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Relationship between molecular momentum and electron orbital behavior

  1. Jun 27, 2010 #1
    I don't know if this is a thermodynamics issue or a quantum mechanics one. It seems like there should be some relationship between the average heat and pressure of a system and the behavior of electrons orbiting nuclei. Does anyone know if there are any observations and experiments that have established differences in molecular behavior in different gravity situations? It seems to me that the average energy level of atomic electrons should be lower in lower gravity b/c of the reduced gravitational force determining pressure, but I can't figure out if there would be a way to measure this and I don't know what to google to research it.
  2. jcsd
  3. Jun 27, 2010 #2
    Why would it be lower? The gravitational forces of a nuclei, regardless of how small, should be the same unless you somehow change the mass or gravitational constant.

    But even if there was some effect the electromagnetic force is much stronger than gravitational forces.

    Unless you're somehow referencing tidal forces which are not really an issue since the size of an atom is very small.
  4. Jun 27, 2010 #3
    I'm not talking about gravity between the atomic particles themselves. I'm talking about gravity having an effect on the heat-pressure ratio of a system, which would increase and possibly intensify the frequency of molecular collisions. This in turn, I would think, would impart more average momentum into the orbiting electrons, which in turn would affect their behavior.

    In other words, the attractive force between the nucleus and the electrons would be the same, but the electrons would receive more KE more often from collisions with other molecules. This, I would think, would be a mechanism through which planetary gravity would affect the energy-levels of electrons orbiting a nucleus.
  5. Jun 28, 2010 #4


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    Not much of a relationship. It's only explicitly needed to understand the deviation from ideal gas behavior.

    There are no such observations, because the effect of gravity on electronic structure is far too small to be measured.
  6. Jun 28, 2010 #5
    Why is this?

    Do you mean the DIRECT effect of gravity, or the effect of gravity in determining the overall pressure/density of a system?

    Have there been experiments to measure electron position in lower or higher gravity situations? What about under different pressure conditions?

    I guess if the effect of the Earth's gravity is not that significant at the level of individual molecules, there would be no difference between increasing pressure through gravity and doing so by containing the system and reducing the volume?

    I assume that molecular KE does have an effect on electron orbit motion insofar as certain levels of heat induce chemical reactions or phase changes. I've read that water boils (and freezes?) at temperatures other than 100/0 C depending on altitude. Is this due to atmospheric pressure, gravity, or both? Have other differences in chemical behavior been observed besides phase-changes in water?
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