#108 / 118
108Hs[277]
Superheavy / Unknownsolid at STPD-block

Hassium

Group: 8•Period: 7•Standard Atomic Weight: [277] u
Open Full Periodic TableView Bohr Model

Why is Hassium in this position?

Understanding the scientific rationale behind Hassium's position in the periodic table:

Group Assignment
Group 8

Belongs to Group 8 as the 6d homologue of Iron, Ruthenium, and Osmium (6d⁶ 7s²).

Period Assignment
Period 7

Belongs to Period 7 because its outermost electrons occupy n=7.

Orbital Block
D-block

Belongs to the d-block because its valence electrons fill 6d orbitals.

Chemical Category
Superheavy / Unknown

Classified as a superheavy transition metal capable of reaching the +8 oxidation state.

Atomic Structure & Bohr Shell Model

Shell Distribution: [2, 8, 18, 32, 32, 14, 2]

Bohr Atomic Shell Model(2, 8, 18, 32, 32, 14, 2)

Hover or tap any shell orbit ring to inspect electron counts and 2n² capacities.

108 Protons (p⁺)169 Neutrons (n⁰)
KShell K: Electron 1 of 2Shell K: Electron 2 of 2LShell L: Electron 1 of 8Shell L: Electron 2 of 8Shell L: Electron 3 of 8Shell L: Electron 4 of 8Shell L: Electron 5 of 8Shell L: Electron 6 of 8Shell L: Electron 7 of 8Shell L: Electron 8 of 8MShell M: Electron 1 of 18Shell M: Electron 2 of 18Shell M: Electron 3 of 18Shell M: Electron 4 of 18Shell M: Electron 5 of 18Shell M: Electron 6 of 18Shell M: Electron 7 of 18Shell M: Electron 8 of 18Shell M: Electron 9 of 18Shell M: Electron 10 of 18Shell M: Electron 11 of 18Shell M: Electron 12 of 18Shell M: Electron 13 of 18Shell M: Electron 14 of 18Shell M: Electron 15 of 18Shell M: Electron 16 of 18Shell M: Electron 17 of 18Shell M: Electron 18 of 18NShell N: Electron 1 of 32Shell N: Electron 2 of 32Shell N: Electron 3 of 32Shell N: Electron 4 of 32Shell N: Electron 5 of 32Shell N: Electron 6 of 32Shell N: Electron 7 of 32Shell N: Electron 8 of 32Shell N: Electron 9 of 32Shell N: Electron 10 of 32Shell N: Electron 11 of 32Shell N: Electron 12 of 32Shell N: Electron 13 of 32Shell N: Electron 14 of 32Shell N: Electron 15 of 32Shell N: Electron 16 of 32Shell N: Electron 17 of 32Shell N: Electron 18 of 32Shell N: Electron 19 of 32Shell N: Electron 20 of 32Shell N: Electron 21 of 32Shell N: Electron 22 of 32Shell N: Electron 23 of 32Shell N: Electron 24 of 32Shell N: Electron 25 of 32Shell N: Electron 26 of 32Shell N: Electron 27 of 32Shell N: Electron 28 of 32Shell N: Electron 29 of 32Shell N: Electron 30 of 32Shell N: Electron 31 of 32Shell N: Electron 32 of 32OShell O: Electron 1 of 32Shell O: Electron 2 of 32Shell O: Electron 3 of 32Shell O: Electron 4 of 32Shell O: Electron 5 of 32Shell O: Electron 6 of 32Shell O: Electron 7 of 32Shell O: Electron 8 of 32Shell O: Electron 9 of 32Shell O: Electron 10 of 32Shell O: Electron 11 of 32Shell O: Electron 12 of 32Shell O: Electron 13 of 32Shell O: Electron 14 of 32Shell O: Electron 15 of 32Shell O: Electron 16 of 32Shell O: Electron 17 of 32Shell O: Electron 18 of 32Shell O: Electron 19 of 32Shell O: Electron 20 of 32Shell O: Electron 21 of 32Shell O: Electron 22 of 32Shell O: Electron 23 of 32Shell O: Electron 24 of 32Shell O: Electron 25 of 32Shell O: Electron 26 of 32Shell O: Electron 27 of 32Shell O: Electron 28 of 32Shell O: Electron 29 of 32Shell O: Electron 30 of 32Shell O: Electron 31 of 32Shell O: Electron 32 of 32PShell P: Electron 1 of 14Shell P: Electron 2 of 14Shell P: Electron 3 of 14Shell P: Electron 4 of 14Shell P: Electron 5 of 14Shell P: Electron 6 of 14Shell P: Electron 7 of 14Shell P: Electron 8 of 14Shell P: Electron 9 of 14Shell P: Electron 10 of 14Shell P: Electron 11 of 14Shell P: Electron 12 of 14Shell P: Electron 13 of 14Shell P: Electron 14 of 14QShell Q: Electron 1 of 2Shell Q: Electron 2 of 2HsZ = 108

