Hassium (Hs)
Isotopes of Hassium
| Isotope | Atomic Mass | Half-life | Mode of Decay | Nuclear Spin | Nuclear Magnetic Moment |
| Hs-263 | 263.1287 | 1.00 second | α to Sg-259 | No data available | No data available |
| Hs-264 | 264.1284 | 0.00008 seconds | α to Sg-260; SF | No data available | No data available |
| Hs-265 | 265.13016 | 0.0018 seconds | α to Sg-261; SF | No data available | No data available |
| Hs-266 | 266.1300 | 0.033 seconds | α decay | No data available | No data available |
| Hs-267 | 267.1318 | 52.00 milliseconds | α to Sg-263; SF | No data available | No data available |
| Hs-268 | 268.1321 | 0.40 seconds | α decay | No data available | No data available |
| Hs-269 | 269.1341 | 9.30 seconds | α to Sg-265 | No data available | No data available |
| Hs-277 | 277 | 11.00 minutes | No data available | No data available | No data available |
Hassium is a synthetic element (an element that can be created in a laboratory but is not found in nature), officially discovered in 1984 by a German research team led by Peter Armbruster and Gottfried Münzenberg at the Institute for Heavy Ion Research (Gesellschaft für Schwerionenforschung - GSI) in Darmstadt, Germany. The team bombarded a target of Lead-208 with accelerated nuclei of Iron-58 to produce three atoms of the isotope Hassium-265. More than 100 atoms of hassium have been synthesized to date. The name hassium derives from the Latin name (Hassia) for the German state of Hesse, where the institute is located.
The chemical properties of hassium are characterized only partly, but they compare well with the chemistry of the other group 8 elements. It is expected to be a silvery metal that reacts readily with oxygen in the air, forming a volatile tetroxide. It is predicted to be a solid at room temperature and to crystallize in the hexagonal close-packed structure. It is expected to be the densest element of the first seven periods.
Properties of Hassium
| Name | Hassium |
| Symbol | Hs |
| Atomic number | 108 |
| Atomic weight | [277] (status unclear) |
| Standard state | Presumably a solid at 298 °K |
| CAS Registry ID | 54037-57-9 |
| Group in periodic table | 8 |
| Group name | None |
| Period in periodic table | 7 |
| Block in periodic table | d-block |
| Color | Unknown, but probably metallic and silvery white or grey in appearance |
| Classification | Metallic |
| Melting point | No data available |
| Boiling point | No data available |
| Density of solid | 28.6 g/cm3 (predicted) |
| Electron configuration | [Rn]5f146d67s2 |
