Oganesson was created by colliding calcium-48 with californium-249 and identifying the resulting decay events. Its position in group 18 is a classification, not evidence that a visible sample is an ordinary noble gas. Its properties require a clear distinction between measured nuclear events and theoretical predictions.
FROM ELEMENT TO APPLICATION
AN ELEMENT IN CONTEXT
What does identifying oganesson-294 establish about the limits of nuclear survival?
Oganesson-294 in synthesis and decay research
FOLLOW THIS RELATIONSHIP
Specify the observed nuclear species
The research concerns oganesson-294 rather than an unspecified collection of all possible oganesson nuclei. Its isotope identity matters because neutron number contributes to nuclear behavior alongside proton number.
Explore the model (optional)
OgFORM → INTERACTION → CONSEQUENCE
Follow the explanation in either direction. These are authored steps, not a physical clock.
Optional: check your understanding
USE THE EXPLANATION
Which conclusion goes beyond the evidence described here?
Atomic identity, reference properties and structure models
INTERACTIVE 3D118 visible sites
An electron censusDrag to rotate · scroll or pinch to zoom
[Rn] 5f14 6d10 7s2 7p6. 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 completed period with chemistry still to discover
The Dubna–Livermore collaboration published synthesis evidence for element 118 in 2006. International recognition followed in 2015 and the name oganesson was approved in 2016, honoring Yuri Oganessian’s contributions to superheavy-element research. Its place closes period seven, but a completed row is not a completed scientific description. The element’s have been observed, while the chemistry and material behavior implied by its position remain subjects for careful theoretical investigation.
2006
Synthesis report published
The collaboration publishes correlated decay evidence for element 118.
2016
Name approved
Oganesson, Og, is approved following recognition of the discovery in 2015.
Oganesson is produced artificially and identified through extremely scarce radioactive events. It has no established natural material resource, ordinary commercial supply or macroscopic specimen. The existence of a detected nucleus establishes an ; it does not provide enough atoms to observe a gas, liquid or solid directly.
The neutral configuration is predicted. Its filled outer shell places oganesson in group 18, yet relativistic calculations predict substantial departures from lighter noble-gas behavior. No bulk phase or ordinary chemical inertness has been directly measured. Group membership therefore frames a research question instead of guaranteeing the properties of a familiar gas.
Each section links its supporting references. Descriptions and diagrams were authored for this atlas. Source checks completed. Source checks dated 2026-09-06.
CITE THIS PAGE
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
2006 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 18
Kr 3 Pauling · Krypton
Electronegativity down group 18. Exact values.
Kr
3
Xe
2.6
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.
