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How do electrons revolve around in molecule bonded by covalent bonds?

  1. Sep 26, 2011 #1
    How do electrons revolve around in molecule bonded by covalent bonds? An electron revolves around one nucleus. But if it is going to be shared by another nucleus(as in covalent bond), then how will the electron revolve? does it go all around both the nucleus? Please explain a little deeply.
  2. jcsd
  3. Sep 26, 2011 #2


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    Staff: Mentor

    It doesn't.

    Planetary model is only a... model. One that explains some of the observed properties, but it has not much to do with the reality. Electrons in atom or molecule don't behave like a point particles, they behave like waves. They are not in any particular position, so they can't change their position, as planetary model suggests.
  4. Sep 28, 2011 #3
    The electron is shared by both atoms so you can say that it spends some time around one atom and some time around the other.
  5. Oct 6, 2011 #4


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    Science Advisor

    In the case of the [itex]\mathrm{H_2^+}[/itex] molecular ion, the electron in a classical model would move on an elipsis around both electrons with the two H nuclei in the foci of the elipsis.
  6. Oct 6, 2011 #5
    The electron does not spend time because it does not move in the classical sense. You should simply think of a single electron as a fuzzy cloud and be satisfied with that mainly. It has a probability of being in a certain volume of space, which means it has a probability density at a point in space. The probability does not change with time. It does however oscillate at a characteristic frequency so that there is a phase difference between its conjugate properties. Therefore are the spatial volume becomes more defined as in parts of an orbital, the momentum of the electron within that area correspondingly becomes less defined. The electron also has quantum behaviour in that it may be in several places at once, by a process called "exchange". Such behaviour is called "delocalisation". This means that the energy of a chemical bond is not just the net electrostatic effect of the nucleus pulling on the electron "cloud", there is this "exchange energy" which is purely quantum mechanical. Also don't forget that the lobes of an orbital may be outside of the center of a chemical bond, so that some of the effect of these anti-bonding contributions may be to pull the bond apart to some degree.
  7. Oct 6, 2011 #6
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