In Chapter, we found that the escape speed at the surface of a planet of radius R is ve = 2gR, where g is the acceleration due to gravity.

(a) At what temperature is vrms for O2 equal to the escape speed for the earth?

(b) At what temperature is vrms for H2 equal to the escape speed for the earth?

(c) Temperatures in the upper atmosphere reach 1000 K. How does this account for the low abundance of hydrogen in the earth's atmosphere?

(d) Compute the temperatures for which the rms speeds of O2 and H2 are equal to the escape velocity at the surface of the moon, where g is about one-sixth of its value on earth and R = 1738 km. How does this account for the absence of an atmosphere on the moon?