Answer
See answer.
Work Step by Step
Use equation 13–9. The rms speed of a gas molecule is inversely proportional to the square root of its mass, assuming constant temperature.
Assume that the two gases are at the same temperature.
Use uranium hexafluoride molecules for the mass calculations.
Let “235” denote the uranium hexafluoride molecule containing U-235, and “238” denote the uranium hexafluoride molecule containing U-238.
$$\frac{v_{235}}{v_{238}}=\sqrt{\frac{m_{238}}{m_{235}}}=\sqrt{\frac{238.05+6(19.00)}{235.04+6(19.00)}}=\frac{1.0043}{1}$$
The uranium hexafluoride molecule containing U-235, the lighter isotope, travels slightly faster.
