Suitable for advanced undergraduates, this thorough text focuses on the role of symmetry operations and the essentially algebraic structure of quantum-mechanical theory. Based on courses in quantum mechanics taught by the authors, the treatment provides numerous problems that require applications of theory and serve to supplement the textual material. Starting with a historical introduction to the origins of quantum theory, the book advances to discussions of the foundations of wave mechanics, wave packets and the uncertainty principle, and an examination of the Schrödinger equation that includes a selection of one-dimensional problems. Subsequent topics include operators and eigenfunctions, scattering theory, matrix mechanics, angular momentum and spin, and perturbation theory. The text concludes with a brief treatment of identical particles and a helpful Appendix.