Thermal energy, the Sun, and diffusion: Putting it all together In 1896...

Thermal energy, the Sun, and diffusion: Putting it all together

In 1896, Lord Rayleigh showed that a mixture of two gases of different atomic masses could be separated by allowing some of it to diffuse through a porous membrane into an evacuated space. Rayleigh proposed that the molecules of lighter gas diffuse through the membrane faster, leaving the heavier gas behind in the original space. He described this “separation factor” as equal to where m1 is the molecular weight of a lighter gas and m₂ is the molecular weight of a heavier gas. Give a reason why the separation factor depends on the square root of the ratio of the molecular masses.