Question

rank these nonpolar molecules in order of increasing boiling point. (remember that the more electrons an atom or molecule contains, the more polarizable it is. polarizability and boiling point are directly related.)

Explanation:

Step1: Determine electron - count

Helium (He) has 2 electrons, methane ($CH_4$) has 6 (C) + 4×1 (H)=10 electrons, argon (Ar) has 18 electrons.

Step2: Relate to polarizability and boiling - point

Since polarizability increases with the number of electrons and boiling - point is directly related to polarizability, the order of increasing number of electrons (and thus increasing polarizability and boiling - point) is He < $CH_4$ < Ar.

Answer:

He < $CH_4$ < Ar