Hassium

Hassium (Hs) is a chemical element with atomic number 108. It is one of the superheavy elements not found naturally in the Earth, produced only in particle accelerators designed to collide atomic nuclei. All of its isotopes are radioactive and decay rapidly.

Because only small quantities of atoms are produced—sometimes just a few—the properties of hassium are estimated by comparison with elements in its group and by theoretical calculation. It is placed in group 8 of the periodic table, in the same period as osmium and iron, and is classified as a transition metal.

Discovery and naming

Hassium was first synthesized in 1984 at the GSI heavy-ion research centre in Darmstadt, Germany, by a team led by Peter Armbruster and Gottfried Münzenberg. The method used was to bombard a lead target with high-velocity iron ions, causing the two nuclei to fuse and produce a new, heavier nucleus.

The name comes from "Hassia," the Latin name for the German state of Hesse, where the GSI centre is located. The name was formally adopted in the early 1990s, following a dispute over the naming priority of the superheavy elements.

Nuclear properties

Several isotopes of hassium have been created. The heavier ones, with more neutrons, generally have longer half-lives than lighter ones. The known isotopes have half-lives ranging from milliseconds to several microseconds. Decay occurs mainly through alpha decay and spontaneous fission.

Chemistry

Although only small amounts of atoms are available, researchers have been able to conduct single-atom chemical experiments. It has been shown that hassium can form a light oxide gas that behaves similarly to osmium oxide. This result supported the correct placement of hassium in group 8 and demonstrated that the periodic table's trends continue to apply even for the superheavy elements.

Applications

Hassium has no commercial or industrial use. Its significance lies in basic research: understanding the stability of heavy nuclei and investigating the theory of the "island of stability," a region where superheavy nuclei with long half-lives are predicted to exist.