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I In the absorption, and emission spectra, what happens to some

  1. Jan 14, 2016 #1
    My name is Nicholas Lee, and I am studying neuroscience, and I am trying to find a way to find better ways in neuroimaging, and microscopy to see the brain better, to find better cure for Parkinson's disease, and Alzheimer's, and epilepsy If you have a four inch cubic block of glass, and carbon, light passes through the glass no problem, but the carbon will absorb some red, yellow, green, and blue light, but if you look at the carbon absorption for light, not all blue, green, yellow, and red light get absorbed by carbon, like in the diagram below.
    https://mail.google.com/mail/u/0/?ui=2&ik=1a702d60a0&view=fimg&th=1523d25f444c13eb&attid=0.1&disp=emb&realattid=ii_1523cf2013009e68&attbid=ANGjdJ9-7DrtqoE0M7wJfgoTZr28G3NCL-ExLoGlav_0S7KQ8nxfYPl4nDpdZpmjyWUM0A-2kB4FRYZTzdENCBwb-nlEWcXpzl29zqLWWFlucEnAYc2Tw3ZzjmYdvf4&sz=w496-h406&ats=1452806967907&rm=1523d25f444c13eb&zw&atsh=1
    Some materials have larger band gaps than others, glass is one of those materials, which means its electrons require much more energy before they can skip from one energy band to another, and back again.
    glass cannot absorb high wavelengths of light, but the glass will absorb ultraviolet waves, which have a smaller wavelength.
    So if the two four inch cubic block of glass, and carbon, are placed in a dark room with no light hitting the blocks at all, and you just shined the colors of light at the carbon, that did not excite the electrons to a higher shell energy level, what would happen.
    Question 1. Does the light from the blue, green, yellow, and red pass through the carbon block, but I think you would just see the block of carbon just be black right, even though certain colors of light are passing through it, is this correct.
    All light colors pass through the glass no problem, so for the carbon things are different, the amorphous material the glass is made from is not necessarily what is making the glass transparent, its the energy of the electrons in the glass that cannot get exited for the light, so the light gets transmitted through the block of glass.
    So for the carbon, does its electrons either absorb more energy, or because it has 2 electrons in shell 1, and 4 electrons in shell two, silicone which is mostly what glass is made from has two electrons in shell 1,and 8 in shell 2, and 4 in shell 3.
    So it cannot be the amount of electrons I think just the energy of electrons, but can you explain why the energy levels are different for some electrons.
    Here are a list of some ways to effect electron:
    1. Cold temperature, can this effect the way electron absorb photons of light.
    2. Certain wavelengths of light
    3. Amorphous material.
    4. energy of electrons, some wavelengths of light to not get absorbed by some electrons.
    Do you know of any other ways the electron can not get excited.
    Thank you for your help, anything helps, even a few words.
     
  2. jcsd
  3. Jan 15, 2016 #2

    mfb

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    The image link goes to your private mail folder, we cannot see the image.

    "Carbon block" is very unspecific. Graphite will absorb most visible light, reflect a bit and does not let light through. Diamond (without impurities) will reflect some part and let some part pass through, absorbing nearly nothing. Not only the element counts, the chemical bonds matter as well. I'll assume you mean graphite now.

    "Glass" is a very large class of materials (and includes things like porcelain), but I guess you mean typical glass used for windows.
    No, in the same way it doesn't do that in the previous scenario. The block would appear quite dark as before.
    The electronic structure and the chemical makeup are not independent.
    How much do you know about quantum mechanics?
    I don't understand the logic behind that list. The four things are completely different concepts.
     
  4. Jan 15, 2016 #3


    Great, thank you for your answer, you said" Graphite will absorb MOST visible light not all" if you meant MOST then there are some wavelengths of light that transsmission through the graphite right.
    Maybe that diagram you saw was the absorption, and emission spectrum for carbon gas, so here in the diagram below is a diagram for the emission of iron, hopefully solid iron because it takes a lot of energy to turn iron to a gas.
    If you notice there is a large gap in the blue, and red emission chart for iron, (hopefully solid iron).
    So does this mean *some* of that wavelength of blue, and red light does get transmission through a four inch solid cubed piece of iron.
    So all this blue, and red colored light has to do is pass through four inches of solid iron, the blue, and red light does not need to pass through any more thicker iron material more than four inches.
    https://mail.google.com/mail/u/0/?ui=2&ik=1a702d60a0&view=fimg&th=15247719d336dd43&attid=0.1&disp=emb&realattid=ii_1524759e5a833243&attbid=ANGjdJ90278Qn6KyWWlDyZNLysEDyjbpSN3uCz92I71Z7mC5LJUO6r_vhYLTAff0Z_UuB6_GI4_8mPpUE7R8J1YHsburDMQrh1TQKLUopbNPMBF4PUMYCup_O1yi30k&sz=w1000-h392&ats=1452897580611&rm=15247719d336dd43&zw&atsh=1
    Thank you for your help.
     
  5. Jan 15, 2016 #4

    mfb

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    This thread is so extremely similar to your other one that keeping both open just leads to confusion. Let's continue in the other thread.
     
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