Skip to main content
Physics

You are not logged in. Your edit will be placed in a queue until it is peer reviewed.

We welcome edits that make the post easier to understand and more valuable for readers. Because community members review edits, please try to make the post substantially better than how you found it, for example, by fixing grammar or adding additional resources and hyperlinks.

6
  • $\begingroup$ Thanks Wood. In a closed system is there any chance to take all the molecules at the same level by adding heat? or will they follow any distribution ? $\endgroup$
    – mustang
    Commented Jun 4, 2018 at 4:49
  • $\begingroup$ Hello! I need your help to understand the part about the small change in populations of energy levels. For your answer, I am thinking of a gas undergoing pressure vs heating. What would be the difference? Would it be hard to add examples to your answer? All the best, thank you ;) $\endgroup$
    – Curious Watcher
    Commented Aug 18, 2021 at 21:23
  • $\begingroup$ A simple example: A particle (modelling an ideal gas) in a cuboidal box of side lengths $a$, $b$, $c$ can only have energies given by $E=\frac{h^2}{8m}\left(\frac{n_x^2}{a^2}+\frac{n_y^2}{b^2}+\frac{n_z^2}{c^2}\right)$. $n_x$, $n_y$, $n_z$ are integers. If we do work slowly on the gas by pushing in a piston we reduce $a$, $b$ or $c$ so we increase the energy of any given level, as identified by a given set of integers $n_x,\ n_y,\ n_z$. We don't alter the populations of the levels. But if we feed in heat we don't alter the shape of the box, so we don't alter the energy levels. $\endgroup$
    – Philip Wood
    Commented Aug 18, 2021 at 22:33
  • $\begingroup$ But we do alter the distribution of particles in the various energy levels. @Curious Watcher $\endgroup$
    – Philip Wood
    Commented Aug 20, 2021 at 10:58
  • $\begingroup$ Amazing, thank you for an update, definitely adds weight. And me, I am still working on understanding this, my internal video card is still processing the visualization on energy levels, are we talking of the energy levels as in internal energy levels, starting from 0 and marked as integers? I have doubts and no better way at the moment than to ask, thank you for your patience. $\endgroup$
    – Curious Watcher
    Commented Aug 23, 2021 at 19:15