Hassium

General properties
Name, symbol, number	hassium, Hs, 108
Element category	transition metal
Group, period, block	8, 7, d
Standard atomic weight	(269)
Electron configuration	[Rn] 5f14 6d6 7s2 (predicted) 2, 8, 18, 32, 32, 14, 2 (predicted)
History
Discovery	Gesellschaft für Schwerionenforschung (1984)

Hassium is a chemical element with symbol Hs and atomic number 108, named in honor of the German state of Hesse. It is a synthetic element (an element that can be created in a laboratory but is not found in nature) and radioactive; the most stable known isotope, ²⁶⁹Hs, has a half-life of approximately 9.7 seconds, although an unconfirmed metastable state, ^277mHs, may have a longer half-life of about 11 minutes. More than 100 atoms of hassium have been synthesized to date.

In the periodic table of the elements, it is a d-block transactinide element. It is a member of the 7th period and belongs to the group 8 elements. Chemistry experiments have confirmed that hassium behaves as the heavier homologue to osmium in group 8. The chemical properties of hassium are characterized only partly, but they compare well with the chemistry of the other group 8 elements. In bulk quantities, hassium is expected to be a silvery metal that reacts readily with oxygen in the air, forming a volatile tetroxide.

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