A unique introductory text on quantum mechanics, from basic principles to historical perspective. * Includes description of the historical developments that led to the discovery of QM, often left out of other textbooks. * Emphasizes basic concepts that were essential in this discovery, placing them in context and making them more understandable to students. * Written in an easy-to-understand style and assuming no prior knowledge of the topic, this book provides a solid foundation for future study of quantum chemistry. * Includes problem sets for student use.