Educational Note: This Niels Bohr planetary model visually illustrates principal quantum energy shells ($n=1, 2, 3\dots$) and electron counts. In modern quantum mechanics (Schrödinger model), electrons do not orbit in fixed circular planetary tracks, but exist as 3D probability clouds (orbitals: $s, p, d, f$) governed by the Heisenberg uncertainty principle.

Electron Shell Filling Breakdown

Shell K (n=1):2 / 2 electrons (100%)
Shell L (n=2):8 / 8 electrons (100%)
Shell M (n=3):18 / 18 electrons (100%)
Shell N (n=4):32 / 32 electrons (100%)
Shell O (n=5):32 / 50 electrons (64%)
Shell P (n=6):14 / 72 electrons (19%)
Shell Q (n=7):2 / 98 electrons (2%)
Aufbau Electron Configuration
1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 4f¹⁴ 5s² 5p⁶ 5d¹⁰ 5f¹⁴ 6s² 6p⁶ 6d⁶ 7s²

Neutral ground state configuration. Valence electrons: 8.

Atomic & Quantum Properties

Electronegativity (Pauling)Not available
1st Ionization Energy730 kJ/mol
Electron AffinityNot available
Atomic Radius (empirical)134 pm
Common Oxidation States+8
Crystal StructureHCP (predicted)

Physical & Thermal Properties

Density at STP40.7 g/cm³ (predicted)
Melting Point2700 °C (2973 K)
Boiling Point6200 °C (6473 K)
Magnetic OrderingParamagnetic
Discovery Year1984
Discovered ByGSI Helmholtz Centre for Heavy Ion Research (Darmstadt, Germany)

Real-World Uses, Occurrence & Compounds

Major Industrial & Everyday Uses
  • Pure scientific research into maximum oxidation states of superheavy elements
Occurrence in Nature

Synthesized in accelerators by bombarding Lead-208 with Iron-58 heavy ions.

Etymology & Name Origin

From 'Hassia', the Latin name for the German federal state of Hesse where GSI is located

Important Chemical Compounds
HsO₄ (Hassium tetroxide, volatile gas in the +8 state)
Interesting Chemical Facts
  • • In 2001, scientists at GSI reacted single atoms of hassium with oxygen gas to synthesize Hassium tetroxide (HsO₄), confirming the +8 oxidation state in a superheavy element.
  • • Theoretical physics models predict hassium would be the densest element on the entire periodic table (approx. 41 g/cm³) if macroscopic quantities could exist.
  • • The longest-lived isotope, Hassium-270, has a half-life of roughly 10 seconds.
Safety & Handling Note

Intensely radioactive; produced only in microscopic cyclotron collisions.

Explore Neighborhood Elements

Same Group (Group 8):
#26Fe#44Ru#76Os
Same Period (Period 7):
#87Fr#88Ra#89Ac#90Th#91Pa#92U#93Np#94Pu#95Am#96Cm#97Bk#98Cf#99Es#100Fm#101Md#102No#103Lr#104Rf#105Db#106Sg#107Bh#109Mt#110Ds#111Rg#112Cn#113Nh#114Fl#115Mc#116Lv#117Ts#118Og