Experiments in diffusion: gases, liquids, and solids for under five dollars

Abstract

Differences in velocities of diffusing species of solids, liquids, and gases can capture the imagination of students of all ages. Using common utensils, host materials, and diffusing media, along with some ingenuity and novelty in team efforts, students can measure the actual velocities of diffusing solids, liquids, and gases, and have fun in the process. There is no need for high temperatures such as are needed to observe these processes in steels, oxides, and the like. By increasing temperature, pressure, and kinetic energy of the molecules, students may study these phenomena at whatever level of involvement they deem necessary in these three experiments. They can apply graded levels of mathematics for the analyses of these data. The comments and variations are encouraging to the professor, and the basic principles of diffusion are retained for longer periods of time than from 'conventional wisdom' pedagogy. These experiments work very well with middle school as well as college students. The comments are very positive to date.