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Inertia and Quantum physics

  1. Jun 5, 2013 #1
    Dear all,

    correct my understanding... Inertia should be applicable at sub atomic level as well. right ?
    Consider this scenario, a positively charged helium ion is accelerating. the electron cloud in this case should be somewhat oval or elliptical right ? this would be because, the electric charge is uneven in the ion and the ion is accelerating... this would cause the electron cloud to form an oval shape..
  2. jcsd
  3. Jun 5, 2013 #2


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    Presumably you're talking about a singly charged Helium ion, in which the nucleus has charge +2, one electron is missing and the remaining one is in the ground state.

    You don't say how the ion is being accelerated, and it makes a difference. For example if it's falling in a gravitational field, the equivalence principle tells us the ion suffers no distortion at all. More likely since it's charged, you're accelerating it with an electric field. The effect that a uniform external field has on an atom is known as the Stark effect. Qualitatively what happens is that the atom becomes polarized - that is it develops an electric dipole moment. The positively charged nucleus is pulled in one direction while the negatively charged electron is pulled in the other. Rather than the acceleration, I'm talking about the force, but it's all the same.

    I'm afraid your intuition is incorrect, the electron's orbital would not become football-shaped, which would imply a quadrupole moment. Rather the atom develops a dipole moment.
  4. Jun 7, 2013 #3
    Thanks Bill for the explanation... you mentioned about atom being polarized in uniform electric field (atom is still accelerating) and hence takes elongated shape rather than a circle.. what i was thinking is..the inertia might also have some effect in distorting the shape ?
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