Niels Bohr and the Quantum Atom gives a comprehensive account of the birth, development, and decline of Bohr's atomic theory. It presents the theory in a broad context which includes not only its technical aspects, but also its reception, dissemination, and applications in both physics and chemistry.

1. Atomic theory before 1913 ; 2. On the constitution of atoms and molecules ; 3. Reception and early developments ; 4. The Bohr-Sommerfeld theory ; 5. A magic wand ; 6. Molecules and other failures ; 7. A theory of the chemical elements ; 8. The end of the Bohr atom ; 9. Appendix: The philosophers' atom

`Review from previous edition This book is likely to become the definitive history of the development of Bohr's atomic model. Written by an experienced historian of science, it surveys the full breadth of the literature on its history and implications in physics, chemistry, astrophysics and far beyond, including excerpts from many still unpublished sources such as letters or manuscripts.' Klaus Hentschel, Professor and Director of the History Department, Stuttgart University `This compelling biography of a scientific theory, that of the Bohr atom, is unprecedented and unmatched in depth and breadth. It explores the development of the revolutionary Bohr atom from its birth in 1913 and extensions during the next five years to its supersession by modern quantum mechanics in the mid 1920s, treating at each stage its successes and failures and its positive and negative receptions in Europe and the United States. It is unique in emphasizing and documenting that Bohr conceived his theory as a comprehensive theory of the constitution of matter, one that applied to both atoms and molecules, that is, to the domains of both physics and chemistry, whose practitioners responded to it in profoundly different ways. We have here what promises to be the definitive history of the Bohr theory of the atom.' Roger H. Stuewer, History of Science and Technology, University of Minnesota `Around the world, the Bohr model of the atom is visually synonymous with "science." Despite its universality, the Bohr atom has waited a hundred years for Kragh's thorough study. Usually exiled to introductory chapters in histories of quantum mechanics, this instantly recognizable model has long needed a focused investigation. Kragh examines Bohr's atom on its own terms, not merely as a stepping-stone to later quantum theory. In this book we have a remarkable narrative of the genesis, application, reception, and use of one of the pivotal theories of modern physics.' Matthew Stanley, Gallatin School of Individualized Study, New York University

Presents for the first time a detailed and comprehensive study of the Bohr atom in all its aspects. By investigating the entire life of the theory, from birth to death, it provides a unique example of theory dynamics that will interest both historians and philosophers. Presents a broader picture of Bohr's atomic theory by taking into account the reception of the theory and the often critical voices of scientists of a conservative inclination. Discusses the chemical aspects of the theory as an integral part of it, which is rarely done in other accounts. Pays particular attention to the tests of Bohr's theory and the anomalies it faced, thereby giving a clearer picture of its decline and the crisis that led to quantum mechanics.

After graduation from the University of Copenhagen in physics and chemistry, and a period as a high school teacher, Helge Kragh became Associate Professor at Cornell University, Departments of History and Physics. Later, he took positions as Curator at the Steno Museum for Science and Medicine and Professor of the History of Science at the University of Oslo. Since 1997, he has been Professor of the History of Science and Technology at Aarhus University, Denmark. He is a member of the Royal Danish Academy of Sciences and Letters, the International Academy for History of Science, and the European Academy of Science. From 2008-2010, he was President of the European Society for History of Science.

Presents for the first time a detailed and comprehensive study of the Bohr atom in all its aspects. By investigating the entire life of the theory, from birth to death, it provides a unique example of theory dynamics that will interest both historians and philosophers. Presents a broader picture of Bohr's atomic theory by taking into account the reception of the theory and the often critical voices of scientists of a conservative inclination. Discusses the chemical aspects of the theory as an integral part of it, which is rarely done in other accounts. Pays particular attention to the tests of Bohr's theory and the anomalies it faced, thereby giving a clearer picture of its decline and the crisis that led to quantum mechanics.