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Homework Help: How does the spectral lines of Hydrogen occur?

  1. Oct 17, 2009 #1
    I'm not sure but I found this...

    [When an electron makes a transition from one energy level to another, the electron emits a photon with a particular energy. These photons are then observed as emission lines using a spectroscope. The Lyman series involves transitions to the lowest or ground state energy level. Transitions to the second energy level are called the Balmer series. These transitions involve frequencies in the visible part of the spectrum. In this frequency range each transition is characterized by a different color.]

    Any ideas of how it occurs? :)
    thanks =]
  2. jcsd
  3. Oct 17, 2009 #2


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    Homework Helper

    What specifically do you want explained? Why each transition emits a specific spectral line, why energy-level transitions occur, or why or something else? For the first question, it's because energy levels are quantized. When an electron jumps down from an excited state to a less excited state, it emits a photon with an energy equal to the difference in energy of the two states. Since a photon's energy depends linearly on its frequency, this emitted photon has a very specific frequency.

    As for why photons jump down to less-excited states in the first place, that's a process called simulated emission and is explained by quantum field theory, specifically quantum electrodynamics. Basically, excited electrons are in an unstable equilibrium and vacuum fluctuations--fluctuations in the electric field--disturb this equilibrium and cause them to fall to a lower energy level.
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