This major revision of the world's leading textbook of physical chemistry has maintained its tradition of accessibility but authority and has brought it thoroughly up to date. The new author team has introduced many innovations. There are new or rewritten chapters on the solid state, on molecular interactions, macromolecules, and electron transfer. Almost every chapter has at least one Box showing the relevance of the material to modern chemistry. All the chapters now conclude with a check list which includes definitions and key equations. The authors have paid special attention to the presentation of mathematical derivations and to the physical interpretation of equations. They have also ensured that the text is highly modular, so that it can be used in different sequences, either atoms first or thermodynamics first. The art program has been redrawn and extended, new Discussion questions have been added, and the Further Information sections have been recast to provide the necessary background in mathematics and physics. The text is fully geared to the web, with full media support.