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About Hassium

Hassium Bohr

Hassium, atomic number 108, is a synthetic transactinide element. Though early experiments in the late 1970's by the Russian research team of Yuri Oganessian and Vladimir Utyonkov at the Joint Institute for Nuclear Research, it is unclear from available data whether they were successful. The official discovery of Hassium has been credited to the German research team of Peter Armbruster and Gottfried Münzenberg at the Institute for Heavy Ion Research in 1984. The naming of hassium was a contentious one, and wasn’t resolved until 1997, when the IUPAC gave in to the discovering team's desire to name the element for the German state of Hessen, where the Institute for Heavy Ion Research (GSI) is located.

Though hassium's instability has precluded extensive study of its chemical properties, many of these can be predicted from its location on the periodic table. As a member of the group 8 elements, it is expected to have properties similar to those of the platinum group elements, especially its closest homologue osmium. Notably, hassium is predicted to have a density higher than any of the known elements, nearly double the density of osmium, which has the highest density that has been measured. Like many other unstable synthetic elements, hassium is studied extensively in basic science research settings, but lacks any practical applications.

Hassium Properties

Hassium Bohr ModelHassium is a D-Block, Group 8, Period 7 element. The number of electrons in each of hassium's shells is 2, 8, 18, 32, 32, 14, 2 and its electron configuration is [Rn] 5f146d6 7s2. In its elemental form, hassium's CAS number is 54037-57-9. Hassium's appearance is unknown but it is suspected to be silvery white or metallic grey in color. Hassium is a synthetic element that is not present in the environment. Little is known about the element and it has no known uses. Hassium was first created in 1984 by a team headed by Peter Armbruster and Gottfried Münzenberg at the Heavy Ion Research Laboratory in Darmstadt, Germany. Its name is derived from the Latin word "Hassias" meaning "Hess," after the German state.

Hassium information, technical data, properties, and other useful facts are detailed below. Scientific facts, such as the atomic structure and ionization energy are included.

Symbol: Hs
Atomic Number: 108
Atomic Weight: 277
Element Category: transition metal
Group, Period, Block: 8, 7, d
Color: unknown (presumably metallic/ silvery white/ gray)
Other Names: Hassio
Melting Point: N/A
Boiling Point: N/A
Density: 41 kg·cm3 (predicted)
Liquid Density @ Melting Point: N/A
Density @ 20°C: N/A
Density of Solid: 28600 (predicted) kg·m3
Specific Heat: N/A
Superconductivity Temperature: N/A
Triple Point: N/A
Critical Point: N/A
Heat of Fusion (kJ·mol-1): N/A
Heat of Vaporization (kJ·mol-1): N/A
Heat of Atomization (kJ·mol-1): N/A
Thermal Conductivity: N/A
Thermal Expansion: N/A
Electrical Resistivity: N/A
Tensile Strength: N/A
Molar Heat Capacity: N/A
Young's Modulus: N/A
Shear Modulus: N/A
Bulk Modulus: N/A
Poisson Ratio: N/A
Mohs Hardness: N/A
Vickers Hardness: N/A
Brinell Hardness: N/A
Speed of Sound: N/A
Pauling Electronegativity: N/A
Sanderson Electronegativity: N/A
Allred Rochow Electronegativity: N/A
Mulliken-Jaffe Electronegativity: N/A
Allen Electronegativity: N/A
Pauling Electropositivity: N/A
Reflectivity (%): N/A
Refractive Index: N/A
Electrons: 108
Protons: 108
Neutrons: 157
Electron Configuration: [Rn] 5f146d6 7s2
Atomic Radius: 126 pm (estimated)
Atomic Radius,
non-bonded (Å):
Covalent Radius: 134 pm (estimated)
Covalent Radius (Å): 1.34
Van der Waals Radius: N/A
Oxidation States: 8, 6, 5, 4, 3, 2 (predicted)
Phase: Solid (predicted)
Crystal Structure: N/A
Magnetic Ordering: N/A
Electron Affinity (kJ·mol-1) Unknown
1st Ionization Energy: 733.3 kJ·mol-1(estimated)
2nd Ionization Energy: 1756.0 kJ·mol-1(estimated)
3rd Ionization Energy: 2827.0 kJ·mol-1(estimated)
CAS Number: 54037-57-9
EC Number: N/A
MDL Number: N/A
Beilstein Number: N/A
SMILES Identifier: N/A
InChI Identifier: N/A
InChI Key: N/A
PubChem CID: N/A
ChemSpider ID: N/A
Earth - Total: N/A
Mercury - Total: N/A
Venus - Total: N/A
Earth - Seawater (Oceans), ppb by weight: N/A
Earth - Seawater (Oceans), ppb by atoms: N/A
Earth -  Crust (Crustal Rocks), ppb by weight: N/A
Earth -  Crust (Crustal Rocks), ppb by atoms: N/A
Sun - Total, ppb by weight: N/A
Sun - Total, ppb by atoms: N/A
Stream, ppb by weight: N/A
Stream, ppb by atoms: N/A
Meterorite (Carbonaceous), ppb by weight: N/A
Meterorite (Carbonaceous), ppb by atoms: N/A
Typical Human Body, ppb by weight: N/A
Typical Human Body, ppb by atom: N/A
Universe, ppb by weight: N/A
Universe, ppb by atom: N/A
Discovered By: Peter Armbruster and Gottfried Münzenber
Discovery Date: 1984
First Isolation: N/A

Hassium Isotopes

Hassium (Hs) is an artificial element. Like all artificial elements, it has no stable isotopes.

Nuclide Isotopic Mass Half-Life Mode of Decay Nuclear Spin Magnetic Moment Binding Energy (MeV) Natural Abundance
(% by atom)
263Hs 263.12856(37)# 1# ms a to 259Sg 7/2+# N/A 1891.72 -
264Hs 264.12839(5) 540(300) µs a to 260Sg; SF 0+ N/A 1899.8 -
265Hs 265.13009(15)# 2.1(3) ms [2.0(+3-2) ms] a to 261Sg; SF 9/2+# N/A 1898.56 -
266Hs 266.13010(31)# 2.7(10) ms [2.3(+13-6) ms] a to 262Sg 0+ N/A 1906.64 -
267Hs 267.13179(11)# 32(15) ms a to 263Sg; SF 3/2+# N/A 1914.72 -
268Hs 268.13216(44)# 2# s a to 264Sg 0+ N/A 1922.8 -
269Hs 269.13406(13)# 27(17) s a to 265Sg N/A N/A 1930.88 -
270Hs 270.13465(31)# 3.6(+8-14) s a to 266Sg 0+ N/A 1938.96 -
271Hs 271.13766(36)# 40# s a to 267Sg N/A N/A 1947.03 -
272Hs 272.13905(62)# 40# s Unknown 0+ N/A 1955.11 -
273Hs 273.14199(89)# 50# s a to 269Sg (3/2+)# N/A 1953.88 -
274Hs 274.14313(70)# 1# min Unknown 0+ N/A 1961.95 -
275Hs 275.14595(77)# 0.15(+27-6) s a to 271Sg N/A N/A 1970.03 -
276Hs 276.14721(89)# 1# h Unknown 0+ N/A 1978.11 -
277Hs 277.14984(78)# 40(30) min SF 3/2+# N/A 1986.19 -