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Harriet Hahn Biography & Facts

Otto Hahn (pronounced [ˈɔtoː ˈhaːn] ; 8 March 1879 – 28 July 1968) was a German chemist who was a pioneer in the fields of radioactivity and radiochemistry. He is referred to as the father of nuclear chemistry and father of nuclear fission. Hahn and Lise Meitner discovered radioactive isotopes of radium, thorium, protactinium and uranium. He also discovered the phenomena of atomic recoil and nuclear isomerism, and pioneered rubidium–strontium dating. In 1938, Hahn, Meitner and Fritz Strassmann discovered nuclear fission, for which Hahn alone, was awarded the 1944 Nobel Prize for Chemistry. Nuclear fission was the basis for nuclear reactors and nuclear weapons. A graduate of the University of Marburg, which awarded him a doctorate in 1901, Hahn studied under Sir William Ramsay at University College London and at McGill University in Montreal under Ernest Rutherford, where he discovered several new radioactive isotopes. He returned to Germany in 1906; Emil Fischer placed a former woodworking shop in the basement of the Chemical Institute at the University of Berlin at his disposal to use as a laboratory. Hahn completed his habilitation in the spring of 1907 and became a Privatdozent. In 1912, he became head of the Radioactivity Department of the newly founded Kaiser Wilhelm Institute for Chemistry. Working with the Austrian physicist Lise Meitner in the building that now bears their names, he made a series of groundbreaking discoveries, culminating with her isolation of the longest-lived isotope of protactinium in 1918. During World War I he served with a Landwehr regiment on the Western Front, and with the chemical warfare unit headed by Fritz Haber on the Western, Eastern and Italian fronts, earning the Iron Cross (2nd Class) for his part in the First Battle of Ypres. After the war he became the head of the Kaiser Wilhelm Institute for Chemistry, while remaining in charge of his own department. Between 1934 and 1938, he worked with Strassmann and Meitner on the study of isotopes created through the neutron bombardment of uranium and thorium, which led to the discovery of nuclear fission. He was an opponent of national socialism and the persecution of Jews by the Nazi Party that caused the removal of many of his colleagues, including Meitner, who was forced to flee Germany in 1938. During World War II, he worked on the German nuclear weapons program, cataloguing the fission products of uranium. As a consequence, at the end of the war he was arrested by the Allied forces; he was incarcerated in Farm Hall with nine other German scientists, from July 1945 to January 1946. Hahn served as the last president of the Kaiser Wilhelm Society for the Advancement of Science in 1946 and as the founding president of its successor, the Max Planck Society from 1948 to 1960. In 1959 he co-founded in Berlin the Federation of German Scientists, a non-governmental organization, which has been committed to the ideal of responsible science. As he worked to rebuild German science, he became one of the most influential and respected citizens of the post-war West Germany. Early life Otto Hahn was born in Frankfurt am Main on 8 March 1879, the youngest son of Heinrich Hahn (1845–1922), a prosperous glazier (and founder of the Glasbau Hahn company), and Charlotte Hahn née Giese (1845–1905). He had an older half-brother Karl, his mother's son from her previous marriage, and two older brothers, Heiner and Julius. The family lived above his father's workshop. The younger three boys were educated at Klinger Oberrealschule in Frankfurt. At the age of 15, he began to take a special interest in chemistry, and carried out simple experiments in the laundry room of the family home. His father wanted Otto to study architecture, as he had built or acquired several residential and business properties, but Otto persuaded him that his ambition was to become an industrial chemist. In 1897, after passing his Abitur, Hahn began to study chemistry at the University of Marburg. His subsidiary subjects were mathematics, physics, mineralogy and philosophy. Hahn joined the Students' Association of Natural Sciences and Medicine, a student fraternity and a forerunner of today's Landsmannschaft Nibelungi (Coburger Convent der akademischen Landsmannschaften und Turnerschaften). He spent his third and fourth semesters at the University of Munich, studying organic chemistry under Adolf von Baeyer, physical chemistry under Friedrich Wilhelm Muthmann, and inorganic chemistry under Karl Andreas Hofmann. In 1901, Hahn received his doctorate in Marburg for a dissertation entitled "On Bromine Derivates of Isoeugenol", a topic in classical organic chemistry. He completed his one-year military service (instead of the usual two because he had a doctorate) in the 81st Infantry Regiment, but unlike his brothers, did not apply for a commission. He then returned to the University of Marburg, where he worked for two years as assistant to his doctoral supervisor, Geheimrat professor Theodor Zincke. Discovery of radiothorium and other "new elements" Hahn's intention was still to work in industry. He received an offer of employment from Eugen Fischer, the director of Kalle & Co. (and the father of organic chemist Hans Fischer), but a condition of employment was that Hahn had to have lived in another country and have a reasonable command of another language. With this in mind, and to improve his knowledge of English, Hahn took up a post at University College London in 1904, working under Sir William Ramsay, who was known for having discovered the inert gases. Here Hahn worked on radiochemistry, at that time a very new field. In early 1905, in the course of his work with salts of radium, Hahn discovered a new substance he called radiothorium (thorium-228), which at that time was believed to be a new radioactive element. (In fact, it was an isotope of the known element thorium; the concept of an isotope, along with the term, was only coined in 1913, by the British chemist Frederick Soddy). Ramsay was enthusiastic when yet another new element was found in his institute, and he intended to announce the discovery in a correspondingly suitable way. In accordance with tradition this was done before the committee of the venerable Royal Society. At the session of the Royal Society on 16 March 1905 Ramsay communicated Hahn's discovery of radiothorium. The Daily Telegraph informed its readers: A new element – Very soon the scientific papers will be agog with a new discovery which has been added to the many brilliant triumphs of Gower Street. Dr. Otto Hahn, who is working at University College, has discovered a new radioactive element, extracted from a mineral from Ceylon, named Thorianite, and possibly, it is conjectured, the substance which renders thorium radioactive. Its activity is at least 250,000 times as great as that of thorium, weight for weight. It gives off a gas (generally called an emanation), identical with the radioactive.... Discover the Harriet Hahn popular books. Find the top 100 most popular Harriet Hahn books.