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Color of Microscopic Particles?

  1. May 28, 2014 #1
    Do molecules, atoms, and subatomic particles have color? If so, what? Is it even possible to determine if they do or not (Can electron microscopes see electrons?)? Is color even relevant at lengths this small? I would elaborate more but these questions are fairly straightforward.
  2. jcsd
  3. May 28, 2014 #2


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    For atoms and molecules color can be defined as the spectral lines of the given species.
  4. May 28, 2014 #3


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    Color is either (a) from light emitted by the object - a luminous body, or (b) from light reflected by the body.

    Atoms and molecules emit different wavelengths of light when excited differently; these are the spectral lines referred to by mathman. For example you can generate the spectrum for different atoms and their ions at this NIST site, and "see" what colors they would emit under varying conditions: http://physics.nist.gov/PhysRefData/ASD/lines_form.html

    An elementary discussion can be found here: http://en.wikipedia.org/wiki/Emission_spectrum
    In addition they show the spectral lines for hydrogen and iron.

    The absorption spectrum is also of interest: http://en.wikipedia.org/wiki/Absorption_spectrum

    For case (b), the reflected light, this depends upon the incident light, and which color are absorbed by the reflecting body - whatever is not absorbed, some will be scattered back to you and will provide the color. An apple observed under different lighting conditions will have different colors - which is why artists like to vary the lighting.

    Finally, to answer your question: no, electron microscopes don't see color, nor do they see electrons. I've done a lot of work with both, and the color you will see is due to the phosphor at the detector; green is quite popular!
  5. May 29, 2014 #4
    Each animal need radiation to see the objects. I think molecules, atoms, and subatomic particles will be seen to have different colors depending on the radiation or radiations used to see them. They don't have a permanent color. I can't say anything with certainty, I mean don't believe me completely.
    Last edited: May 29, 2014
  6. May 29, 2014 #5


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    It depends on what you mean by "have color".
    Molecules, atoms, and smaller can be made to emit, absorb, and/or scatter light of various wavelengths, and you could call that "having a color" if you wish... but this property bears no resemblance to our intuitive notion of color as something that you perceive when you look at a macroscopic object.
  7. May 29, 2014 #6


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    There a rather fundamental misunderstanding here that makes this question a bit vague.

    First of all, an electron microscope DOES NOT observe electrons. It USES electrons, instead of light as in the regular optical microscope, to view objects.

    Secondly, what you should ask that makes this a clearer physics question is whether atoms, molecules, particles, etc emit EM radiation, and if they emit such radiation with a unique characteristics. This makes it clearer because "color" in this context simply means an EM radiation of a particular frequency.

    As has been stated, atoms and molecules emit a SPECTRUM of EM frequency, most of these are of a unique set. This is why we could identify the elements and make up of celestial objects.

    On the other hand, elementary particles do not often have such uniqueness. I can take a bunch of electrons and shake them up and down at different frequencies and produce different frequencies of EM radiation. Electrons have been used in accelerators and synchrotron centers to produce EM radiation ranging from IR all the way to hard x-rays.

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