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Homework Help: Exam revision help

  1. Jun 19, 2003 #1
    this was a question in a prevoius year exam that im really stuck on.

    An atom has an energy level 1.8 eV above ground state. When excited, it returns to the ground state and emits a photon. Ccalculate the energy and wavelength of the photon.

    help me please
    thank you
  2. jcsd
  3. Jun 19, 2003 #2


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    Doesn't seem very difficult...

    Energy of photon = energy lost by electron as it goes down the energy level.

    Also, E = hf = h*c/l

    Plug in the numbers...

    And don't forget that 1 eV = 1.6 * 10^-19 J
    Last edited: Jun 19, 2003
  4. Jun 19, 2003 #3
    but what numbers do i plug in. Do i have to use a fomula on the 1.8eV first to get the numbers or just use that.
  5. Jun 19, 2003 #4
    1 eV = 1.6x10^-19 Joules

    Convert it to Jays.
  6. Jun 19, 2003 #5
    thank you very much
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