Alannah added a strip of zinc to a beaker containing a solution of copper sulfate, as shown in the photo. She expected to observe the immediate
formation of solid copper in the beaker but saw no evidence of a reaction.
Alannah predicted that the reaction was happening too slowly to observe.
Which statement could best explain this result?

Uranium has two naturally occurring isotopes. 238u has a natural abundance of 99.3% and 235u has an abundance of 0.7%. it is the rarer 235u that is needed for nuclear reactors. the isotopes are separated by forming uranium hexafluoride uf6, which is a gas, then allowing it to diffuse through a series of porous membranes. 235uf6 has a slightly larger rms speed than 238uf6 and diffuses slightly faster. many repetitions of this procedure gradually separate the two isotopes. what is the ratio of the rms speed of 235uf6 to that of 238uf6? express your answer to five significant figures.