German Chemist, born on March 8, 1879 in Frankfurt, Germany. He began undergraduate studies in chemistry 1897, at Marburg and Munich, receiving his doctorate in 1901, with a thesis on organic chemistry. He was initially set on a career in industry, however, he remained at the Chemical Institute in Munich for two years after he finished. Shortly after, in the autumn of 1902 and the summer after, he went to England to work under Sir William Ramsay at University College, London, who had earlier discovered most of the noble gases. There, he identified "radiothorium" (which we now know to be thorium-228) while working on special radium salts, and changed his mind about his career, becoming a lifelong academician and researcher. Immediately after, he was at the Physical Institute at Montreal, Canada, where he stayed for a similar amount of time under Professor Ernest Rutherford, where he prepared radioactinium and did further research in nuclear chemistry. He returned to Germany in 1906, to the Chemical Institute of the University of Berlin, where in spring of the following year he qualified as a university lecturer.
At the end of 1907 Dr. Lise Meitner came to Berlin from Vienna, and the two of them began a collaboration that would last thirty years. Their work at the time focused on the study of beta particles, particularly on their use as agents in nuclear transformations. In 1911 he became a member of the prestigious Kaiser Wilhelm Institute for Chemistry, and in 1913 was married to Edith Junghans, who bore him a son named Hanno in 1922.
During 1914 to 1918 Hahn and Meitner's work was briefly interrupted while Hahn served in World War I, but after war's end he resumed work with Dr. Meitner, and together they discovered a new element, protactinium, the long-lived mother element of the actinide series of elements, and in 1928, became the director of the Kaiser Wilhelm Institute for Chemistry, a post he held until 1944.
After James Chadwick discovered the neutron in 1932, it was immediately understood throughout the scientific community at the time that this new sub-atomic particle would be a very useful tool for unlocking the secrets of the atom, and Hahn, Meitner, and their collaborator Dr. Fritz Strassman were not slow to recognize this fact. They were experimenting with these particles carefully, attempting to create new transuranic elements by bombarding various lighter elements such as uranium and thorium with neutrons, and examining the results. In 1938, as the Nazis were beginning to close on people of Jewish descent, Lise Meitner left Germany for the Nobel Institute in Stockholm, leaving Hahn and Strassman to continue their research. Shortly after her departure, Hahn and Strassman found that in their attempts at bombarding uranium with neutrons they unexpectedly produced barium, a much lighter element. They immediately reported this strange event to Meitner, who interpreted it, with the help of her nephew Otto Frisch, as the nuclear fission of the uranium, using Niels Bohr's liquid drop model of the atomic nucleus. On hearing of this discovery, Bohr immediately went to bring news of this discovery to the United States in 1939, just months before World War II began, where its military possibilities were immediately recognized, and ultimately resulted in the Manhattan Project.
During the war years, neither Hahn, Strassman, nor Meitner had engaged in nuclear weapons research. At the end of the war, Hahn was astonished to learn that he had been awarded the Nobel Prize in Chemistry in 1944 (an award many believed he should have shared with Meitner), and that their discovery had led to the creation of nuclear weapons. Later, as Director of the Kaiser Wilhelm, later Max Planck Gesellschaft, he had been a vocal speaker against the misuse of nuclear energy. He died in 1968. Element 105, Hahnium, is named in his honor.
Sources:
Beiser, Arthur, Concepts of Modern Physics, Fifth Edition, New York: McGraw-Hill, Inc., 1995.
Nobel Prizes in Chemistry, 1944, at http://www.nobel.se/
"Otto Hahn, Fritz Strassman, and Lise Meitner", at http://www.chemheritage.org/EducationalServices/chemach/ans/hms.html.
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