Hassium Hs, element

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. 

At this time, to name an element a researcher or team of researchers must be certified by lUPAC as the discoverers of that element, at which time they are free to name the compound. The elements 104-109 were subject to a naming controversy. The originally proposed names of these elements by lUPAC were, in order, dub-nium, joliotium, rutherfordium, bohrium, hahnium, and meiterium. The names which appear on the current periodic table are, in order, rutherfordium (Rf), dubnium (Db), seaborgium, bohrium (Bh), hassium (Hs), and meitnerium (Mt). 

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... 

Element 108 was synthesized by the Darmstadt team in 1984 by bombarding ° Pb with Fe ions to create an element of mass 265. The element was later named hassium (Hs) after the state of Hessen, which includes the city of Darmstadt. The most stable isotope of hassium is °Hs, ty, 21 seconds. Extremely skilled online chemical investigations of this short-lived, ultrarare substance demonstrated the formation and some properties of HSO4, bearing similarity to its Group 8 relative OSO4. 

Hassium (Hs), Z = 108 was discovered in the reaction Pb( Fe, n) Hs (Miinzenberg et al. 1984b, 1987) and unambiguously confirmed in a later experiment (Hofmann et al. 1995a). This element was synthesized after meitnerium as theoretical predictions available at that time suggested the predominance of spontaneous fission with half-lives below microseconds for the doubly even hassium isotopes (Randrup et al. 1976). Hence, to proceed with the synthesis of meitnerium was considered to be safer since it was possible to profit twice fi-om the fission hindrance provided by the odd proton and the odd neutron, if an odd-odd nuclide was to be produced. The resulting observation of a decay is necessary for the identification of the new element with the correlation method. The synthesis of hassium with the unexpected... 

Element 108 Hassium (Hs) named after Hessen, Latin Hassia, its state of discovery (GSi Darmstadt with contribution from Dubna). 

Transactinide elements Artificial elements beyond the actinide elements, beginning with ratherfordium (Rf), element 104. The heaviest elements, synthesized until now, are the elements 114, 116, and 118. At present, bohrium (Bh), element 107, is the heaviest element which has been characterized chemically chemical studies of element 108, hassium (Hs), and element 112 are in preparation. 

In 1984 P. Armbruster s group at the Institute for Heavy Ion Research at Darmstadt bombarded lead-208 atoms with ions of iron-58. In 10 days of bombardment, they successfully produced three atoms of an isotope of element 108 with mass number 265. They suggested that the new element should be named hassium, which is derived from the Latin name Hassias for the German state of Hessen, in which the institute is situated. The name hassium Hs was adopted internationally in 1997. 

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. 

Hassium - the atomic number is 108 and the chemical symbol is Hs. The name derives from the Latin Hassia for the German state of Hesse , whose former capital was Darmstadt. The element was first synthesized by German physicists at the GSI (Center for Heavy-Ion Research) Lab at Darmstadt, Germany in 1984 using the nuclear reaction ° Pb ( Fe, n) Hs. The longest half-life associated with this unstable element is 11 minute Hs. 

Most of the chemical and physical properties of imniloctium (hassium) are unknown. What is known is that its most stable isotope (hassium-108) has the atomic weight (mass) of about 277. Hs-277 has a half-life of about 12 minutes, after which it decays into the isotope seaborgium-273 through either alpha decay or spontaneous fission. Hassium is the last element located at the bottom of group 8, and like element 107, it is produced by a cold fusion process that in hassium s case is accomplished by slamming iron (Fe-58) into particles of the isotope of lead (Pb-209), along with several neutrons, as follows ... 

CAS 54037-57-9[. Hassium is a chemical clement in the periodic table that has the symbol Hs and atomic number 108. It is a synthetic element whose most stable isotope is Hs-265. with a half-life of 2 ms. It was first synthesized in 1984 by a German research team led by Peter Armbruster and Gottfried MUnzenbcrg at Ihe Institute for Heavy Ion Research at Darmstadt The name hassium was proposed by them, derived from the... 

Hassium — (named for the German state, Hesse) Hs at. wt. [277] at. no. 108. This element was first synthesized and identified in 1964 by the same G.S.I. Darmstadt Group who first identified Bohrium and Meitnerium. Presumably this element has chemical properties similar to osmium. Isotope 108 was produced using a beam of Fe projectiles, produced by the Universal Linear Accelerator (UNILAC) to bombard a Pb target. Discovery oiBohrium Bind Meitnerium was made using detection of isotopes with odd proton and neutron numbers. 

Hassium, element 108, does not exist in nature but must be made in a particle accelerator. It was first created in 1984 and can be made by shooting mag-nesium-26 (ifMg) atoms at curium-248 ( HCm) atoms. The collisions between these atoms produce some hassium-265 (io Hs) atoms. The position of hassium in the periodic table (see Fig. 2.20) in the vertical column containing iron, ruthenium, and osmium suggests that hassium should have chemical properties similar to these metals. However, it is not easy to test this prediction—only a few atoms of hassium can be made at a given time and they last for only about 9 seconds. Imagine having to get your next lab experiment done in 9 seconds ... 

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