ELEMENTLE

Element 108 · Transition Metal

Hassium

Period 7 · Group 8

Hassium is a chemical element with symbol Hs and atomic number 108, named after 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 130 seconds. More than 100 atoms of hassium have been synthesized to date.

Three reasons Hassium stands out

  1. 1

    Synthetic element, named after birthplace of Goethe, a famous German polymath.

  2. 2

    Its most stable isotope has a half-life of about 9 seconds, making it one of the longer-lived superheavy elements.

  3. 3

    It was first created in 1984 by bombarding lead targets with iron nuclei.

A superheavy element with recognizable chemistry

Hassium is named for the German state of Hesse, home to the team that confirmed it. Researchers converted a few atoms into hassium tetroxide and detected the molecules after rapid transport. Its volatility resembled osmium tetroxide, a striking periodic relationship demonstrated atom by atom.

Hassium at a glance
Atomic number / protons108
SymbolHs
Family (Elementle)Transition Metal
Classification (PubChem)Transition metal
Period7
Group8
Atomic mass (u)269.1336
Standard stateBulk state not experimentally established
Electron configuration[Rn]7s2 5f14 6d6
Reported oxidation states8, 6, 5, 4, 3, 2
Electronegativity (Pauling)Not available
Atomic radius (pm)Not available
First ionization energy (eV)Not available
Electron affinity (eV)Not available
Density (g/cm³)Not available
Melting pointNot available
Boiling pointNot available
Discovery (PubChem)1984

Values are reference data, not a specification for every temperature, pressure, or allotrope. Unknown properties are left unavailable. Superheavy-element predictions remain uncertain.

Sources & further reading

PubChem: Hassium · Hassium on Wikipedia

The introduction and original editorial story are adapted from Wikipedia contributors via Periodic-Table-JSON. Element descriptions and their adaptations are available under CC BY-SA 3.0. Numerical attributes use the PubChem periodic-table dataset, retrieved September 22, 2026.