The 235u isotope undergoes fission when bombarded with neutrons. however, its natural abundance is only 0.72 percent. to separate it from the more abundant 238u isotope, uranium is first converted to uf6, which is easily vaporized above room temperature. the mixture of the 235uf6 and 238uf6 gases is then subjected to many stages of effusion. calculate the separation factor, that is, the enrichment of 235u relative to 238u after one stage of effusion.