Introductory Chemistry Laboratory: Quantum Mechanics and Color

Abstract

Laboratory experiments provide students a tangible means of understanding dry, abstract concepts. A simple and engaging introductory wet chemistry laboratory has been developed relating quantum mechanics to color, which has been implemented for a class of about 600 students per academic year for over three years at Brown University. Color is an important aspect of daily life, used to communicate meaning and emotion. Nanoparticles, organic dyes, and metal complexes produce color in medieval stained glass, textiles, and gemstones, respectively. Though they can produce visually similar colors, the microscopic mechanisms of color production are different. The origins of color are used to facilitate the discussion of quantum mechanics and bonding concepts. The relation of these color producing model systems to chemical concepts also serves as motivation for an introduction of advanced concepts, such as nanochemistry, to first-year undergraduate students. Students synthesize silver nanoparticles of different shapes and sizes and use UV–vis spectrophotometers to characterize them along with additional unknown colorful solutions made from either metal complexes or organic dyes. Relating quantum mechanics and bonding to color in daily life excited students, promoting learning. This laboratory can be adapted for K–12 students.