**1. The text uses the relation v_{rms} > v_{esc}/6 for the velocity needed to lose a component of the atmosphere, and from that obtains equation 19.6. Using the relation given in the lecture (v_{rms} > v_{esc}/10), how would equation 19.6 be modified? Give the new equation. **

**2. The Moon cannot hold on to water vapor (H _{2}O) or oxygen molecules (O_{2}) because it is too small. Referring to the example calculation for the Moon done in the lecture, how much more massive would the Moon have to be to retain O_{2}? How much more massive would it have to be to retain H_{2}O? Express your answer in units of the Moon's mass.**