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Thread: colour

  1. #1 colour 
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    hey just wondering, what actually gives different ions/chemicals their colour. Im still my last year of high school so if its complicated some dumbing down would be appreciated.


    just wondering
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  3. #2  
    Geo
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    What makes elements different?


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  4. #3  
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    as far a i know, number of protons,electrons, and nuetrons
    just wondering
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  5. #4  
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    But i don't get how that would affect color.
    just wondering
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  6. #5  
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    It can get very complicated and difficult to explain if you venturei n too deep, but all in all here is the 'color' in a nutshell.

    The electrons you described orbit the core in a number of 'layers'. An electron can be hit by a lightwave and jump up to a higher layer if the frequency of that light is just right. (E = h*v. Energy of the wave is dependant on it's wavelenght).
    When a lightwave with the right energy hits the electron, and it does jump up to a higher layer it's called an excited electron.

    White light as we call it is actually a bundle of all wavelenghts (in the visual spectrum at least).
    Say you have a marble and you shoot light at it (the sun does that all the time for us). All the wavelenghts for all the colors would be reflected due to not meeting the right energy level required for excitation.
    One specific wavelenght however will have the right energy, and thus be absorbed and not reflected.

    This results in one of the many colours not reflecting off your marble. So if white light hits a marble and it absorbs the blue color, we will see it as red. (it can't show as blue, since that wavelenght is filtered out).
    This is allso why we see 'complementary colors'. So a marble we percieve as blue actually reflects all colours, exept for blue.
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  7. #6  
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    Keeping things as simple as possible...the theory is one in which an incoming photon (unit of light) collides with an atom and excites it...raising an electron to a higher energy level (whose energy change is equal to the energy of the absorbed photon). That said, an atom or molecule can only absorb a photon with a specific frequency (one that matches its allowed energy levels). Therefore,radiating the electromagnetic spectrum on an atom will produce what are known as "absorption bands", caused by the atom’s absorption of particular photons with a particular frequency (or energy). Because all atoms or molecules have different energy levels, they will each absorb photons with different frequencies, and therefore show different absorption bands.

    However, what our receptors detect is the emission spectra. This happens when an electron is in an excited state (has a high energy level) but eventually loses energy by descending one or more energy levels. As it descends it emits a photon characteristic of the particular energy level. And again, because each atom or molecule has its own characteristic energy levels, the photon emitted will also have an energy specific to the atom or molecule. As such, an atom or molecule will emit a number of different photons related to the energy of their specific energy levels. All of these emitted photons, together, give us the total “colour” of an atom or molecule.

    Finally, receptors in the human retina have the capacity to absorb photons with wavelengths ranging from 400 to 700 nm--this range of the electromagnetic spectrum is called “visible light” and makes up only a tiny part of the total electromagnetic spectrum, all of which we humans are unable to detect. An emitted photon (derived from a atom or molecule) hits the receptor and activates it...and the information is eventually relayed to the brain... where it is duly processed (in the visual cortex).
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  8. #7  
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    thanks guys, i think i get it now at least at a basic level
    just wondering
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