EXERCISE 18


Astronomers decide to conduct further observations and studies of this 
minor planet mentioned in Exercise 17 above.

(a) At the surface of this minor planet, the average temperature is 
    270 K and the atmospheric pressure is 0.1 Earth atmosphere.  Could 
    rivers or lakes of liquid Substance X exist on the surface of this 
    planet?  Explain your answer.

(b) A space probe lands on the surface of this minor planet and 
    collects 0.45 liter of atmosphere for further study.  How many 
    molecules of Substance X are collected?  Use the temperature and 
    pressure given in Part (a) above.