Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Why or How an electron REVOLVE around the Atom ?

  1. Feb 29, 2008 #1


    User Avatar

    how electron do this work infinity?
    where the energy come from for this work?
    It thus violates the law of conservation of energy.
    ((please answer and teach me))
  2. jcsd
  3. Feb 29, 2008 #2

    Doc Al

    User Avatar

    Staff: Mentor

    Realize that a picture of electrons orbiting the nucleus is a semi-classical approximation, at best. Are you asking about radiation losses?
  4. Feb 29, 2008 #3


    User Avatar

    I asking about this:

    How an electron rotate around the proton ?
    The electron need energy for REVOLVE around the Atom
    Where the energy of rotating come from ???
  5. Feb 29, 2008 #4

    Doc Al

    User Avatar

    Staff: Mentor

    And I'm asking: What makes you think the electron needs energy to revolve around the nucleus?

    For example: Does the earth need energy to revolve around the sun?

    I'm just checking the level of answer you want.
  6. Mar 1, 2008 #5


    User Avatar

    We can not prevent from electron rotating
    But with a small FRICTION we can prevent from earth rotating around the sun ...

  7. Mar 1, 2008 #6

    Though I somewhat feel incapable of catching up with the thread of this coversation and the comparison to earth and sun appears more to be a joke to me:

    Will you rephrase what makes you think the "electron-proton system" is different from the "earth-sun system". What friction? Prevent what?

    (at least a thread which doesnt require me to have a physics major to understand it :-D)
  8. Mar 1, 2008 #7


    User Avatar

    dear sir please attention to :

    The earth REVOLVE around the sun for this reason : Einstein Relativity
    But the reason of electron rotating is ... ??????????
  9. Mar 1, 2008 #8

    Don't you think you start mixing things there up a little bit? As for the comparison by Doc Al, consider the following:

    Electron-Nucleus: Electromagnetic Forces
    Earth-Sun: Gravitational Forces
  10. Mar 1, 2008 #9


    User Avatar

    please say the reason of electron rotating to me .....
  11. Mar 1, 2008 #10
    I can't bring it down to one point in a single post. Neither do I think that I could fully explain it anyway. But that's far more ellaborate than you'd imagine. As Doc Al correctly mentioned before, we first should be aware of the level of complexity you actually want.

    There are many different ways to explain the one or another thing. Each way comes with its specific advantages and flaws. As for the atomic structure you could, for instace, consult archaic ideas such as Bohr's atomic mode where the electron just revolves the nucleus like the earth would the sun, or you could try to go far beyond this and explain it in terms of quantum physics where the electron is not just an electron any longer but instead a wave.
    If you are still not satisfied you could consider QED and QCD where the electron is not a wave any longer but is made up of tiny particles which describe fundamental relationships.

    But for all this, don't ask me. I'm not even a student of physics.
  12. Mar 1, 2008 #11


    User Avatar
    Science Advisor

    Someone tells you you are wrong so you insult them?

    No, the earth does NOT revolve around the sun because of "Einstein Relativity". By classical physics, if the earth did not rotate around the sun, it could not avoid being pulled into the sun by gravity. Except for minor details the rotation of the planets is fully described by Newtonian physics and relativity is not needed at all.

    You have already been told two things:

    In classical physics, the electron rotates around the nucleus, the Bohr "planetary model" for exactly the same reason the earth rotates around the sun. But you simply deny that.

    In quantum physics, the electron does NOT rotate around the nucleus so there is no question.
  13. Mar 1, 2008 #12
    This question has been asked over and over again. Thats why we wrote the explanation into our FAQ : https://www.physicsforums.com/showpost.php?p=862093&postcount=2 [Broken]

    Last edited by a moderator: May 3, 2017
  14. Mar 1, 2008 #13


    Staff: Mentor

    Hi mhd,

    As others already mentioned, electrons do not orbit, rotate, or revolve around an atom. They occupy fixed orbitals.

    However, you should be aware that in general no energy is required to maintain rotational motion. The conservation of angular momentum requires that a rotating system continue rotating indefinitely unless acted on by some external force. An external force can do work on a rotating system to increase its rotation and thereby add some kinetic energy, or the rotating system can do work on an external body to decrease its rotation and thereby lose some kinetic energy. But energy input is not required to maintain constant angular momentum.
  15. Mar 1, 2008 #14


    User Avatar
    Science Advisor
    Homework Helper

    no loss of energy

    Hi mhd! Welcome to PF! :smile:

    No, it neither gains nor loses energy.

    This is because it stays the same distance from the proton.

    It's like a flywheel rotating (on a stationary axis) - if there's no friction, then there's no loss of energy, and the flywheel will keep going at the same rate forever.

    Does that help? :smile:
  16. Mar 1, 2008 #15
    Guys, the question has been solved ! No need to keep regurgitating the same answer over and over again.

Share this great discussion with others via Reddit, Google+, Twitter, or Facebook