Hassium
Atomic Data
| Atomic Number | 108 |
| Symbol | Hs |
| Atomic Weight | 277 u |
| Density (STP) | N/A |
| Melting Point | N/A °C (None K) |
| Boiling Point | N/A °C (None K) |
| Electronegativity | : |
| Electron Config. | 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d10 5f14 6s2 6p6 6d6 7s2 |
| Oxidation States | +8 |
| Phase at STP | Solid |
| Category | Transition Metal |
| Period / Group | 7 / 8 |
| CAS Number | 54037-57-9 |
Electron Configuration
[Rn] 5f14 6d6 7s2
| Shell | n | Subshell | Electrons | Cumulative |
|---|---|---|---|---|
| K | 1 | 1s | 2 | 2 |
| L | 2 | 2s | 2 | 4 |
| L | 2 | 2p | 6 | 10 |
| M | 3 | 3s | 2 | 12 |
| M | 3 | 3p | 6 | 18 |
| M | 3 | 3d | 10 | 28 |
| N | 4 | 4s | 2 | 30 |
| N | 4 | 4p | 6 | 36 |
| N | 4 | 4d | 10 | 46 |
| N | 4 | 4f | 14 | 60 |
| O | 5 | 5s | 2 | 62 |
| O | 5 | 5p | 6 | 68 |
| O | 5 | 5d | 10 | 78 |
| O | 5 | 5f | 14 | 92 |
| P | 6 | 6s | 2 | 94 |
| P | 6 | 6p | 6 | 100 |
| P | 6 | 6d | 6 | 106 |
| Q | 7 | 7s | 2 | 108 |
| Total | 108 | 108 | ||
Isotopes of Hassium
Hassium has two naturally occurring stable isotopes. The most abundant is ²⁷⁰Hs, comprising None% of all naturally occurring Hassium.
| Isotope | Symbol | Protons | Neutrons | Abundance | Stability |
|---|---|---|---|---|---|
| Hassium-270 | ²⁷⁰Hs | 108 | 162 | trace | Stable |
| Hassium-277 | ²⁷⁷Hs | 108 | 169 | trace | Stable |
Abundance & Occurrence
Hassium is present in Earth's crust at approximately trace amounts by mass and at approximately trace amounts by mass throughout the universe.
Earth's Crust (ppm by mass)
Universe (ppm by mass)
Discovery & History
Read more about the discovery of the periodic table of elements →
Safety & Handling
- Alpha radiation: Hassium isotopes are alpha emitters; Hs-269 (t½ = 16 s) was used in the 2002 chemical characterisation experiment: the brevity of available time demonstrates the extreme difficulty and hazard of working with such short-lived isotopes.
- No bulk hazard: Only a few hundred atoms of hassium have ever been made; there is no macroscopic radiological or chemical hazard from the element.
- Osmium tetroxide analogy: Hassium is predicted to form HsO4 analogous to the highly toxic OsO4; while quantities are far too small to pose practical danger, this analogy guides the protective measures used in characterisation experiments.
- Regulatory controls: All hassium research is conducted at licensed heavy ion accelerator facilities under comprehensive radiation protection.
Hassium in the Real World
Real-World Uses
- Superheavy element chemistry: Hassium (Hs-269, Hs-270) is the heaviest element whose chemistry has been studied experimentally; gas-phase chemistry confirms it forms HsO₄ (hassium tetroxide), a volatile compound analogous to OsO₄, validating Group 8 chemical periodicity at Z=108.
- Nuclear stability studies: Hs-270 has a half-life of about 22 seconds, making it relatively long-lived for a superheavy element; decay spectroscopy of hassium isotopes provides benchmarks for nuclear models in the region approaching the predicted island of stability.
- No commercial applications: Hassium is produced a few atoms per experiment; no practical application outside fundamental research is conceivable at current or foreseeable production rates.
Downloadable Resources
Free periodic table reference sheets for classrooms, study sessions, and laboratory use.
Frequently Asked Questions
Has hassium ever been used for anything?
No. Hassium has no practical applications. Its most stable isotope (Hs-269) has a half-life of about 16 seconds. It exists only as individual atoms produced in particle accelerators. Chemical experiments have been performed with single atoms of hassium, confirming it behaves like osmium (its lighter group 8 analogue): specifically, hassium tetroxide forms in a way analogous to osmium tetroxide.
How many atoms of hassium have been made?
Only a few atoms of hassium have ever been produced at any one time. The chemistry experiments performed on hassium involved just 7 atoms in the original 2002 study by Düllmann and colleagues at PSI (Paul Scherrer Institute). This is considered a remarkable achievement in chemistry: determining the properties of an element from just a handful of atoms.
Is hassium radioactive?
Yes, all isotopes of hassium are radioactive. The most stable known, Hs-269, has a half-life of about 16 seconds. It decays by alpha emission. All hassium atoms are produced and decay within moments of creation in particle accelerator experiments.
How did hassium get its name?
Hassium was named after Hassia, the Latin name for the German state of Hesse, where GSI Helmholtz Centre for Heavy Ion Research (Gesellschaft für Schwerionenforschung) is located. GSI is where hassium was first synthesised in 1984 by a team led by Peter Armbruster and Gottfried Münzenberg. The name was approved by IUPAC in 1997.