The 235u isotope (atomic mass = 235.00) undergoes fission when bombarded with neutrons. however, its natural abundance is only 0.72 percent. to separate it from the more abundant 238u isotope (atomic mass = 238.00), uranium is first converted to uf6, which is easily vaporized above room temperature. the mixture of 235uf6 and 238uf6 gases is then subjected to many stages of effusion. calculate how much more quickly 235uf6 effuses than 238uf6. give the answer as the ratio of rates of 235uf6 to 238uf6 to four decimal places.