Darmstadtium is a chemical element with the symbol "Ds" and atomic number 110. It is placed as the heaviest member of group 10, but no known isotope is sufficiently stable to allow chemical experiments to confirm its placing in that group. This synthetic element is one of the so-called super-heavy atoms and was first synthesized in 1994, at a facility near the city of Darmstadt, Germany, from which it takes its name. The longest-lived and heaviest isotope known is 281aDs with a half- life of ~10 s although a possible nuclear isomer, 281bDs has an unconfirmed half-life of about 4 minutes. Darmstadtium was first created on November 9, 1994, at the Gesellschaft für Schwerionenforschung (GSI) in Darmstadt, Germany, by Peter Armbruster and Gottfried Münzenberg, under the direction of professor Sigurd Hofmann. Four atoms of it were detected by a nuclear fusion reaction caused by bombarding a lead-208 target with nickel-62 ions: 208 82Pb + 62 28Ni → 269 110Ds + 1 0n Darmstadtium was first given the temporary name ununnilium (symbol: Uun). Once recognized as discoverers, the team at GSI considered the names darmstadtium (Ds) and wixhausium (Wi) for element 110. They decided on the former and named the element after the city near the place of its discovery, Darmstadt and not the suburb Wixhausen itself. The new name was officially recommended by IUPAC on August 16, 2003. The name was approved on November 4, 2011. High oxidation states are expected to become more stable as the group is descended, so darmstadtium is expected to form a stable hexafluoride, DsF6, in addition to DsF5 and DsF4. Halogenation should result in the formation of the tetrahalides, DsCl4, DsBr4, and DsI4. Like other Group 10 elements, darmstadtium can be expected to have notable hardness and catalytic properties. References: ^ Hofmann, S.; Ninov, V.; Heßberger, F. P.; Armbruster, P.; Folger, H.; Münzenberg, G.; Schött, H. J.; Popeko, A. G. et al. (1995). "Production and decay of 269110". Zeitschrift für Physik A 350 (4): 277. Bibcode 1995ZPhyA.350..277H. doi:10.1007/BF01291181. ^Hofmann, S (1998). "New elements - approaching". Reports on Progress in Physics 61 (6): 639. Bibcode 1998RPPh...61..639H. doi:10.1088/0034-4885/61/6/002 . ^ Karol, P. J.; Nakahara, H.; Petley, B. W.; Vogt, E. (2001). "On the discovery of the elements 110-112 (IUPAC Technical Report)". Pure and Applied Chemistry 73 (6): 959. doi:10.1351/pac200173060959. ^ "ununnilium - Definitions from Dictionary.com". Dictionary.reference.com. Retrieved 2011-11-05. ^ "Three new elements approved", Institute of Physics website, retrieved 4 Nov 2011 ^ Ginter, T. N.; Gregorich, K.; Loveland, W.; Lee, D.; Kirbach, U.; Sudowe, R.; Folden, C.; Patin, J. et al. (2003). "Confirmation of production of element 110 by the 208Pb(64Ni,n) reaction". Physical Review C 67 (6): 064609. Bibcode 2003PhRvC..67f4609G. doi:10.1103/PhysRevC.67.064609. ^ C. Samanta, P. Roy Chowdhury and D.N. Basu (2007). "Predictions of alpha decay half lives of heavy and superheavy elements". Nucl. Phys. A 789: 142–154. arXiv:nucl-th/0703086. Bibcode 2007NuPhA.789..142S. doi:10.1016/j.nuclphysa.2007.04.001. ^ P. Roy Chowdhury, C. Samanta, and D. N. Basu (2008). "Search for long lived heaviest nuclei beyond the valley of stability". Phys. Rev. C 77 (4): 044603. Bibcode 2008PhRvC..77d4603C. doi:10.1103/PhysRevC.77.044603. ^ P. Roy Chowdhury, C. Samanta, and D. N. Basu (2008). "Nuclear half-lives for α - radioactivity of elements with 100 ≤ Z ≤ 130". At. Data & Nucl. Data Tables 94 (6): 781. Bibcode 2008ADNDT..94..781C. doi:10.1016/j.adt.2008.01.003