Who created the element hassium?
13764#9
The name "hassium" was proposed by Peter Armbruster and his colleagues, the officially recognised German discoverers, in September 1992. It is derived from the Latin name "Hassia" for the German state of Hesse where the institute is located. In 1994, IUPAC Commission on Nomenclature of Inorganic Chemistry recommended that element 108 be named "hahnium" (Hn) after the German physicist Otto Hahn so that elements named after Hahn and Lise Meitner (meitnerium) would be next to each other, honoring their joint discovery of nuclear fission. This was because they felt that Hesse did not merit an element being named after it. GSI protested saying that this contradicted the long-standing convention to give the discoverer the right to suggest a name; the American Chemical Society supported the GSI. IUPAC relented and the name "hassium" (Hs) was adopted internationally in 1997.
Hassium
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Also in 1984, a research team led by Peter Armbruster and Gottfried Münzenberg at the Gesellschaft für Schwerionenforschung (GSI; "Institute for Heavy Ion Research") in Darmstadt, Hesse, West Germany, attempted to create element 108. The team bombarded a target of lead with accelerated nuclei of iron. They reported synthesis of 3 atoms of 108.
Hassium
13764#8
According to Mendeleev's nomenclature for unnamed and undiscovered elements, hassium should be known as "eka-osmium". In 1979, IUPAC published recommendations according to which the element was to be called "unniloctium" (with the corresponding symbol of "Uno"), a systematic element name as a placeholder, until the element was discovered (and the discovery then confirmed) and a permanent name was decided on. Although widely used in the chemical community on all levels, from chemistry classrooms to advanced textbooks, the recommendations were mostly ignored among scientists in the field, who either called it "element 108", with the symbol of "E108", "(108)", or even simply "108", or used the proposed name "hassium".
Hassium
2527236#0
Hassium (Hs) is a synthetic element, and thus a standard atomic weight cannot be given. Like all synthetic elements, it has no stable isotopes. The first isotope to be synthesized was Hs in 1984. There are 12 known isotopes from Hs to Hs and 1–4 isomers. The longest-lived isotope is Hs with a half-life of 10 seconds.Super-heavy elements such as hassium are produced by bombarding lighter elements in particle accelerators that induce fusion reactions. Whereas most of the isotopes of hassium can be synthesized directly this way, some heavier ones have only been observed as decay products of elements with higher atomic numbers.
Isotopes of hassium
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Hassium is the sixth member of the 6d series of transition metals and is expected to be much like the platinum group metals. Calculations on its ionization potentials, atomic radius, as well as radii, orbital energies, and ground levels of its ionized states are similar to that of osmium, implying that hassium's properties would resemble those of the other group 8 elements, iron, ruthenium, and osmium. Some of these properties were confirmed by gas-phase chemistry experiments. The group 8 elements portray a wide variety of oxidation states, but ruthenium and osmium readily portray their group oxidation state of +8 (the second-highest known oxidation state for any element, which is very rare for other elements) and this state becomes more stable as the group is descended. Thus hassium is expected to form a stable +8 state. Analogously to its lighter congeners, hassium is expected to also show other stable lower oxidation states, such as +6, +5, +4, +3, and +2. Indeed, hassium(IV) is expected to be more stable than hassium(VIII) in aqueous solution.
Hassium
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In the periodic table of the elements, it is a d-block transactinide element. Hassium is a member of the 7th period and belongs to the group 8 elements: it is thus the sixth member of the 6d series of transition metals. Chemistry experiments have confirmed that hassium behaves as the heavier homologue to osmium in group 8. The chemical properties of hassium are characterized only partly, but they compare well with the chemistry of the other group 8 elements. In bulk quantities, hassium is expected to be a silvery metal that reacts readily with oxygen in the air, forming a volatile tetroxide.
Hassium
2527236#2
Before the first successful synthesis of hassium in 1984 by the GSI team, scientists at the Joint Institute for Nuclear Research (JINR) in Dubna, Russia also tried to synthesize hassium by bombarding lead-208 with iron-58 in 1978. No hassium atoms were identified. They repeated the experiment in 1984 and were able to detect a spontaneous fission activity assigned to Sg, the daughter of Hs. Later that year, they tried the experiment again, and tried to chemically identify the decay products of hassium to provide support to their synthesis of element 108. They were able to detect several alpha decays of Es and Fm, decay products of Hs.
Isotopes of hassium
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Hassium has been observed as decay products of darmstadtium. Darmstadtium currently has eight known isotopes, all of which have been shown to undergo alpha decays to become hassium nuclei, with mass numbers between 263 and 277. Hassium isotopes with mass numbers 266, 273, 275, and 277 to date have only been produced by darmstadtium nuclei decay. Parent darmstadtium nuclei can be themselves decay products of copernicium, flerovium, or livermorium. To date, no other elements have been known to decay to hassium. For example, in 2004, the Dubna team identified hassium-277 as a final product in the decay of livermorium via an alpha decay sequence:
Isotopes of hassium
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The synthesis of element 108 was first attempted in 1978 by a research team led by Yuri Oganessian at the Joint Institute for Nuclear Research (JINR) in Dubna, Moscow Oblast, Russian SFSR, Soviet Union. The team used a reaction that would generate 108 from radium and calcium. The researchers were uncertain in interpreting result data; the paper did not unambiguously claim discovery. That same year, another team at JINR investigated the possibility of synthesis of element 108 in reactions between lead and iron; they were uncertain in interpreting result data as well, openly suggesting a possibility that element 108 had not been created.
Hassium
46825#69
Hahn's death did not stop his public acclamation. Proposals were made at different times, first in 1971 by American chemists, that the newly synthesized element no. 105 should be named hahnium in Hahn's honor; in 1997 the IUPAC (International Union of Pure and Applied Chemistry) named it dubnium, after the Russian research center in Dubna (see element naming controversy). Although element 108 was given the name hassium (after Hesse) by its officially recognized German discoverers in 1992, a 1994 IUPAC committee recommended that it be named hahnium (Hn), in spite of the long-standing convention to give the discoverer the right to suggest a name. This recommendation was not adopted, following protests from the German discoverers, and the name hassium (Hs) was adopted internationally in 1997.
Otto Hahn