Thermodynamics is the physics of heat, mechanical energy or work, and the conversion of one into the other. All systems follow the laws of thermodynamics and since almost all energy production is based on thermodynamics, it is important to understand the laws. The demonstrations presented In this chapter will help to do this. Teacher background information, assessment, safety notes, and references are provided. This book selection also includes the Table of Contents, About the Authors, An Introduction to Phenomenon-based Learning, Appendix, Credits, and Index.