Hassium

Hassium is a synthetic chemical element with symbol Hs and atomic number 108. It is named after the German state of Hesse. It is a synthetic element and radioactive; the most stable known isotope, 270Hs, has a half-life of approximately 10 seconds. 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. Hassium is a member of the 7th period and belongs to the group 8 elements: it is thus the sixth member of the 6d series of transition metals. 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. (source)