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Dedicated to Glenn T. Seaborg
Dedicated to
G L E N N T. S E A B O R G
Among the many noteworthy scientific achievements of the 20th century, there are only a very few that can match the discovery of the actinide elements in its impact on science and society. The addition of an entire new family of largely man-made elements to the Periodic Table, and the formulation of the actinide concept have had a profound influence on the way physicists and chemists think about the electronic structures of the elements. The new insights arising from studies on the chemistry and physics of the heaviest elements has had an especially important influence on the way we think about the more familiar elements of the Periodic Table, in particular, the rare earths. In the saga of the actinide elements, Glenn Seaborg has been the pivotal figure. The dedication to Glenn Seaborg of these volumes of the Handbook on the Physics and Chemistry of Rare Earths, which deal with the relationships of the lanthanide and actinide elements, is thus a fitting recognition of the exceptionally important contribution that his actinide element studies have made to many branches of science. Glenn Seaborg's scientific career began in the 1930's as a research associate of G.N. Lewis at the University of California. He early became convinced that the science of nuclear chemistry, then in its infancy, provided challenging opportunities for scientific discovery. In the Lawrence Radiation Laboratory, in the course of a few years, he validated his intuition by the discovery of a host of isotopes, m a n y of which have become important in research and medicine. Among these are cobalt-60, iodine-131, technetium-99m, cesium-137, and, of course, the plutonium isotopes. In 1944, he formulated the actinide concept of heavy-element electronic structure that accurately predicted the existence of a family of rare earth-like elements at the end of the Periodic Table as it was generally presented at that time. The actinide concept was the guide to the discovery of the remaining members of the actinide elements. In addition to the fissile plutonium isotopes, he and his co-workers over the years discovered no less than nine additional members of the new rare earth-like family of elements. These discoveries have been of great relevance not only to purely scientific matters but also to such global problems as nuclear energy and the control of nuclear weapons. In addition to his life as an active scientist, Glenn Seaborg has had a distinguished career in academic and public life. He served at various times as Chancellor of the University of California at Berkeley, Chairman of the Atomic Energy Commission for a period of ten years, and Chairman of the Lawrence Hall of Science, to name only a few of his extra-scientific activities. He was the recipient of a Nobel Prize (1951) for his discoveries in the chemistry of the transuranium elements, and has received encomiums from most of the scientific societies of the world. ix
x
DEDICATION
In spite of worldly distractions, Glenn Seaborg has never wavered in his life-long commitment to science. He continues his research into the chemistry and nuclear systematics of the actinide elements. Recently, he has focused his attention on the possible existence of still another family of superheavy elements at the end of the Periodic Table, and the development of new methods for the synthesis of superheavy elements. The dedication of these volumes to Glenn Seaborg is not only a testimonial to his scientific achievementsi it is also an appreciation of the example that he continues to set.
G L E N N T. S E A B O R G
Among the many noteworthy scientific achievements of the 20th century, there are only a very few that can match the discovery of the actinide elements in its impact on science and society. The addition of an entire new family of largely man-made elements to the Periodic Table, and the formulation of the actinide concept have had a profound influence on the way physicists and chemists think about the electronic structures of the elements. The new insights arising from studies on the chemistry and physics of the heaviest elements has had an especially important influence on the way we think about the more familiar elements of the Periodic Table, in particular, the rare earths. In the saga of the actinide elements, Glenn Seaborg has been the pivotal figure. The dedication to Glenn Seaborg of these volumes of the Handbook on the Physics and Chemistry of Rare Earths, which deal with the relationships of the lanthanide and actinide elements, is thus a fitting recognition of the exceptionally important contribution that his actinide element studies have made to many branches of science. Glenn Seaborg's scientific career began in the 1930's as a research associate of G.N. Lewis at the University of California. He early became convinced that the science of nuclear chemistry, then in its infancy, provided challenging opportunities for scientific discovery. In the Lawrence Radiation Laboratory, in the course of a few years, he validated his intuition by the discovery of a host of isotopes, m a n y of which have become important in research and medicine. Among these are cobalt-60, iodine-131, technetium-99m, cesium-137, and, of course, the plutonium isotopes. In 1944, he formulated the actinide concept of heavy-element electronic structure that accurately predicted the existence of a family of rare earth-like elements at the end of the Periodic Table as it was generally presented at that time. The actinide concept was the guide to the discovery of the remaining members of the actinide elements. In addition to the fissile plutonium isotopes, he and his co-workers over the years discovered no less than nine additional members of the new rare earth-like family of elements. These discoveries have been of great relevance not only to purely scientific matters but also to such global problems as nuclear energy and the control of nuclear weapons. In addition to his life as an active scientist, Glenn Seaborg has had a distinguished career in academic and public life. He served at various times as Chancellor of the University of California at Berkeley, Chairman of the Atomic Energy Commission for a period of ten years, and Chairman of the Lawrence Hall of Science, to name only a few of his extra-scientific activities. He was the recipient of a Nobel Prize (1951) for his discoveries in the chemistry of the transuranium elements, and has received encomiums from most of the scientific societies of the world. ix
x
DEDICATION
In spite of worldly distractions, Glenn Seaborg has never wavered in his life-long commitment to science. He continues his research into the chemistry and nuclear systematics of the actinide elements. Recently, he has focused his attention on the possible existence of still another family of superheavy elements at the end of the Periodic Table, and the development of new methods for the synthesis of superheavy elements. The dedication of these volumes to Glenn Seaborg is not only a testimonial to his scientific achievementsi it is also an appreciation of the example that he continues to set.