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B A question about conduction...

  1. Feb 8, 2017 #1
    Okay...It is written so often, even in the kinetic molecular model, that molecules of a substance (or atoms) collide with each other...so what does the collision of an atom actually mean, like at an atomic level...Do atoms get close to each other so that their electrons repel each other???....Also how does this "collision" generate energy??? Is there an absorption of a photon by electrons???
  2. jcsd
  3. Feb 8, 2017 #2


    Staff: Mentor

    Yes atoms and molecules can get close and collide.

    Collisions conserve energy, they do not generate energy.

    Yes, electrons absorb, scatter, and emit photons.
  4. Feb 8, 2017 #3


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    Staff: Mentor

    What kind of conduction are we talking about? Heat or electrical?
  5. Feb 9, 2017 #4
    My question was that what is meant by this 'collision'', does it mean the orbitals overlap, or do the individual atoms repepl each other...???
  6. Feb 9, 2017 #5


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    Staff Emeritus
    Science Advisor
    Education Advisor

    Your question does not match the title you have created for this thread. So that already created a lot of confusion. Maybe you don't realize what "conduction" actually mean.

    Your question about "collision" has more to do on what is meant by our use of the term "touching" at the atomic/molecular level. Please note that the explanation can be quite different for "bare" atoms, particles, or molecules versus solids, since in the latter, surface physics may play a significant role.

    We already have many threads on the "physics of touching". You may want to do a quick search for it.

  7. Feb 9, 2017 #6


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    Staff: Mentor

    My understanding:

    Orbitals don't have a set size. They actually extend outwards to an infinite distance. The images of the orbitals you see have truncated the orbitals to show the most likely locations of the electron. Often they show the region where the electron has a greater than 50% chance of being found.

    In a collision, the atoms get so close that the repulsion by their electrons rises very quickly, decelerating them and then forcing them apart. Once they are far apart (relative to their size) the repulsion is essentially zero.

    It doesn't generate energy unless it causes the atoms/molecules to undergo an exothermic chemical reaction and release energy.

    During a collision? No, not unless there happened to be a photon passing through at exactly the right time.
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