Hassium

  • hassium, 108hs
    hassium
    pronunciationm/ (about this soundlisten)[1] (hass-ee-əm)
    mass number[269]
    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
    blockd-block
    element category  transition metal
    electron configuration[rn] 5f14 6d6 7s2[2]
    electrons per shell2, 8, 18, 32, 32, 14, 2
    physical properties
    phase at stpsolid (predicted)[3]
    density (near r.t.)41 g/cm3 (predicted)[4]
    atomic properties
    oxidation states(+2), (+3), (+4), (+6), +8[4][5][6] (brackets: prediction)
    ionization energies
    • 1st: 730 kj/mol
    • 2nd: 1760 kj/mol
    • 3rd: 2830 kj/mol
    • (more) (predicted)[7]
    atomic radiusempirical: 126 pm (estimated)[4]
    covalent radius134 pm (estimated)[8]
    other properties
    natural occurrencesynthetic
    crystal structurehexagonal close-packed (hcp)
    hexagonal close-packed crystal structure for hassium

    (predicted)[3]
    cas number54037-57-9
    history
    namingafter hassia, latin for hesse, germany, where it was discovered[9]
    discoverygesellschaft für schwerionenforschung (1984)
    main isotopes of hassium
    iso­tope abun­dance half-life (t1/2) decay mode pro­duct
    269hs syn 16 s α 265sg
    270hs syn 9 s α 266sg
    271hs syn 10 s α 267sg
    category category: hassium
    | references

    hassium is a chemical element with the symbol hs and the atomic number 108. hassium is highly radioactive; the most stable known isotope, 269hs, has a half-life of approximately 16 seconds. 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 has been made only in laboratories in minuscule quantities; its possible occurrence in nature has been hypothesized but no natural hassium has been found so far.

    the first attempts to synthesize element 108 were made in two different experiments at the joint institute for nuclear research (jinr) in dubna, moscow oblast, russian sfsr, soviet union, in 1978. more attempts were made at the same venue in 1983 and then in 1984; the latter resulted in a claim that element 108 had been produced. later in 1984, an attempt was made at the gesellschaft für schwerionenforschung (gsi) in darmstadt, hesse, west germany, which claimed to have synthesized it. 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 the report from darmstadt was more conclusive on its own and the major credit was assigned to the german scientists, who then chose the name hassium after the german state of hesse.

    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, in group 8, reacting readily with oxygen to form a volatile tetroxide. the chemical properties of hassium have only been partly characterized but they compare well with the chemistry of the other group 8 elements.

  • introduction
  • discovery
  • natural occurrence
  • isotopes
  • predicted properties
  • experimental chemistry
  • notes
  • references
  • bibliography

Hassium, 108Hs
Hassium
Pronunciationm/ (About this soundlisten)[1] (HASS-ee-əm)
Mass number[269]
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
Blockd-block
Element category  Transition metal
Electron configuration[Rn] 5f14 6d6 7s2[2]
Electrons per shell2, 8, 18, 32, 32, 14, 2
Physical properties
Phase at STPsolid (predicted)[3]
Density (near r.t.)41 g/cm3 (predicted)[4]
Atomic properties
Oxidation states(+2), (+3), (+4), (+6), +8[4][5][6] (brackets: prediction)
Ionization energies
  • 1st: 730 kJ/mol
  • 2nd: 1760 kJ/mol
  • 3rd: 2830 kJ/mol
  • (more) (predicted)[7]
Atomic radiusempirical: 126 pm (estimated)[4]
Covalent radius134 pm (estimated)[8]
Other properties
Natural occurrencesynthetic
Crystal structurehexagonal close-packed (hcp)
Hexagonal close-packed crystal structure for hassium

(predicted)[3]
CAS Number54037-57-9
History
Namingafter Hassia, Latin for Hesse, Germany, where it was discovered[9]
DiscoveryGesellschaft für Schwerionenforschung (1984)
Main isotopes of hassium
Iso­tope Abun­dance Half-life (t1/2) Decay mode Pro­duct
269Hs syn 16 s α 265Sg
270Hs syn 9 s α 266Sg
271Hs syn 10 s α 267Sg
Category Category: Hassium
| references

Hassium is a chemical element with the symbol Hs and the atomic number 108. Hassium is highly radioactive; the most stable known isotope, 269Hs, has a half-life of approximately 16 seconds. 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 has been made only in laboratories in minuscule quantities; its possible occurrence in nature has been hypothesized but no natural hassium has been found so far.

The first attempts to synthesize element 108 were made in two different experiments at the Joint Institute for Nuclear Research (JINR) in Dubna, Moscow Oblast, Russian SFSR, Soviet Union, in 1978. More attempts were made at the same venue in 1983 and then in 1984; the latter resulted in a claim that element 108 had been produced. Later in 1984, an attempt was made at the Gesellschaft für Schwerionenforschung (GSI) in Darmstadt, Hesse, West Germany, which claimed to have synthesized it. 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 the report from Darmstadt was more conclusive on its own and the major credit was assigned to the German scientists, who then chose the name hassium after the German state of Hesse.

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, in group 8, reacting readily with oxygen to form a volatile tetroxide. The chemical properties of hassium have only been partly characterized but they compare well with the chemistry of the other group 8 elements.