[RyanN]

Originally Posted by Mr. Freeman

I don't think the size of molecules changes when changing states from liquid to gas.

Is liquid not thicker than air? Try to move your arm through water, then do it through air. You will notice a big difference. Gas is much more free and energetic than liquid. That's my point. The actual size of the molecules don't change from changing states, but the different molecules in the gas form and in the liquid form are much different.