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Charge in the electrons and protons

  1. Jul 30, 2003 #1
    dear reader,
    the electrons are negative and protons are positive was proved by jj thompson. he proved it using the discharge tube. the cathode rays which started from the cathode(-) to the anode(+) was said to be negative because of its attraction to the anode. is there any other experiment or theory that proves that electrons are negative and protons are positive?????????????????:smile:. i am only in 9th std, so please dont be angry with me for this question.
  2. jcsd
  3. Jul 30, 2003 #2
    If someone is angry because you ask a question in order to learn try to think of it as his/her problem not yours.:smile:

    I will split your question into 2 parts.

    1) You are correct that the experiment proves that electrons and protons have opposite charge. This is a fundamental fact and there should be more than one way to prove it. I'll defer to others with more time or knowledge.

    In another experiment, it was proven that the mass of the electron is very small compared to that of the proton (about 1/1875 the mass of a proton).

    2) What we call the charge of the electron (negative) and the charge of the proton (positive) is arbitrary and I believe due to Ben Franklin's choice. They could have been called left and right charges or up and down, really any pair of words with opposite meaning. His choice stuck.
  4. Jul 31, 2003 #3

    thanks mmwave. i fell that electrons can also be positive provided that the protons are positive. i get it clear now , they are just opposite charges.
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