The third edition of this text has been completely rewritten and revised. The author provides more coverage of solid and liquid states than is found in other texts on this subject, and introduces topics such as computer simulation and quasicrystals. Each chapter concludes with a set of problems and detailed solutions designed to help the reader become familiar with the subject and its applications. Additionally, computer programs specifically designed to assist the reader may be downloaded from the World Wide Web. This modern text on physical chemistry will be of interest to undergraduate students in chemistry, as well as students in other areas of science and engineering who are required to have a familiarity with the subject.