Energy in Chemical Systems: An Integrated Approach

Abstract

“Energy” is a complex scientific concept central to all scientific disciplines. Here we describe three perspectives often used to address energy in the context of introductory college level courses: the macroscopic, which involves thermodynamic and mathematical treatments of energy and energy changes, the atomic-molecular, which relates to energy changes that result from bonding and intermolecular interactions, and the quantum-mechanical, which relates to energy quantization and provides the basis for understanding periodic trends, molecular structure, and electromagnetic radiation. A robust understanding of the role of energy within chemical systems requires that these three perspectives be integrated, but often they are separated into distinct sections of the course and are not explicitly connected. Moreover, prior instruction that does not explicitly address energy concepts at the molecular level almost certainly adds to student challenges. We suggest an alternate approach, illustrated by the new general chemistry course “Chemistry, Life, the Universe and Everything”, in which structure, properties and energy are presented as three interconnected learning progressions, and the treatment of energy is integrated. All three energy perspectives are explicitly addressed and related to each other in increasingly more sophisticated ways, so that students are led from the structure of the atom through to networked biological reactions, and the role that energy, entropy and Gibbs energy play in these systems.