text: In 1934, Enrico Fermi bombarded uranium with neutrons in his laboratory in Rome, and identified a new type of radioactivity whose atomic chemistry differed greatly from uranium and similar elements. He published his findings claiming this to be evidence of a new transuranic element. Ida Noddack quickly published a paper questioning Fermi’s conclusion.  Noddack correctly criticized Enrico Fermis chemical proofs in his 1934 neutron bombardment experiments, from which he postulated that transuranic elements might have been produced. This theory was widely accepted for a few years. However, Noddacks paper "On Element 93" suggested a number of possibilities, but centered on Fermis failure to chemically eliminate all lighter than uranium elements in his proofs, rather than only down to lead. The paper is considered historically significant today not simply because she correctly pointed out the flaw in Fermis chemical proof but because she suggested the possibility that "it is conceivable that the nucleus breaks up into several large fragments, which would of course be isotopes of known elements but would not be neighbors of the irradiated element." In doing so she presaged what would become known a few years later as nuclear fission. However, Noddacks theory did not exhibit experimental proof or a theoretical basis for this possibility. Therefore, the paper was generally ignored and mocked by others, despite the fact that she was correct. Several German scientists, like Otto Hahn, saw Noddacks work as "ridiculous." A woman's position in the workplace had been dwindling for years due to the 1929 Wall Street crash. In 1932, a German law, replicating others in Europe, was put into place that obligated married women to leave their jobs and become housewives so that there would be more positions available for men. Noddack was able to escape this law due to her status as an "unpaid collaborator." This may have caused her to be looked down upon by men in the field as she was only able to work due to this loophole.
  Noddacks idea of nuclear fission was not confirmed until much later. Experiments along a similar line to Fermis, by Irène Joliot-Curie, Frédéric Joliot-Curie and Pavle Savić in 1938 raised what they called "interpretational difficulties" when the supposed transuranics exhibited the properties of rare earths rather than those of adjacent elements.  Ultimately on December 17, 1938, Otto Hahn and Fritz Strassmann provided chemical proof that the previously presumed transuranic elements were isotopes of barium, and Hahn wrote these exciting results to his exiled colleague Lise Meitner, explaining the process as a bursting of the uranium nucleus into lighter elements. Meitner and Otto Frisch utilized Fritz Kalckar and Niels Bohrs liquid drop hypothesis (first proposed by George Gamow in 1935) to provide a first theoretical model and mathematical proof of what Frisch coined nuclear fission. Frisch also experimentally verified the fission reaction by means of a cloud chamber, confirming the energy release. Therefore, Noddacks original hypothesis was finally accepted.