidium is 0.251