Ida Noddack

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Ida Noddack : biography

25 February 1896 – 24 September 1978

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. By reanalysing the original experimental conditions, we conclude that the detection limit for their observing the X-rays of Z = 43 can be 1000 times lower than the 10−9 detection limit for the element Z = 75.

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!""I simulated the X-ray spectra that would be expected for Van Assche’s initial estimates of the Noddacks’ residue compositions. …Over the next couple of years, we refined our reconstruction of their analytical methods and performed more sophisticated simulations. The agreement between simulated and reported spectra improved further. "

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 99technetium content expected in a typical pitchblende (50% uranium) is about 10 −10 g/kg of ore. F. Habashi pointed out that uranium was never more than about 5% in Noddacks’ columbite samples, and the amount of element 43 could not exceed 3 × 10 −11 µg/kg of ore. Such a low quantity could not be weighed, nor give X-ray lines of element 43 clearly distinguishable from the background noise. The only way to detect its presence is to carry out radioactive measurements, a technique the Noddacks did not use, but Segrè and Perrier did.Abstract: A careful study of the history of the element 43 covering a period of 63 years since 1925 reveals that there is no reason for believing the Noddacks and Berg have discovered element 43. … P. H. Van Assche and J. T. Armstrong, cannot stand up to the well-documented assertion of the well-established physicist Paul K. Kuroda (1917 2001) in his paper, "A Note on the Discovery of Technetium" that the Noddacks did not discover technetium, then known as masurium. More about this matter can be found in Kuroda’s book, The Origin of Chemical Elements and the Oklo Phenomenon, and the book Ida Noddack (1896 1978). Personal Recollections on the Occasion of 80th Anniversary of the Discovery of Rhenium recently published by the writer…Fathi Habashi

  • Since the publication in this Journal of my paper on the discovery of element 43 (1), I have received a few letters questioning the correctness of the next to last paragraph, in the section entitled Nemesis….

I am deeply indebted to George B. Kauffman, Fathi Habashi, Gunter Herrmann, and Jean Pierre Adloff, who provided me with additional information and convinced me to better consider the published material on the so-called Noddacks’ rehabilitation and to correct with this letter my gross mistake, for which I apologize. Roberto Zingales

  1. Zingales, R. J. Chem. Educ. 2005, 82, 221227

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.Masataka Ogawa’s discovery of nipponium was accepted once in the periodic table of chemical elements as the element 43, but disappeared later. However, nipponium clearly shows characteristics of rhenium (Z=75) by inspection of his papers from the modern chemical viewpoints…a record of X-ray spectrum of Ogawa’s nipponium sample from thorianite was contained in a photographic plate reserved by his family. The spectrum was read and indicated the absence of the element 43 and the presence of the element 75In a recent evaluation of the discovery of "nipponium," supposed to be element 43 by Masataka Ogawa in 1908, and confirmed but not published by his son Eijiro in the 1940s, Kenji Yoshihara remeasured a photographic plate of an X-ray spectrum taken by Ogawa and found the spectral lines were those of rhenium. Thus actually, rhenium was discovered many years before Noddack, Tacke, and Berg’s work.Element 75 was isolated in 1908 by the Japanese chemist Masataka Ogawa and named nipponium. He inadequately assigned it as element 43 (technetium). From the modern chemical viewpoint it has to be considered to be element 75.