Hands-on Model for Investigating Entropy and Disorder in the Classroom

A sound understanding of entropy is essential for any rounded education in thermodynamics and many other disciplines of physical science. However, students with a poor understanding of this important topic may be found across all education levels, often conflating entropy with disorder. Many teachers wish to instill an understanding of the quantitative definition of entropy—a function of the number of accessible energy states (Fig. 1). This demonstration explains entropy in a visually interesting manner, using handheld containers of simple objects to model entropically driven processes in systems of noninteracting particles. Within the containers, a spontaneous increase of entropy results in increased visual order, consistent with an increase in the number of available energy states. A failure of the notion that entropy is disorder is also exposed. Because the demo models microscopic particles directly, no analogy is required to translate conclusions into “real” systems. After activities involving these models, students...