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What evidence is there for electrons being particles?

  1. Feb 8, 2016 #1
    We know electrons can act as waves because of Young's Double split experiment, but what evidence is there to suggest they are particles?
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  3. Feb 8, 2016 #2


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    Ever watch TV on a old style cathode ray tube TV?
  4. Feb 8, 2016 #3
    Yes, how does that show particle behaviour, im not familiar with how it works.
  5. Feb 8, 2016 #4


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    The electrons (particles) hit the phosphorous coating on the inside of the front glass and it then emits photons.
  6. Feb 8, 2016 #5
    Okay thank you, that makes sense
  7. Feb 8, 2016 #6


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    I would say that your question has really been put a strange way round. We have been aware for ages of the particle nature of electrons (cathode rays). It's only fairly recently that their wave nature has been easy to demonstrate. The wavelength of an electron, travelling even at modest speed, is considerably less than that of light ( which is what Young used) and a true Young's Slits experiment is quite hard work to put together. It's fairly easy to demonstrate electron diffraction through a thin lattice of carbon atoms with School equipment, though.
    In fact, it's rather strange that you would quote the Young's Slits experiment with electrons yet not to be aware of how a beam of such electrons can be generated. Where did you read about the experiment?
  8. Feb 8, 2016 #7
    Yes I am aware of how odd the question may sound. But since I first started learning about electrons I had always been told it was a particle and I had just accepted it. Now that I am learning about wave-particle duality I am being told how we found out about an electrons wave-like properties through experiments. This made me think about how we knew electrons were particles in the first place.
  9. Feb 8, 2016 #8


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    Look up J. J. Thomson's experiments in the 1890s on "cathode rays", which we now know as streams of electrons. Even today, many undergraduate physics students perform a version of his experiment to measure the charge/mass ratio of electrons.
  10. Feb 8, 2016 #9


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    You want to be very careful about that. There actually IS no "wave particle duality" even though you'll still read about it even in actual physics books, to say nothing of pop-science.

    The point is that an electron is NOT a "particle" in the way you probably think it is. The word particle, when accurately used to describe some of an electrons characteristics, is not a classical particle, it is a quantum particle which is a different beast.

    An electron is properly categorized not as a particle or a wave but as a quantum object.
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