Noddack

L. Rhenus, Rhine) Discovery of rhenium is generally attributed to Noddack, Tacke, and Berg, who announced in 1925 they had detected the element in platinum ore and columbite. They also found the element in gadolinite and molybdenite. By working up 660 kg of molybdenite in 1928 they were able to extract 1 g of rhenium. 

The isolation and identification of 4 radioactive elements in minute amounts took place at the turn of the century, and in each case the insight provided by the periodic classification into the predicted chemical properties of these elements proved invaluable. Marie Curie identified polonium in 1898 and, later in the same year working with Pierre Curie, isolated radium. Actinium followed in 1899 (A. Debierne) and the heaviest noble gas, radon, in 1900 (F. E. Dorn). Details will be found in later chapters which also recount the discoveries made in the present century of protactinium (O. Hahn and Lise Meitner, 1917), hafnium (D. Coster and G. von Hevesey, 1923), rhenium (W. Noddack, Ida Tacke and O. Berg, 1925), technetium (C. Perrier and E. Segre, 1937), francium (Marguerite Percy, 1939) and promethium (J. A. Marinsky, L. E. Glendenin and C. D. Coryell, 1945). 

The Noddacks also claimed to have detected element 43 and named it masurium after Masuren in Prussia. This claim proved to be incorrect, however, and the element was actually detected in 1937 in Italy by C. Perrier and E. Segre in a sample of molybdenum which had been bombarded with deuterons in the cyclotron of E. O. Lawrence in California. It was present in the form of the emitters Tc and Tc... 

This kind of argument was given by Ida Noddack, for example, as described by Van Tiggelen [16]. 

Rhenium (75) was discovered in 1925 by Ida Tacke and Walter Noddack as the last naturally occurring element. The first artificially produced element was identified by Emilio G. Segre in 1937. Ernest Lawrence detected technetium in a molybdenum sample, which he had bombarded in his cyclotron. All elements discovered since then have been generated artificially. 

The discovery of the elements 43 and 75 was reported by Noddack et al. in 1925, just seventy years ago. Although the presence of the element 75, rhenium, was confirmed later, the element 43, masurium, as they named it, could not be extracted from naturally occurring minerals. However, in the cyclotron-irradiated molybdenum deflector, Perrier and Segre found radioactivity ascribed to the element 43. This discovery in 1937 was established firmly on the basis of its chemical properties which were expected from the position between manganese and rhenium in the periodic table. However, ten years later in 1937, the new element was named technetium as the first artificially made element. 

There had been some confusion about the discovery of element number 43 until in 1937 Perrier and Segre succeeded in producing it by deuteron irradiation of molybdenum placed in a cyclotron. A Japanese chemist by the name of Ogawa believed that he had succeeded in discovering this element in 1908, but in vain. Afterwards, in 1925 the Noddack group claimed to have discovered this element, but their claim turned out to be false. 

The development of chemistry itself has progressed significantly by analytical findings over several centuries. Fundamental knowledge of general chemistry is based on analytical studies, the laws of simple and multiple proportions as well as the law of mass action. Most of the chemical elements have been discovered by the application of analytical chemistry, at first by means of chemical methods, but in the last 150 years mainly by physical methods. Especially spectacular were the spectroscopic discoveries of rubidium and caesium by Bunsen and Kirchhoff, indium by Reich and Richter, helium by Janssen, Lockyer, and Frankland, and rhenium by Noddack and Tacke. Also, nuclear fission became evident as Hahn and Strassmann carefully analyzed the products of neutron-bombarded uranium. 

Rhenium (Re, [Xe]4/145river Rhine. Discovered (1925) by the German chemists W. Noddack, I. Noddack-Tacke and O.C. Berg in minute amounts in a sample of gadolinite (a basic silicate of Be, Fe and lanthanides). Silvery-white metal. 

Noddack und Mitarbeiter (Noddack, Eckert und Meier 1952 Noddack und Eckert 1953, Meier 1954) priiften das Vorhandensein... 

Auf Grund ihrer Ergebnisse halten Noddack und Mitarbeiter fur wahrscheinlich, daB auch beim photographischen ProzeB in den Sensi-bilisierungsfarbstoffen Elektronen frei werden und dann auf Bromsilber iibertreten. 

Noddack, W., G. Eckert u. H. Meier t)ber den Mechanismus der photographi-schen Sensibilisierung. Z. Elektrochem., Ber. Bunsenges. physik. Chem. 56, 735 (1952). 

Rhenium - the atomic number is 75 and the chemical symbol is Re. The name derives from the Latin rhenus for the Rhine river in Germany . It was discovered by x-ray spectroscopy in 1925 by the German chemists, Walter Noddack, Ida Tacke and Otto Berg. 

Until technetium was produced by nuclear reactions there had been numerous efforts to demonstrate the occurrence of the lacking element in the nature. In this context, the works of Noddack and Tacke as well as Berg and Tacke should be... 

Rhenium Re 1925 (Berlin, Germany) Walter Noddack, Ida Tacke Noddack and Otto Berg (all German) 155... 

Technetium Tc 1925 (Berlin, Germany) 1937 (Berkeley, California) Walter Noddack and Ida Tacke Noddack (both German) Emilio Segre (Italian-American) and Carlo Perrier (Italian) 130... 

Rhenium was the last naturally occurring chemical element to be discovered in 1925 by Noddack, Tacke, and Berg in the mineral gadolinite. The name of this extremely rare element (the estimated occurrence in the earth s crust is about 0.7 ppb ) is derived from the Rhine river. Residues from the processing of molybdenum ores represent the main source of the metal. 

The element was discovered in 1925 by Walter Noddack, Ida Tacke Noddack, and 0. Berg. They detected it by x-ray examination of platinum ores. X-ray studies also showed its occurrence in columbite and other minerals. It was named after the German river Rhine, called Rhenus in Latin. In 1929, Walter and Ida Noddack produced Ig of rhenium metal from 660 kg of Norwegian molybdenite. 

Existence of technetium was predicted from the vacant position in the Periodic Table between manganese and rhenium. Noddack, Tacke, and Berg reported its discovery in 1925 and named it masurium. The metal actually was never isolated from any source by these workers. Its existence, therefore, could not be confirmed. Perrier and Segre in 1937 produced this element by bombarding molybdenum metal with deuterons in a cyclotron. They named the element technetium derived from the Greek word technetos, meaning artificial. 

When H. G. ]. Moseley discovered the simple relationship which exists between the X-ray spectrum of an element and its atomic number, there were seven unfilled spaces in the periodic table. Elements 43, 61, 72, 75, 85, 87, and 91, were yet to be revealed. Element 91 (protactinium) was discussed with the radioactive elements in Chapter 29. In 1923 D. Coster and G. von Hevesy showed that element 72, hafnium, is widely distributed but that it had escaped detection because of its close resemblance to zirconium. Element 75 (rhenium) was announced by W. and l. Noddack in 1925, and is now a commercial article. 

Two new elements of the manganese group, numbers 43 (eka-manganese) and 75 (dwi-manganese), were announced in June, 1925, by the German chemists Dr. Walter Noddack and Dr. Ida Tacke of the Physico-Technical Testing Office in Berlin and Dr. Otto Berg of the Werner-Siemens Laboratory. The discovery was not accidental, but the... 

Noddack, Tacke, and Berg discover rhenium (element 75). 

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