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Are protons and neutrons considered point particles?

  1. Jan 31, 2014 #1
    I find it confusing, I tried to google the topic but I still don't get it. What is the size and shape of subatomic particles? do they have a size or shape at all? and does the fact that protons and neutrons have larger mass than electrons mean they're bigger in size?
  2. jcsd
  3. Jan 31, 2014 #2


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    Protons and neutrons are made out of quarks and gluons, see Wikipedia:proton for a more detailed description. Shape and size are a bit problematic to define in quantum mechanics, but independent of the chosen definition, they have a non-zero size, and the shape is spherical within the measurement uncertainties.

    This has nothing to do with their mass. There are elementary particles* that have ~100 times the mass of proton and neutron.

    *or at least particles where no substructure is known, and with very good arguments for them to be really elementary
  4. Jan 31, 2014 #3

    Meir Achuz

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    The proton and neutron each have a radius of a little over 0.8 fm.
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