Hassium

Hassium, 108Hs
Hassium
Pronunciation/ˈhæsiəm/ [1] (HASS-ee-əm)
Mass number[269] (data not decisive)[a]
Hassium in the periodic table
Hydrogen Helium
Lithium Beryllium Boron Carbon Nitrogen Oxygen Fluorine Neon
Sodium Magnesium Aluminium Silicon Phosphorus Sulfur Chlorine Argon
Potassium Calcium Scandium Titanium Vanadium Chromium Manganese Iron Cobalt Nickel Copper Zinc Gallium Germanium Arsenic Selenium Bromine Krypton
Rubidium Strontium Yttrium Zirconium Niobium Molybdenum Technetium Ruthenium Rhodium Palladium Silver Cadmium Indium Tin Antimony Tellurium Iodine Xenon
Caesium Barium Lanthanum Cerium Praseodymium Neodymium Promethium Samarium Europium Gadolinium Terbium Dysprosium Holmium Erbium Thulium Ytterbium Lutetium Hafnium Tantalum Tungsten Rhenium Osmium Iridium Platinum Gold Mercury (element) Thallium Lead Bismuth Polonium Astatine Radon
Francium Radium Actinium Thorium Protactinium Uranium Neptunium Plutonium Americium Curium Berkelium Californium Einsteinium Fermium Mendelevium Nobelium Lawrencium Rutherfordium Dubnium Seaborgium Bohrium Hassium Meitnerium Darmstadtium Roentgenium Copernicium Nihonium Flerovium Moscovium Livermorium Tennessine Oganesson
Os

Hs

(Uhb)
bohriumhassiummeitnerium
Atomic number (Z)108
Groupgroup 8
Periodperiod 7
Block  d-block
Electron configuration[Rn] 5f14 6d6 7s2[4]
Electrons per shell2, 8, 18, 32, 32, 14, 2
Physical properties
Phase at STPsolid (predicted)[5]
Density (near r.t.)27–29 g/cm3 (predicted)[6][7]
Atomic properties
Oxidation states(+2), (+3), (+4), (+6), +8[8][9][10] (brackets: prediction)
Ionization energies
  • 1st: 730 kJ/mol
  • 2nd: 1760 kJ/mol
  • 3rd: 2830 kJ/mol
  • (more) (predicted)[11]
Atomic radiusempirical: 126 pm (estimated)[12]
Covalent radius134 pm (estimated)[13]
Other properties
Natural occurrencesynthetic
Crystal structurehexagonal close-packed (hcp)
Hexagonal close-packed crystal structure for hassium

(predicted)[5]
CAS Number54037-57-9
History
Namingafter Hassia, Latin for Hesse, Germany, where it was discovered[14]
DiscoveryGesellschaft für Schwerionenforschung (1984)
Isotopes of hassium
Main isotopes[15] Decay
abun­dance half-life (t1/2) mode pro­duct
269Hs synth 12 s α 265Sg
270Hs synth 7.6 s α 266Sg
271Hs synth 12 s α 267Sg
277mHs synth 130 s SF
 Category: Hassium
| references

Hassium is a chemical element; it has symbol Hs and atomic number 108. Hassium is highly radioactive: its most stable known isotopes have half-lives of approximately ten seconds.[a] One of its isotopes, 270Hs, has magic numbers of both protons and neutrons for deformed nuclei, which gives it greater stability against spontaneous fission. Hassium is a superheavy element; it has been produced in a laboratory only in very small quantities by fusing heavy nuclei with lighter ones. Natural occurrences of the element have been hypothesised but never found.

In the periodic table of elements, hassium is a transactinide element, a member of the 7th period and group 8; 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, reacting readily with oxygen to form a volatile tetroxide. The chemical properties of hassium have been only partly characterized, but they compare well with the chemistry of the other group 8 elements.

