Randall B. Shirts, Brigham Young University

Boltzmann is designed to help students understand the principles of kinetic molecular theory by demonstrating molecular motion, statistical mechanics and other fundamental theories of chemistry and physics.

The display area is an "arena" in which as many as 200 atoms move and collide with each other. The arena may be viewed as a single area or divided into two regions in which the same or two different sizes (masses) of atoms may be displayed. This dynamic display helps students visualize the effects of changing the number of atoms, their mass, radius or temperature.

The screen also contains a field which displays any of twelve different graphs of the behavior of the atoms. These histograms plot instantaneous and average speed, RMS velocity, and average RMS velocity, kinetic energy and average kinetic energy, X and Y velocity, average path, time collision and collision rate in several different formats.

Boltzmann can be used as a classroom demonstration tool or as a self-directed student exploration in a variety of classes from freshman chemistry to graduate level statistical mechanics. It is a unique software tool which can be used to effectively demonstrate:

• distribution of molecular velocities
• gas laws
• the nature of pressure, diffusion, and effusion
• molecular collisions and collision rates
• free path distribution
• heating and cooling

Its convenient, versatile user interface may be operated by either mouse or keyboard. Demonstrations may be saved, and detailed histories, averages and distributions can be written as data files.

"The response of the students was enthusiastic, with written comments including, 'I wish we could have had this last year', 'The visual aid is like a second dimension for the lecture' and 'I think it is a great way to learn - almost entertaining!' I...would certainly recommend anyone teaching first-year physical chemistry to give it a trial." Hugh Powell, University of Adelaide, in UniServe Science News, July 1996.