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Dose E=hn means quantization of energy?

  1. Feb 11, 2012 #1
    I have an example class yesterday, but one question troubled me.

    In part (b), why does E=nhf?
    For me, it seems E=nh is enough, why does the equation involve frequency f after quantization?
     

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  2. jcsd
  3. Feb 11, 2012 #2
    One answer might be: The unit of E (energy) is a Joule, the unit of h (Plank's constant) is Joule time a second. If you want the equation to be correct you need to multiply h with something that has units of 1 over a second.


    Roman.
     
  4. Feb 11, 2012 #3
    What do you mean "E = nh is enough"? That equation is not correct, because as pointed out above, the units are not correct.
     
  5. Feb 11, 2012 #4
    h = energy per cycle.
    f = number of cycles per unit of time.
    your quantization must include a quantization of time.
     
  6. Feb 11, 2012 #5
    Thanks! I have forgotten to consider the unit.
     
  7. Feb 12, 2012 #6
    Energy within a single system is quantized, but there are different energies that result from following the E=nh model in different systems, so if you consider every possible system energy is continuous, just like the light spectrum.
     
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