A. The temperature near the top of Saturn's cloud layer is about 110K. The temperature at the top of the earth's troposphere, at an altitude of about 20 km, is about 220K. Calculate the rms speed of hydrogen (H2) molecules in both of these environments. Give your answers in m/s and as a fraction of the escape speed from the respective planet.

B. Hydrogen gas is a rare element in the earth's atmosphere. In the atmosphere of Saturn, by constast, 96% of all molecules are H2. Explain why.

C. Suppose an astronomer claims to have discovered an oxygen (O2) on the Moon. How likely is this to be true? THe moon has a surface temp of about 220K near its equator.