HS

Hs, with the chemical symbol Hs and atomic number 108, is a synthetic transactinide element. It lies in period 7 of the periodic table and is part of the d-block, in group 8. Hassium has no stable isotopes and has only been observed in extremely small quantities produced in laboratory experiments; its isotopes decay rapidly, limiting opportunities for detailed study.

Discovery and naming

Hassium was first synthesized in 1984 by researchers at the GSI Helmholtz Centre for Heavy Ion Research in Darmstadt, Germany, by bombarding a lead-208 target with chromium-54 ions in a fusion-evaporation reaction. The element was named hassium in honor of the German state of Hesse (Hessen). The name hassium and the symbol Hs were officially sanctioned by IUPAC, reflecting its position as a heavier homologue in group 8.

Production and properties

As a very short-lived, artificially produced element, hassium atoms are created only in extremely small numbers—typically a few atoms at a time—and decay within milliseconds to seconds. Because of this, only limited experimental data exist on its physical and chemical properties. Theoretical and comparative studies suggest that hassium should share some chemical characteristics with its lighter group-8 neighbors, such as ruthenium and osmium, but reliable measurements are lacking. Consequently, its chemistry is largely inferred from trends in the periodic table rather than observed directly.

Applications and research

Hassium has no practical applications due to its transient existence. It is of interest primarily to nuclear and theoretical chemists and physicists studying the properties of superheavy elements, the behavior of nuclei at extreme proton and neutron numbers, and the boundaries of the periodic table.