Ida Noddack

Ida Tacke was born in Lackhausen (nowadays a part of the city of Wesel) in the northern Rhine region in 1896. She described how she picked her path of study by stating, "since I did not want to be a teacher at all, and research and industry employed proportionally fewer physicists at that time, I decided to become a chemist– a decision that was welcomed by my father who owned a small varnish factory in the Lower Rhine region." She chose to attend the Technische Hochschule Charlottenburg because she was drawn to its long and demanding programs. She entered the school in 1915, six years after women were allowed to study in all of Berlin's universities. Nine out of the eighty-five members of her class studied chemistry. In 1918, she graduated from the university with a degree in chemical and metallurgical engineering, specifically on higher aliphatic fatty acid anhydrides. She was one of the first women in Germany to study chemistry, and she was a part of one of the first generations of female students in Germany. In addition, the percent of women studying chemistry increased from 3% before World War I to 35% during the war. Both before and after their marriage they worked as partners, an "Arbeitsgemeinschaft" or "work unit." ==Nuclear fission==

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 published a paper questioning Fermi’s conclusion. Noddack correctly criticized Enrico Fermi's 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, Noddack's paper "On Element 93" suggested a number of possibilities, but centered on Fermi's 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 Fermi's 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, as Noddack's theory did not exhibit experimental proof or a theoretical basis, the paper was generally ignored and mocked. Several German scientists, like Otto Hahn, saw Noddack's work as "ridiculous." ==Element discovery==

Noddack and her husband-to-be looked for the then still unknown elements 43 and 75 at the Physikalisch-Technische Reichsanstalt. In 1925, they published a paper (Zwei neue Elemente der Mangangruppe, Chemischer Teil) and called the new elements rhenium (75) and masurium (43). They named the elements rhenium in respect of Ida's birthplace, and masurium in honor of his. Based on this discovery, Belgian physicist Pieter van Assche constructed an analysis of their data to show that the detection limit of Noddacks' analytical method could have been 1000 times lower than the 10−9 value reported in their paper, in order to show the Noddacks could have been the first to find measurable amounts of element 43, as the ores they had analyzed contained uranium. Using Van Assche's estimates of the Noddacks' residue compositions, NIST scientist John T. Armstrong, simulated the original X-ray spectrum with a computer, and claimed that the results were "surprisingly close to their published spectrum!" Gunter Herrmann from the University of Mainz examined van Assche's arguments, and concluded they were developed ad hoc, and forced to a predetermined result. According to Kenna and Kuroda content expected in a typical pitchblende (50% uranium) is about of ore. Following on the van Assche and Armstrong claims, an investigation was made into the works of Masataka Ogawa who had made a prior claim to the Noddacks. In 1908 he claimed to have isolated element 43, calling it Nipponium. Using an original plate (not a simulation), Kenji Yoshihara determined Ogawa had not found the Period 5 Group 7 element 43 (eka-manganese), but had successfully separated Period 6 Group 7 element 75 (dvi-manganese) (rhenium), preceding the Noddacks by 17 years. However this claim has been disputed by chemistry historian Eric Scerri in his book titled "A Tale of Seven Elements". ==Notable nominations and awards==

Ida Noddack was nominated three times for the Nobel Prize in Chemistry due to her discovery of rhenium and masurium. Noddack and her husband were repeatedly nominated for the Nobel Prize in 1932, 1933, 1935 and 1937 (once by Walther Nernst and K. L. Wagner for 1933; both Noddacks were nominated by W. J. Müller for 1935 and by A. Skrabal for 1937). In 2020 a memorial medal of the discovery was issued by ISTR, designed by Igor Petrov. ==Bibliography==