Discovering the Behavior of Gases

These are a series of movie (avi) files, so it is a slow load!  The movie images do NOT print!

What do you observe different for helium at 100K and 400K?  One particle leaves a trail, the red line, as it moves about.  Why does the trail change directions?

Helium at 100 K                             Helium at 400 K

How does neon compare to helium at the same temperatures- 400K?  Why?

Neon at 400 K                                     Helium at 400 K

What do you notice about the helium atoms and neon atoms in a container (on the left below) at the same temperature?  Why?

What happens when the helium is compressed to a smaller volume (container on right)?  Why are gases very compressible?


Helium and neon mixed                            Pressure increase on helium

How does the concentration of helium influence its behavior?  The average length of the red line is the mean free path of the helium.  How does the mean free path change with concentration?  Why?

Helium at low concentration                  Helium at high concentration

Particle simulations from Dr. John I. Gelder, Kirk Haines, and Dr. Mike Abraham
Dept. of Chemistry, Oklahoma State University and University of Oklahoma:
(click above to open this MERLOT award winning simulation in a new window)
You can adjust variables to see the influence on the gas particles.
Graphical display of variables is also available.

Click here for a pdf handout to use with this simulation.

Movies produced using RenderSoft CamStudio: 
A great piece of freeware!

Scott A. Sinex            Prince George's Community College            March 2003