Nuclear Fission Lise Meitner, Otto Hahn, LeóSzilárd
Lise Meitner Biography • Lise Meitner was born on November 7, 1878, in Vienna, Austria. • She entered the University of Vienna in 1901, studying physics. • After she obtained her doctorate degree in 1906, she went to Berlin in 1907 to study with the chemist, Otto Hahn • She worked together with Hahn for 30 years, each of them leading a section in Berlin's Kaiser Wilhelm Institute for Chemistry. • In1966, she was awarded the Enrico Fermi Award • Meitner retired to Cambridge, England, in 1960, where she died October 27 • In 1992, element 109, the heaviest known element in the universe, was named Meitnerium (Mt) in her honor.
Important Works • Meitner studied physics and became the second woman to obtain a doctoral agree in physics at the University of Vienna in 1905 • In 1917, she and Hahn discovered the first long-lived isotope of the element protactinium, for which she was awarded the Leibniz Medal by the Berlin Academy of Sciences • In 1918, she helped to discover the element protactinium. • In 1922, she discovered the cause, known as the Auger effect, of the emission from surfaces of electrons with 'signature' energies • While studying the physical properties of radioactive substances, she also discovered that the neutron-bombarded uranium was causing the nucleus to split, naming this process nuclear fission. • In 1923, Meitner discovered the radiation-less transition known as the Auger effect, which is named for Pierre Victor Auger, a French scientist who discovered the effect two years later.
Lise Meitner and Nuclear Fission • Meitner and Frisch were the first to articulate a theory of how the nucleus of an atom could be split into smaller parts. They found that Uranium nuclei had split to form barium and krypton, accompanied by the ejection of several neutrons and a large amount of energy (the latter two products accounting for the loss in mass). • She had discovered the reason that no stable elements beyond uranium (in atomic number) existed naturally; the electrical repulsion of so many protons overcame the strong force • Meitner also first realized that Einstein's famous equation, E = mc2, explained the source of the tremendous releases of energy in nuclear fission, by the conversion of mass into energy. • Meitner recognized the possibility for a chain reaction of enormous explosive potential.
Otto Hahn Biography • Born March 8th 1879 in Frankfurt am Main, Germany • Died July 28 1968 • Awarded Nobel Peace prize for chemistry in 1944 • Doctorate degree from the University of Munich • 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. • Colleges: Lise Meitner, Fritz Strassmann and Leo Sziland • Was a soldier in World War I from 1914 to 1918
Important Works • Hahn discovered a new radioactive substance called radiothorium as he prepared radium salts • Hahn and Lise Meitner collaborated 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. • He also discovered mesothorium, protactinium, uranium Z • uranium Z was a very important discovery because it was the first case of a nuclear isomerism of radioactive atoms
Nuclear Fission Discovery • In 1934 Hahn’s attention was captured by Enrico Fermi’s work. • Fermi discovered that when uranium was bombarded with neutrons, radioactive products were formed. She concluded that these products were artificial elements that were similar to the uranium. • Hahn and Strassmann showed that the radioactive products were barium not uranium. This indicated that the uranium had split into two lighter atomswhich is know to be nuclear fission
Important to the Development of Chemistry • Dr. Hahn is know as the “the father of nuclear chemistry” • He helped invent the atomic bomb because of his discovery of nuclear fission • Nuclear fission in the atomic bomb - Nuclear fission 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 recognized the danger of the atomic bombs and advised us not to use them.
Leo Szilard Biography • Leo Szilard was born on February 11, 1898, in Budapest, Austria-Hungary (now Hungary). • Szilard was instrumental in getting the United States working on the atomic bomb. • He earned his Ph.D. in physics from the University of Berlin in 1922. • In 1927, Szilard became an instructor at the University of Berlin. • Szilard worked with Enrico Fermi to build the first nuclear reactor. • He started the Council for a Livable World in 1962, which is still dedicated to reducing the threat posed by nuclear weapons. • Leo Szilard died on May 30, 1964, in La Jolla, California.
Leo Szilard and Nuclear Fission • Found that it was possible to split the nucleus of a uranium atom by bombarding it with neutrons, the uncharged part of atoms. As the uranium nucleus split, some of its mass was converted to energy. • Leo Sziland worked on his thesis, which explored thermodynamics, or the study of the physics of heat. • Was the first person to conceive of the nuclear chain reaction and the atomic bomb. He was noted for his contributions to the fields of thermodynamics, biophysics, nuclear physics, and the development of atomic energy.
Leo Szilard Important Works • Szilard and another scientist Fermi found that uranium would work best to sustain a chain reaction is. In 1942 Szilard was responsible for the first ever human controlled chain reaction by having boron-free graphite produced. • Manhattan Project: the creation of the atomic bomb. • Szilard and Fermi created the first neutronic reactor and his greatest contribution was the controlled nuclear chain reaction that could be used as a power source for an atomic bomb. • Cobalt bomb: a nuclear weapon that he said could destroy all life on earth • Szilárd realized that if neutrons could initiate any sort of energy-producing nuclear reaction, and could be produced themselves by the same reaction, energy might be obtained with little input, since the reaction would be self-sustaining. • He filed for a patent on the concept of the neutron-induced nuclear chain reaction. Szilárd also was the co-holder of the patent on the nuclear reactor
Works Cited • http://www.chemheritage.org/discover/online-resources/chemistry-in-history/themes/atomic-and-nuclear-structure/hahn-meitner-strassman.aspx • http://shsphysics.wikispaces.com/Otto+Hahn • http://shsphysics.wikispaces.com/Leo+Szilard
More Works Cited • http://www.biography.com/people/leo-szilard-9500919?page=2 • http://www.ask.com/question/what-did-lise-meitner-invent • http://www.atomicarchive.com/Bios/Meitner.shtml • http://www.ask.com/wiki/Lise_Meitner • http://en.wikipedia.org/wiki/Leó_Szilárd#Developing_the_idea_of_the_nuclear_chain_reaction