The principal innovation that led to the discovery of hassium was the technique of cold fusion, in which the fused nuclei did not differ by mass as much as in earlier techniques. It relied on greater stability of target nuclei, which in turn decreased excitation energy. This decreased the number of neutron ejections during synthesis, creating heavier, more stable resulting nuclei. The technique was first tested at the Joint Institute for Nuclear Research (JINR) in Dubna, Moscow Oblast, Russian SFSR, Soviet Union, in 1974. JINR used this technique to attempt synthesis of element 108 in 1978, in 1983, and in 1984; the latter experiment resulted in a claim that element 108 had been produced. Later in 1984, a synthesis claim followed from the Gesellschaft für Schwerionenforschung (GSI) in Darmstadt, Hesse, West Germany. The 1993 report by the Transfermium Working Group, formed by the International Union of Pure and Applied Chemistry and the International Union of Pure and Applied Physics, concluded that the report from Darmstadt was conclusive on its own whereas that from Dubna was not, and major credit was assigned to the German scientists. GSI formally announced they wished to name the element hassium after the German state of Hesse (Hassia in Latin), home to the facility in 1992; this name was accepted as final in 1997.

  1. ^ Hassium. The Periodic Table of Videos. University of Nottingham. 28 January 2011. Retrieved 19 October 2012.
  2. ^ "Radioactive Elements". Commission on Isotopic Abundances and Atomic Weights. 2018. Retrieved 20 September 2020.
  3. ^ Audi et al. 2017, p. 030001-136.
  4. ^ Hoffman, Lee & Pershina 2006, p. 1672.
  5. ^ a b Östlin, A. (2013). "Transition metals". Electronic Structure Studies and Method Development for Complex Materials (PDF) (Licentiate). pp. 15–16. Retrieved 24 October 2019.
  6. ^ Gyanchandani, Jyoti; Sikka, S. K. (10 May 2011). "Physical properties of the 6 d -series elements from density functional theory: Close similarity to lighter transition metals". Physical Review B. 83 (17): 172101. doi:10.1103/PhysRevB.83.172101.
  7. ^ Kratz; Lieser (2013). Nuclear and Radiochemistry: Fundamentals and Applications (3rd ed.). p. 631.
  8. ^ Hoffman, Darleane C.; Lee, Diana M.; Pershina, Valeria (2006). "Transactinides and the future elements". In Morss; Edelstein, Norman M.; Fuger, Jean (eds.). The Chemistry of the Actinide and Transactinide Elements (3rd ed.). Dordrecht, The Netherlands: Springer Science+Business Media. p. 1691. ISBN 978-1-4020-3555-5.
  9. ^ Fricke, Burkhard (1975). "Superheavy elements: a prediction of their chemical and physical properties". Recent Impact of Physics on Inorganic Chemistry. Structure and Bonding. 21: 89–144. doi:10.1007/BFb0116498. ISBN 978-3-540-07109-9. Retrieved 4 October 2013.
  10. ^ Düllmann, C. E. (2008). Investigation of group 8 metallocenes @ TASCA (PDF). 7th Workshop on Recoil Separator for Superheavy Element Chemistry TASCA 08. Archived from the original (PDF) on 30 April 2014. Retrieved 28 August 2020.
  11. ^ Hoffman, Lee & Pershina 2006, p. 1673.
  12. ^ Hoffman, Lee & Pershina 2006, p. 1691.
  13. ^ Robertson, M. (2011). "Chemical Data: Hassium". Visual Elements Periodic Table. Royal Society of Chemistry. Retrieved 28 November 2012.
  14. ^ Emsley, J. (2011). Nature's Building Blocks: An A–Z Guide to the Elements (New ed.). Oxford University Press. pp. 215–217. ISBN 978-0-19-960563-7.
  15. ^ Kondev, F. G.; Wang, M.; Huang, W. J.; Naimi, S.; Audi, G. (2021). "The NUBASE2020 evaluation of nuclear properties" (PDF). Chinese Physics C. 45 (3): 030001. doi:10.1088/1674-1137/abddae.


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