Otto Hahn


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http://nobelprize.org/nobel_prizes/chemistry/laureates/1944/hahn-bio.html

Biography
Otto Hahn was born in Frankfurt am Main, Germany on March 8, 1879. He was interested in chemistry when he was a teenager, and he conducted experiments at home. He studied chemistry at the University of Marburg and Munich. In 1901, he received his doctorate degree from the University of Munich with a thesis on organic chemistry. Hahn worked in various places gaining experience as a chemist from 1904 to 1906. For instance, he worked at the Chemical Institute at Marburg, University College in London, Physical Institute of McGill University in Montreal, and the Chemical Institute of the University of Berlin. Otto Hahn became a scientific member of the Kaiser Wilhelm Institute for Chemistry in 1912 and was Director from 1928 to 1945. In 1913, Hahn married Edith Junghans and the couple had one son named Hanno who died in 1960. Between 1914 and 1918, Otto Hahn participated in World War I. After serving in the military, he resumed his research in chemistry. Hahn put a lot of work into his research and he was rewarded with many discoveries in chemistry and various recognitions. Otto Hahn became a scientific member of the Kaiser Wilhelm Institute for Chemistry in 1912 and was Director from 1928 to 1945. In 1933, he was appointed Visiting Professor at Cornell University in New York. In 1944, he was awarded the Nobel Prize in Chemistry for the discovery of nuclear fission. He has served as President of the Max Planck Society in Western Germany was created Honorary President this Society in 1960. Hahn died on July 28, 1968 at age 89.
Scientific Research
Otto Hahn made many contributions to chemistry and his greatest contributions were in the field of radioactivity. He was not the only one working on these projects. He collaborated with many other scientists and they share the credit in the significant discoveries made in the field of chemistry. Working at the Chemical Institute at Marburg, Hahn made the discovery of a new radioactive substance called radiothorium as he prepared radium salts.The year 1907 marked the beginning of 30 years of collaboration between Hahn and Lise Meitner. They investigated beta rays and the use of the radioactive recoil to obtain new radioactive transformation products. They researched the absorbability and magnetic spectra of beta rays. In 1907, Hahn discovered mesothorium. Otto Hahn discovered protactinium which is a long-lived mother substance of the actinium series.Hahn also discovered uranium Z and this was important because it was the first case of a nuclear isomerism of radioactive atoms. Hahn and Meitner worked together on the discovery of the artificially active uranium isotope. This uranium isotope is the basic substance of the elements neptunium and plutonium. All of these discoveries were the result of hard work, but these discoveries also represent meaningful rewards for Hahn and the other scientists for their scientific research.

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Hahn and Meitner in 1913 http://en.wikipedia.org/wiki/Otto_Hahn

Discovery of Nuclear Fission
Otto Hahn’s work played an important role in the creation of the atomic bomb. He was actually known as “the father of nuclear chemistry” and as the “founder of the atomic age.” What connects Hahn to the atomic bomb is his most spectacular and recognized discovery that he made in 1938. Working with Dr. Strassmann, Hahn discovered the fission of uranium. This led him to win in 1944 the prestigious Nobel Prize in Chemistry. This discovery led directly to the development of the atomic bomb.
The path to discover nuclear fission began when, in 1934, Hahn’s attention was captured by Enrico Fermi’s work. Fermi found out that when uranium was bombarded with neutrons, radioactive products were formed. Fermi concluded that these products were artificial elements that were similar to the uranium. Hahn and Strassmann gathered evidence disproved Fermi’s conclusion. They showed that the radioactive products were barium not uranium. This indicated that the uranium had split into two lighter atoms. This process came to be called nuclear fission.
Nuclear fission is an exothermic reaction. It releases large amounts of energy in the form of electromagnetic radiation and kinetic energy. This energy can be used to drive the explosion of atomic bombs. A chain reaction occurs in a very fast and uncontrolled rate in nuclear weapons. An atomic bomb is a fission reactor that releases as much energy as possible and as rapidly as possible, before the reactor explodes. Hahn saw how dangerous and destructive atomic bombs were and he became a campaigner against the use of nuclear energy to make weapons. Because of his work, Otto Hahn became an influential and respected scientist whose legacy is still recognized today.
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Experimental apparatus used to discover nuclear fission in 1938http://en.wikipedia.org/wiki/Nuclear_fission#Fission_bombs
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