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Homework Help: Speed of Electrons and energy level

  1. Nov 25, 2006 #1
    Do electrons on higher energy levels have increased speed? This is confusing because if we look at it considering a centripetal force inversly proportional to the radius squared, the speed decreases. However since it's on a higher energy level, dosen't that mean the speed actually increases?
  2. jcsd
  3. Nov 25, 2006 #2
    Well you can think of it like this. v^2/r equals a constant, if r increases v must also increase to maintain the same centripetal acceleration. If youre up to rotational motion, then you know the formula v=omega*r. If angular velocity is the same, than as you go farther out, linear velocity must be greater to catch up to the other electrons.
    Bohr realized this and thought that if electrons were giving off light, they were losing energy and must be moving closer and closer to the nucleus with lower and lower velocity until they collided with it. He resolved this with the Bohr model and quantized energy levels
  4. Nov 26, 2006 #3
    Why should the centripetal force be constant? Isn't proportional to the inverse of the radius squared?
  5. Nov 27, 2006 #4
    It is not constant I should think. If you have covered electric fields you would know and yes you are right that it is inversely proportional to r. The v=r*omega analogy is correct though.
  6. Nov 27, 2006 #5


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