Reading Time: < 1 minute


Heating and cooling substance may bring about one or more physical changes in a substance as a result of a change in the energy content of the particles the substance is made up of. The particular changes in energy of a particle in the sample of substance may be either kinetic or potential energy or both. Kinetic and potential energy of a particle is a function of its motion and position relative to the other particles surrounding it. Energy change (whether kinetic and/or potential) in the particles of a sample of substance is accompanied by changes in Entropy as a whole. Regardless of the change, changes in the motion of particles can be at times be dramatically demonstrated.

M4 Chemistry Matter II: State and Energy. PowerPoint slides on the relationship between state of matter and energy content of particles in a sample of the matter.

Discrepant Event

The video below shows three different demonstrations looking at the effect of cooling a squash ball, a rose and a small balloon filled with air using liquid nitrogen. Watch the video to see what happens.

And the questions are:

  1. Why did the squash ball and the rose shatter like glass?
  2. Why did the balloon deflate when introduced into liquid nitrogen and then spontaneously re-inflate when taken out?

Concepts involved:

  • cooling, heating, heat, energy/heat transfer/exchange,  pressure, temperature.
  • entropy, energy content, energy (enthalpy) and state, motion of particles, speed of particles.
  • (Additional concepts: degree of freedom, vibrational motion, rotational motion, translational motion)

Facebook Comments (see farther below for other comments)


Don't leave me hanging...say something....

This site uses Akismet to reduce spam. Learn how your comment data is processed.