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Thread: Absorption Spectrum

  1. #1 Absorption Spectrum 
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    I was just wondering if anyone knew anything about fluorescence in relation to absorption spectrums.
    This is my grasp of it:
    The spinach leaf fluoresced because a molecule’s electron reached an excited state, resulting from the absorption of a photon by a pigment, and when this electron returned to its ground state, the resultant accompanying loss of energy is given off as another photon, fluorescence. The graph of the relationship between absorbance and wavelength illustrate this in the drastic drop in absorbance. As the graph suggests, this only occurs once which is why we only saw the fluorescence appear once on the chromatography paper, and thus, demonstrates how the drop in absorbance is an indication of fluorescence.

    If this is wrong please tell me...it would be greatly appreciated! Thank you.


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  3. #2  
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    Florescence occurs when a material absorbs a photon, then dumps some of the energy into something else (usually a vibration). Since some of the energy was sent elsewhere, when it relaxes by emitting a photon it emits a photon with a lower energy than the one it absorbed.


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  4. #3 Re: Absorption Spectrum 
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    Quote Originally Posted by ender7x77
    I was just wondering if anyone knew anything about fluorescence in relation to absorption spectrums.
    This is my grasp of it:
    The spinach leaf fluoresced because a molecule’s electron reached an excited state, resulting from the absorption of a photon by a pigment, and when this electron returned to its ground state, the resultant accompanying loss of energy is given off as another photon, fluorescence. The graph of the relationship between absorbance and wavelength illustrate this in the drastic drop in absorbance. As the graph suggests, this only occurs once which is why we only saw the fluorescence appear once on the chromatography paper, and thus, demonstrates how the drop in absorbance is an indication of fluorescence.

    If this is wrong please tell me...it would be greatly appreciated! Thank you.
    Hm. Basically it'll absorb x wavelength and emit (fluoresce) on x's complementary wavelength.

    But say it absorbs a "red" wavelength. That means it should emit a "green" wavelength. (700 nm for red ish 500 for green ish).

    I don't think it's a drastic drop in absorbance though as the indication where it fluoresces. Perhaps there is but how can you pinpoint the exact wavelength? You can't. At least very well if there is a correlation. But if there is I haven't heard of it and I have started studying luminescence.

    At least we took absorbance spectra and the luminescence of a molecule. We didn't use the absorbance spectrum to determine where it fluoresced, just to where it *absorbed*. We used the fluorimeter to measure luminescence. The wavelength it luminesced (fluoresced or phosphoresced - it'll measure both) at and the emittance intensity.
    (Fe)male = male alloyed with iron for greater strength, ductility, and magnetism.
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