Is there a reason that a proton has a positive charge while an electron has a negative charge? Are these just names that were given to the charges or was there a reason for making a proton have a positive charge?

  • $\begingroup$ Positive and negative are just conventions. What is not a convention however is that electrons and protons have charges of opposite sign so that $q_{\text{electron}} q_{\text{proton}}<0$. $\endgroup$
    – Omar Nagib
    Commented Oct 6, 2015 at 13:25
  • $\begingroup$ As a word of warning: while everybody agrees that the charge of the electron is negative, there is no agreement over whether the electron has charge $e$ (with $e<0$) or charge $-e$ with $e>0$. $\endgroup$ Commented Oct 6, 2015 at 13:28
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    $\begingroup$ Possible duplicate of Who (and Why) started the "electrons are negative, protons are positive" convention? $\endgroup$ Commented Oct 6, 2015 at 13:55

2 Answers 2


There is no particular reason why one should be of such a sign and the other of the other. The choice is mostly historical and the opposite choice (positive charge for the electron and negative for the proton) would work as well with just some slight sign changes in the equations. The only important part is that their charge be opposites.


Protons are not an elementary particle, whilst electrons are. Protons are made up of Quarks, electrons aren't made up of difference constituent parts; they're just electrons. I'll leave it to you to look up the constituent parts of protons; they have individual charges within themselves.

The actual reason that one is positive and one is negative is slightly more tricky. If that's the answer that you're looking for you need to perhaps ask a more specific question.

  • $\begingroup$ News to me. What would those reasons be? It's just a matter of convention, elementary or otherwise. (See what I did there) $\endgroup$ Commented Oct 6, 2015 at 13:25
  • $\begingroup$ Electrons are also made of multiples of quarks of magnitude $\frac{2}{3}$e and $\frac{1}{3}$e . But these quarks do not exist in nature. The electron does as a whole. Re-consider your point. $\endgroup$ Commented Oct 6, 2015 at 14:01
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    $\begingroup$ @Aniket I'm tempted to swear and blind and tell you to reconsider your own point, but I'll just politely ask you to point me to any reasonable source that says an electron (a lepton) is made up of quarks. Or alternatively, politely ask you to google what a lepton is. $\endgroup$
    – Matt
    Commented Oct 6, 2015 at 14:36
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    $\begingroup$ @Aniket - electrons are elementary particles - no quarks were harmed in their construction... $\endgroup$
    – Jon Custer
    Commented Oct 6, 2015 at 14:53
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    $\begingroup$ Let's be clear: electrons are not comprised of quarks. Full stop. $\endgroup$
    – garyp
    Commented Oct 6, 2015 at 15:05

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