I came across this following question while poring over my textbook.

Predict the change in the motion of particles you would expect in the following if the temperature was increased:
a) Solid
b) Liquid

I think if the temperature increases, solid or even liquid particles will receive more energy and therefore their motion will speed up. I'm not sure why there are two parts for this question. Aren't they supposed to be similar?

Thank you so much for helping! Since this is my first post, please pardon me if I accidentally violate any rules of the forum.

  • 1
    $\begingroup$ related: physics.stackexchange.com/q/113643 $\endgroup$
    – A.K.
    Feb 9, 2019 at 3:30
  • $\begingroup$ @A.K. Thanks for the link, Physics.SE delivers big time :) I don't think there is a straightforward answer to this one (well, at least not if treating this as a HW question where a student is supposed to give a simple answer), and it would be interesting to receive some answers first, and not close the question as an off-topic. $\endgroup$
    – andselisk
    Feb 9, 2019 at 3:55
  • $\begingroup$ I am surprised the no respondent mentioned sulfur. A little above its melting point it's a mobile liquid but as you heat it up it undergoes a chemical reaction that results in an allotrope with long chains that is more like thick tar in consistency. Thus although the individual sulfur atoms may be oscillating more strongly about their average positions as they heat up, their capacity to move freely through the bulk material becomes sharply restricted. $\endgroup$ Feb 9, 2019 at 15:38
  • $\begingroup$ @andselisk I was not implying that it was a duplicate, I only wanted to link a question that was related to the current one. $\endgroup$
    – A.K.
    Feb 10, 2019 at 18:31
  • $\begingroup$ @A.K. Neither was I, I haven't voted to close the question, I suggested not to close the question. Sorry if it wasn't clear. $\endgroup$
    – andselisk
    Feb 10, 2019 at 18:33

1 Answer 1


Indeed they are similar, but there is a difference. For solids, particles can only vibrate about their own position. Heating results in a stronger vibration. For liquids, particles can wander around the whole volume of the liquid. Heating increases the speed of the particles so that they can move more quickly inside the liquid, hence a higher diffusion constant.


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.