Hassium Facts - Hs or Element 108

Element atomic number 108 is hassium, which has the element symbol Hs. Hassium is one of the manmade or synthetic radioactive elements. Only about 100 atoms of this element have been produced so there is not a lot of experimental data for it. Properties are predicted based on the behavior of other elements in the same element group. Hassium is expected to be a metallic silver or gray metal at room temperature, much like the element osmium.

Here are interesting facts about this rare metal:

Discovery: Peter Armbruster, Gottfried Munzenber and co-workers produced hassium at GSI in Darmstadt, Germany in 1984. The GSI team bombarded a lead-208 target with iron-58 nuclei. However, Russian scientists had attempted to synthesize hassium in 1978 at the Joint Institute for Nuclear Research in Dubna. Their initial data was inconclusive, so they repeated the experiments five years later, producing Hs-270, Hs-264, and Hs-263.

Element Name: Before its official discovery, hassium was referred to as "element 108", "eka-osmium" or "unniloctium". Hassium was the subject of a naming controversy over which team should be given official credit for discovering element 108. The 1992 IUPAC/IUPAP Transfermium Working Group (TWG) recognized the GSI team, stating that their work was more detailed. Peter Armbruster and his colleagues proposed the name hassium from the Latin Hassias meaning Hess or Hesse, the German state, where this element was first produced. In 1994, an IUPAC committee recommended making the element's name hahnium (Hn) in honor of the German physicist Otto Hahn. This was despite the convention of allowing the discovering team the right to suggest a name. The German discoverers and the American Chemical Society (ACS) protested the name change and the IUPAC finally allowed element 108 to be officially named hassium (Hs) in 1997.

Atomic Number: 108

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Chemical & Physical Properties of the Element Hafnium

By Anne Marie Helmenstine, Ph.D.

Symbol: Hs

Atomic Weight: [269]

Group: Group 8, d-block element, transition metal

Electron Configuration: [Rn] 7s² 5f¹⁴ 6d⁶

Appearance: Hassium is believed to be a dense solid metal at room temperature and pressure. If enough of the element were produced, it is expected it would have a shiny, metallic appearance. It's possible hassium could be even more dense than the heaviest known element, osmium. The predicted density of hassium is 41 g/cm³.

Properties: It's likely hassium reacts with oxygen in air to form a volatile tetraoxide. Following periodic law, hassium should be the heaviest element in group 8 of the periodic table. It is predicted that hassium has a high melting point, crystallizes in the hexagonal close-packed structure (hcp), and has a bulk modulus (resistance to compression) on par with diamond (442 GPa). Differences between hassium and its homologue osmium would likely be due to relativistic effects.

Sources: Hassium was first synthesized by bombarding lead-208 with iron-58 nuclei. Only 3 atoms of hassium were produced at this time. In 1968, Russian scientist Victor Cherdyntsev claimed to have discovered naturally-occurring hassium in a sample of molybdenite, but this was not verified. To date, hassium has not been found in nature. The short half-lives of the known isotopes of hassium mean no primordial hassium could have survived to the present day. However, it's still possible nuclear isomers or isotopes with longer half-lives might be found in trace quantities.

Element Classification: Hassium is a transition metal that is expected to have properties similar to those of the platinum group of transition metals. Like the other elements in this group, hassium is expected to have oxidation states of 8, 6, 5, 4, 3, 2. The +8, +6, +4, and +2 states will likely be the most stable, based on the element's electron configuration.

Isotopes: 12 isotopes of hassium are known, from masses 263 to 277. All of them are radioactive. The most stable isotope is Hs-269, which has a half-life of 9.7 seconds. Hs-270 is of particular interest because it possesses "magic number" of nuclear stability. The atomic number 108 is a proton magic number for deformed (nonspherical) nuclei, while 162 is a neutron magic number for deformed nuclei. This doubly magic nucleus has a low decay energy compared with other hassium isotopes. More research is needed to determine whether or not Hs-270 is an isotope in the proposed island of stability.

Health Effects: While the platinum group metals tend not to be particularly toxic, hassium presents a health risk because of its significant radioactivity.

Uses: At present, hassium is only used for research.

Sources

• Emsley, John (2011). Nature's Building Blocks: An A-Z Guide to the Elements (New ed.). New York, NY: Oxford University Press. p. 215–7. ISBN 978-0-19-960563-7.
• Hoffman, Darleane C.; Lee, Diana M.; Pershina, Valeria (2006). "Transactinides and the future elements". In Morss; Edelstein, Norman M.; Fuger, Jean. The Chemistry of the Actinide and Transactinide Elements (3rd ed.). Dordrecht, The Netherlands: Springer Science+Business Media. ISBN 1-4020-3555-1.
• "Names and symbols of transfermium elements (IUPAC Recommendations 1994)". Pure and Applied Chemistry 66 (12): 2419. 1994.
• Münzenberg, G.; Armbruster, P.; Folger, H.; et al. (1984). "The identification of element 108" (PDF). Zeitschrift für Physik A. 317 (2): 235–236. doi:10.1007/BF01421260
• Oganessian, Yu. Ts.; Ter-Akopian, G. M.; Pleve, A. A.; et al. (1978). Опыты по синтезу 108 элемента в реакции [Experiments on the synthesis of element 108 in the ²²⁶Ra+⁴⁸Ca reaction] (in Russian). Joint Institute for Nuclear Research.