ABSTRACT
Energy is a foundational concept that explains and connects scientific phenomena. In chemistry, the energy of a system changes during physical and chemical reactions. In this chapter, readers are introduced to the fundamentals of kinetic and potential energy: The kinetic energy of particles relates to the temperature of a system, and the potential energy is the energy of a system's configuration. Attention is given to ensuring that readers have a clear sense of terminology, especially in terms of the direction of energy transfer, from system to surroundings or vice versa. We then consider these intangible concepts in the context of real-world, macroscopic examples. After considering the macroscopic examples, we delve into how these energy ideas relate to the nanoscopic world of chemistry. Heat and work, energy transfer between the system and the surroundings, are the fundamental tools that we use to understand these phenomena, which are related to the change in internal energy (∆U).
