Hassium is a radioactive element produced in accelerator reactions, including collisions involving lead and iron nuclei. Its name refers to the German state associated with the discovery laboratory. It is studied through specialized experiments on tiny amounts, rather than through ordinary bulk-material handling.
FROM ELEMENT TO APPLICATION
AN ELEMENT IN CONTEXT
What can deposition of a hassium oxide reveal about chemical behavior?
Hassium tetroxide in thermochromatography
FOLLOW THIS RELATIONSHIP
Identify the transported species
The research examines a volatile hassium oxide rather than a bulk metal. Its chemical form is central to interpreting how the material is transported and observed.
Explore the model (optional)
HsFORM → INTERACTION → CONSEQUENCE
Follow the explanation in either direction. These are authored steps, not a physical clock.
Optional: check your understanding
USE THE EXPLANATION
Which distinction is essential in interpreting the experiment?
Atomic identity, reference properties and structure models
INTERACTIVE 3D108 visible sites
An electron censusDrag to rotate · scroll or pinch to zoom
[Rn] 5f14 6d6 7s2. Grouping electrons by principal shell connects the neutral-atom configuration to periodic-table patterns.
What this representation means
A three-dimensional counting diagram. Dots are count markers, not measured electron positions; spherical placement and spacing are arbitrary. There are no electron trajectories here. Orbitals describe quantum states.
For superheavy elements, this configuration is a theoretical assignment. It does not establish measured bulk chemistry or a material state.
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HISTORY & HUMAN DISCOVERY
A regional name and a volatile molecule
Hassium was discovered at GSI in 1984 and named for the German state of Hesse, where the laboratory is located. The name became internationally established in the 1997 settlement. Later experiments identified a volatile , turning a position beneath osmium into a testable chemical relationship. Hassium therefore illustrates two kinds of progress: proving that a exists and observing how its permit it to combine with another element.
1984
Discovery
GSI experiments establish element 108.
2001
Chemical investigation
GSI researchers observe formation of a volatile hassium tetroxide.
Hassium is an artificially produced element studied in small numbers of radioactive atoms. It has no established natural deposit and no ordinary commercial supply. The availability of a suitable determines whether a chemical experiment can be attempted; counting a and characterizing a compound require different experimental opportunities.
The neutral configuration is predicted, but formation of a volatile tetroxide has experimental support. This connects hassium with osmium’s group 8 chemistry. The result concerns a particular molecule, not a measured boiling point for elemental hassium. Nuclear stability and chemical volatility remain distinct properties of different parts of the system.
Each section links its supporting references. Descriptions and diagrams were authored for this atlas. Source checks completed. Source checks dated 2026-09-06.
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Family labels and the group-3 layout are teaching conventions. A table position does not establish an unknown bulk property. Electronic configurations refer to neutral atoms; ions and material environments require their own account.
Read each reference property together with its units, conditions and the reference information below.
Not yet recorded: electron affinity, second ionization energy, ground-state term symbol, van der waals radius, thermal conductivity, specific heat capacity, electrical resistivity, crystal structure, lattice parameter a, space group, abundance in seawater, abundance in the universe, annual production, supply-risk listing, hazard classification, biological role, cas registry number, pubchem cid, wikidata item. These families are declared and awaiting an ingestion run against the source each names; they are listed here rather than shown as empty rows.
Physical
Intended reference: CRC Handbook of Chemistry and Physics · CRC Press
Phase at 20 °C
Not recorded
293.15 K, 101.325 kPa
Melting point
Not recorded
at standard pressure unless noted
Boiling point
Not recorded
101.325 kPa
Density
Not recorded
solids and liquids at 293 K; gases at 273 K and 101.325 kPa
Atomic and electronic
Intended reference: Pauling electronegativity scale · Widely tabulated; original in The Nature of the Chemical Bond
Electronegativity
Not recorded
Pauling scale
First ionization energy
Not recorded
gas-phase neutral atom, ground state
Covalent radius
Not recorded
single-bond covalent radius
Common oxidation states
Not recorded
states met in ordinary compounds; not exhaustive
Occurrence and identity
Intended reference: CRC Handbook of Chemistry and Physics · CRC Press
Abundance in the crust
Not recorded
upper continental crust, mass fraction
Has stable isotopes
Noderived
Discovery year in CE
1984 CEderived
WHERE IT SITS AMONG ITS NEIGHBORS
Electronegativity across period 7
Ra 0.9 Pauling · Radium
Electronegativity across period 7. Exact values.
Ra
0.9
Ac
1.1
Th
1.3
Pa
1.5
U
1.38
Np
1.36
Pu
1.28
Am
1.13
Cm
1.28
Bk
1.3
Cf
1.3
Es
1.3
Fm
1.3
Md
1.3
No
1.3
Lr
1.3
Electronegativity down group 8
Fe 1.83 Pauling · Iron
Electronegativity down group 8. Exact values.
Fe
1.83
Ru
2.2
Os
2.2
The trend uses the same reference-property values as the periodic table. Elements with no recorded value are left out of the line rather than drawn at zero.
