This course emphasizes a core of material in the area of spectroscopy that is of importance to all chemists. Accordingly, the properties of individual atoms and molecules will be presented from the viewpoint of quantum mechanics. Whereas, the concepts of quantum mechanics can be developed into a powerful set of techniques for dealing with three basic types of motion: translation, vibration, and rotation. All these types of motion play an important role in chemistry because they are ways in which molecules can be store energy.