Hassium element chemistry

The chemistry of hassium has been studied recently using the formation of chemically stable, volatile HSO4, a property of Group 10 (VIII) elements. Thermo-chromatography has shown Hs04 to be less volatile than Os04, a result in agreement with some relativistic predictions but not others (Fig. 15.17). 

Kratz, J.V. Chemistry of Seaborgiuim and Prospects for Chemical Studies of Bohrium and Hassium , In Proceedings of The Robert A. Welch Foundation 41st Conference on Chemical Research, The Transactinide Elements , Houston, Texas, 27-28 October 1997, pp. 65. 

Yakushev, A.B., Vakatov, V.I., Vasko, V., Lebedev, V.Ya., Timokhin, S.N., Tsyganov, Yu.S., Zvara, I. "On-line Experiments with Short-lived Osmium Isotopes as a Test of the Chemical Identification of the Element 108 - Hassium" In Extended Abstracts of "1st International Conference on Chemistry and Physics of the Transactinide Elements", Seeheim, Germany, 26-30 September 1999, P-M-17. 

The chemistry of elements 104 through 106 has successfully been studied on this atom-at-a-time basis (see Refs. 11-14 for reviews). Recently, the chemistry of bohrimn (element 107) has been investigated for the first time by using an isothermal gas-phase system [15] and the first chemical studies of element 108 (hassium) have been reported [16]. Experiments with even heavier elements such as 112 [17] are imderway and others are planned as well. Complete overviews of the experimental procedures and results can be found in Ref. 46. 

For element 104 the names Kurchatovium (Ku) and Rutherfordium (Rf) were proposed by the groups at Dubna and Berkeley, respectively, thereby emphasizing their claim to the discoveries. The International Union on Pure and Applied Chemistry (lUPAC) has now decided on the following names element 104 Rutherfordium (Rf), element 105 Dubnium (Db), element 106 Seaborgium (Sg), element 107 Bohrium (Bh), element 108 Hassium (Hs), and element 109 Meitnerium (Mt). In the Periodic Table and nuclide charts we have thus used io4Rf. 106 8 107 > 108 So far no names have been... 

When a scientist discovered a new element in the early days of chemistiy, he or she had the honor of naming it. Now researchers must submit their choices for a name to an international committee called the International Union of Pure and Applied Chemistry before they can be placed on the periodic table. In 1997, the lUPAC decided on names for the elements from 104 through 111. These eight elements are now called rutherfordium (Rf), dubnium (Db), sea-borgium (Sg), bohrium (Bh), hassium... 

Abstract In this chapter, the chemical properties of the man-made transactinide elements rutherfordium, Rf (element 104), dubnium, Db (element 105), seaborgium, Sg (element 106), bohrium, Bh (element 107), hassium, Hs (element 108), and copernicium, Cn (element 112) are reviewed, and prospects for chemical characterizations of even heavier elements are discussed. The experimental methods to perform rapid chemical separations on the time scale of seconds are presented and comments are given on the special situation with the transactmides where chemistry has to be studied with single atoms. It follows a description of theoretical predictions and selected experimental results on the chemistry of elements 104 through 108, and element 112. 

Hassium (Z = 108) is the lightest superheavy element that has been produced directly in " Ca-induced reactions. The 20-s isotope °Hs has been produced in the Ra(" Ca,4n) reaction with a cross section of 8 pb [133]. Difficulties in target handling and a limited cross section favor the production of this isotope via the hot-fusion reaction " Cm( Mg,4n) for radiochemistry experiments [179, 180] (see Sect. 2.2 and Gas-Phase Chemistry of Superheavy Elements ). A single... 

It was emphasized in [1] that the nuclear decay properties of the isotope to be used in these studies must be well known and have unique decay characteristics suitable for detection and positive identification on an atom-at-a-time basis in order to verify that it is from the element whose chemistry is to be studied It must have a half-life comparable to the proposed chemical separation procedure as well as a reasonable production and detection rate to permit statistically significant results to be obtained, and must give the same results for a few atoms as for macro amounts. For the transactinide elements, production rates range from a few atoms per minute for rutherfordium (Rf, Z = 104) to only about one atom per day in the case of elements 108 (hassium, Hs), 112, and 114, the heaviest elements studied to date with chemical techniques. Details of these chemical investigations are outlined in Liquid-Phase Chemistry of Superheavy Elements and Gas-Phase Chemistry of SuperheavyElements . 

Abstract An overview over the chemical separation and characterization experiments of the four transactinide elements so far studied in liquid phases, rutherfordium (Rf), dubnium (Db), seaborgium (Sg), and hassium (Hs), is presented. Results are discussed in view of the position of these elements in the Periodic Table and of their relation to theoretical predictions. Short introductions on experimental techniques in liquid-phase chemistry, specifically automated rapid chemical separation systems, are also given. Studies of nuclear properties of transactinide nuclei by chemical isolation will be mentioned. Some perspectives for further liquid-phase chemistry on heavier elements are briefly discussed. 

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