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Homework Help: Balmer series

  1. Aug 12, 2006 #1
    in the balmer series the the higher energy level lines from the spectra are not observable using a spectroscope.

    is this because:
    they are outside the visible spectrum
    the intensity of the lines at high energy levels are much lower than the lower energy lines?

    If any of my reasons are wrong please correct me and if i have missed out something please tell me.
  2. jcsd
  3. Aug 12, 2006 #2
    The little chart that I have shows that for terms greater than n = 6
    (to n = 2, the Balmer series), the emitted radiation would fall in the ultraviolet spectrum. At n = 7 the wavelength emitted is 3970 Angstroms
    and becomes progressivlely shorter for the higher terms. Hope this
    answers your question.
  4. Aug 12, 2006 #3
    I am not sure but I think that the probablity of electron being in certain energy state depends on the temperature following the boltzman distribution. So if the electrons aren't in a higher energy state then they can't relax and emit the radiation.
  5. Aug 12, 2006 #4


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    Science Advisor

    Correct. The intensity which is a measure of the number of photons is related to the number of atoms which achieve a particular energy state. The highert the temperature, the more likely an atom will achieve a higher energy level through collisions. The 'color' of stars is related to temperature of the photosphere.

    Balmer Series (Second) (visible light) n=2 limit = 365 nm

    n=3, λ = 656 nm α, color emitted: red
    n=4, λ = 486 nm β, color emitted: bluegreen
    n=5, λ = 434 nm γ, color emitted: violet
    n=6, λ = 410 nm δ, color emitted: violet

    The remaining are UV, which would not be visible.

    Lyman lines are UV and Paschen are infrared.
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