There is two different types but i’ll just do both meanings just incase.
Graham's Law of Diffusion: the rate of diffusion of one gas through another is inversely proportional to the square root of the density of the gas.
Graham's Law of Effusion: the rate of effusion of a gas is inversely proportional to the square root of the density of the gas.
hopes this helps..!
Cl2=3.17g/L
Ne=.901g/L
CO2=1.96g/l
therefore Cl2 is the densest gas under the given conditions.
Paraphrasing and summarizing
I don't know sorry I really need point