关键词: 麦克斯韦速率分布率, 大气层, 逃逸速度

Abstract: With the Maxwell＇s speed distribution law, we analyze quantitatively some real problems. For ex- ample, we explain why there is no atmosphere on the moon and why there is a few concentrations of gases with small molecular mass on the earth＇s atmosphere, etc. , which should enhance the enthusiasm of students for learning physics.

Key words: Maxwell＇s speed distribution law, atmosphere, velocity of escape