#118 / 118
118Og[294]
Superheavy / Unknownsolid at STPP-block

Oganesson

Group: 18•Period: 7•Standard Atomic Weight: [294] u
Open Full Periodic TableView Bohr Model

Why is Oganesson in this position?

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

Group Assignment
Group 18

Belongs to Group 18 as the heaviest noble gas homologue, completing the 7s² 7p⁶ valence shell.

Period Assignment
Period 7

Belongs to Period 7 because its electrons completely fill the seventh principal energy level.

Orbital Block
P-block

Belongs to the p-block as the final 7p element.

Chemical Category
Superheavy / Unknown

Classified as a superheavy element completing the seventh row of Mendeleev's periodic table.

Atomic Structure & Bohr Shell Model

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

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

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

118 Protons (p⁺)176 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 18Shell P: Electron 2 of 18Shell P: Electron 3 of 18Shell P: Electron 4 of 18Shell P: Electron 5 of 18Shell P: Electron 6 of 18Shell P: Electron 7 of 18Shell P: Electron 8 of 18Shell P: Electron 9 of 18Shell P: Electron 10 of 18Shell P: Electron 11 of 18Shell P: Electron 12 of 18Shell P: Electron 13 of 18Shell P: Electron 14 of 18Shell P: Electron 15 of 18Shell P: Electron 16 of 18Shell P: Electron 17 of 18Shell P: Electron 18 of 18QShell Q: Electron 1 of 8Shell Q: Electron 2 of 8Shell Q: Electron 3 of 8Shell Q: Electron 4 of 8Shell Q: Electron 5 of 8Shell Q: Electron 6 of 8Shell Q: Electron 7 of 8Shell Q: Electron 8 of 8OgZ = 118

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):18 / 72 electrons (25%)
Shell Q (n=7):8 / 98 electrons (8%)
Aufbau Electron Configuration
1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 4f¹⁴ 5s² 5p⁶ 5d¹⁰ 5f¹⁴ 6s² 6p⁶ 6d¹⁰ 7s² 7p⁶

Neutral ground state configuration. Valence electrons: 8.

Atomic & Quantum Properties

Electronegativity (Pauling)Not available
1st Ionization Energy860.1 kJ/mol
Electron Affinity-5.4 kJ/mol
Atomic Radius (empirical)152 pm
Common Oxidation States+4, +2, 0
Crystal StructureFCC (predicted)

Physical & Thermal Properties

Density at STP5.0 g/cm³ (predicted solid)
Melting Point50 °C (323 K)
Boiling Point80 °C (353 K)
Magnetic OrderingDiamagnetic
Discovery Year2002
Discovered ByJoint Institute for Nuclear Research (Dubna) & Lawrence Livermore National Lab

Real-World Uses, Occurrence & Compounds

Major Industrial & Everyday Uses
  • Frontier scientific exploration of the ultimate limits of the periodic table and nuclear existence
Occurrence in Nature

Synthesized in heavy-ion cyclotrons by bombarding Californium-249 targets with Calcium-48 ions.

Etymology & Name Origin

Named in honor of Russian nuclear physicist Yuri Oganessian, pioneer of superheavy element synthesis

Important Chemical Compounds
None (only 5 or 6 individual atoms ever detected)
Interesting Chemical Facts
  • • Oganesson is the heaviest known element on the periodic table and completes the entire 7th period (all 118 elements).
  • • Yuri Oganessian is only the second person in history (after Glenn Seaborg) to have a chemical element named after him while still living.
  • • Although situated in Group 18 with the noble gases, relativistic 'electron smearing' delocalizes its valence electrons, predicting that Oganesson is a solid semiconductor at room temperature rather than a gas!
Safety & Handling Note

Extremely radioactive; decays in less than a millisecond via alpha emission.

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