Uranium has two naturally occurring isotopes. U238 (atomic mass 238.0508 u) has
ID: 2228962 • Letter: U
Question
Uranium has two naturally occurring isotopes. U238 (atomic mass 238.0508 u) has a natural abundance of 99.275% and U235 (atomic mass 235.0439 u) has an abundance of 0.720%. The rarer isotope is needed for nuclear reactors. the isotopes are separated by forming uranium hexaflouride UF_6 which is a gas, then allowing it to diffuse through a series of porous membranes. Since the speeds of these two isotopes are only slightly different, many repetitions of the diffusion pathways can be used to separate these isotopes. Given the atomic mass of fluoride is 18.9984 u, determine how many times faster the UF_6 235 is than UF_6 238.Explanation / Answer
Centrifugal separation depends on the square of the mass so the ratio is 238^2 / 235^2 or 1.0257