Technetium naming

Gr. technetos, artificial) Element 43 was predicted on the basis of the periodic table, and was erroneously reported as having been discovered in 1925, at which time it was named masurium. The element was actually discovered by Perrier and Segre in Italy in 1937. It was found in a sample of molybdenum, which was bombarded by deuterons in the Berkeley cyclotron, and which E. Eawrence sent to these investigators. Technetium was the first element to be produced artificially. Since its discovery, searches for the element in terrestrial material have been made. Finally in 1962, technetium-99 was isolated and identified in African pitchblende (a uranium rich ore) in extremely minute quantities as a spontaneous fission product of uranium-238 by B.T. Kenna and P.K. Kuroda. If it does exist, the concentration must be very small. Technetium has been found in the spectrum of S-, M-, and N-type stars, and its presence in stellar matter is leading to new theories of the production of heavy elements in the stars. 

Plutonium was the first element to be synthesized in weighable amounts (6,7). Technetium, discovered in 1937, was not isolated until 1946 and not named until 1947 (8). Since the discovery of plutonium in 1940, production has increased from submicrogram to metric ton quantities. Because of its great importance, more is known about plutonium and its chemistry than is known about many of the more common elements. The metallurgy and chemistry are complex. MetaUic plutonium exhibits seven aUotropic modifications. Five different oxidation states are known to exist in compounds and in solution. 

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. 

Technetium (Tc, [Kr]4 /65.vl), name and symbol after the Greek Tsxrmos (tech-nikos, artificial). Detected in Italy (1937) by Carlo Perrier and Emilio Segre in a sample of Mo which had been irradiated with deuterons at the E.O. Lawrence cyclotron in California. It was the first artificially produced element. 

Perrier and Segre suggested the name technetium , since it was the first element to be prepared artificially. 20 isotopes and numerous isomers with half-lives between about one second and several million years have hitherto been known (Table 1). 

A more efficient method of paper chromatography was developed by Beckman and Lederer making use of the formation of a technetiiun complex with thiourea in nitric acid. TcO is reduced by this reagent, in contrast to ReO". The paper is eluted with 2 N HCl. The R, values of technetium and rhenium have been found to be very different, namely 0.2 and 0.7, respectively. 

ORIGIN OF NAME Technetium s name was derived from the Greek word technetos, meaning "artificial."... 

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. 

In 1947 F. A. Paneth (10) pointed out that there was no justification in considering artificially prepared elements as different from those which occurred naturally. He therefore laid down the rule that the discoverers of such elements had the same right to name them as did the discoverers of any element. Perrier and Segre at once proposed the name technetium,... 

The first element ever to be produced artificially is that of atomic number 43. In 1937, Perrier and Segre isolated minute amounts of a radioactive isotope of this element from a sample of molybdenum that had been bombarded with deuterons in a cyclotron. This element was given the name technetium (Tc), which is derived from the Greek word meaning artificial. The bulk of the evidence now available indicates that this element does not occur in nature. Although several isotopes of... 

It is only in recent times that a polemic arose about the naming of element 43. See P. H. M. Van Assche, The ignored discovery of element Z=43, Nuclear Physics A480 (1988) 205-214 and G. Herrmann, Technetium or masurium - a comment on the history of element 43, Nuclear Physics A505 (1989) 352-360. 

Technetium. No stable isotopes of element 43 exist. Minute amounts of radioactive isotopes have been made, by Segre and his collaborators, who have named the element technetium, symbol Tc. 

All 37 isotopes of technetium are radioactive. The most stable of these isotopes, technetium-97 and technetium-98, have half lives of 2.6 million years and 4.2 million years, respectively. Isotopes are two or more forms of an element. Isotopes differ from each other according to their mass number. The number written to the right of the element s name is the mass number. The mass number represents the number of protons plus neutrons in the nucleus of an atom of the element. The number of protons determines the element, but the number of neutrons in the atom of any one element can vary. Each variation is an isotope. 

Nofetumomab merpentan possesses a linker and a chelsior that binds the technetium to the peptide. This is a phcnihloax ligand. 2.3.5.6-tetrafluorophenyl-4,S-bis-5- l-ethuxyclhyl -thioacctoamidopentanoatc. hence the name merpentan. 

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