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Oganesson

Element 118 · Noble gas

Specimen

Atomic number
118
Atomic mass
[294]
State at room temperature
Unknown
Melting point
Unknown
Boiling point
Unknown
Density
Unknown
Discovered
2006

Mass number of the longest-lived isotope, from IUPAC.1 Other physical data from PubChem.2

Can I eat it?

In food and water
Never made in amounts you could eat. Only a few atoms of oganesson have ever been made. Each atom lasts less than one millisecond. 34

See every element.

The atom

Og
ShellElectrons
1 (K) 2
2 (L) 8
3 (M) 18
4 (N) 32
5 (O) 32
6 (P) 18
7 (Q) outermost 8
Total118

Configuration [Rn] 5f¹⁴ 6d¹⁰ 7s² 7p⁶

5f ↑ ↓ ↑ ↓ ↑ ↓ ↑ ↓ ↑ ↓ ↑ ↓ ↑ ↓
6d ↑ ↓ ↑ ↓ ↑ ↓ ↑ ↓ ↑ ↓
7s ↑ ↓
7p ↑ ↓ ↑ ↓ ↑ ↓
A shell diagram: each ring is an electron shell and each dot is one electron. The nucleus holds 118 protons. The outermost shell is shown in red. Electrons do not travel on rings: they fill orbitals, regions where an electron is likely to be found. The boxes are those orbitals for the electrons outside the Rn core, with one arrow per electron. This configuration is a prediction; it has not been measured.

Related elements

Group 18
He Helium Ne Neon Ar Argon Kr Krypton Xe Xenon Rn Radon

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Sources

  1. 1

    IUPAC Commission on Isotopic Abundances and Atomic Weights (CIAAW), 2024. Radioactive Elements .

    Mass number and half-life of the longest-lived isotope of the 34 elements with no standard atomic weight.

  2. 2

    National Center for Biotechnology Information (PubChem), 2026. Periodic Table of Elements .

    Electron configuration, melting and boiling points, density and discovery year for all 118 elements.

  3. 3

    Contemporary Physics Education Project, Lawrence Berkeley National Laboratory, 2018. Nuclear Science: A Guide to the Nuclear Science Wall Chart, Chapter 8: The Search for Heavy Elements , p. 8-4 and 8-8.

    • scientists discovered elements 104 through 118. Only a few atoms of these new elements were produced in
  4. 4

    Los Alamos National Laboratory, Periodic Table of Elements, 2026. Oganesson .

    • Oganesson is highly radioactive and has an extremely short half-life (0.69 milliseconds!).