hassium

Hassium (Hs) is a synthetic chemical element with the symbol Hs and atomic number 108. It is a transactinide metal in the seventh period of the periodic table and is positioned in group 8, where it is expected to share chemical characteristics with osmium. No stable isotopes of hassium exist.

Hassium was first synthesized in 1984 by researchers at the GSI Helmholtz Centre for Heavy Ion Research in Darmstadt, Germany, using fusion-evaporation reactions that combine heavy ions with a lead or bismuth target. The element’s name derives from the German state of Hesse (Hessen).

Like all transactinides, hassium is highly unstable and radioactive. All confirmed isotopes are short-lived, with half-lives ranging from milliseconds to perhaps seconds. The heavier isotopes decay into lighter elements through alpha decay or spontaneous fission. No practical quantities can be produced for everyday use.

Because of the rarity and short lifetimes of hassium atoms, detailed chemical properties are known only from a few exploratory experiments and theoretical calculations. Relativistic effects are expected to influence its chemistry, and early work suggests it could form compounds similar to those of its lighter homologs, though with notable deviations from lighter group 8 elements.

Applications are limited to basic research aimed at understanding the chemistry of superheavy elements and testing models of atomic structure under extreme relativistic conditions. Hassium remains a subject of study in nuclear physics and quantum chemistry, with experiments generally focused on measuring decay properties and producing new isotopes for study.