In naturally occurring uranium atoms, 99.3% are 238U (atomic mass = 238 u, where u = 1.6605 × 10-27 kg) and only 0.7% are 235U (atomic mass = 235 u). Uranium-fueled reactors require an enhanced proportion of 235U. Since both isotopes of uranium have identical chemical properties, they can be separated only by methods that depend on their differing masses. One such method is gaseous diffusion, in which uranium hexafluoride (UF6) gas diffuses through a series of porous barriers. The lighter 235UF6 molecules have a slightly higher rms speed at a given temperature than the heavier 238UF6 molecules, and this allows the two isotopes to be separated. Find the ratio of the rms speeds of the two isotopes at 23.0 °C?