Oganesson
Element 118 · Noble Gas
Oganesson completes the seventh period and is the heaviest element ever synthesized. First produced in 2002 at Dubna and confirmed in 2006, only a few atoms have ever existed, each decaying within a millisecond. Despite its noble-gas position, theory predicts oganesson will be a reactive solid at room temperature because extreme relativistic effects distort its electron shells. No chemistry has been observed; all properties are predicted, with essentially no experimental data. Oganesson is intensely radioactive, with each atom decaying in about a millisecond.
Key facts
| Atomic number | 118 |
|---|---|
| Atomic weight | [294] |
| Category | Noble Gas |
| Group / Period | 18 / 7 |
| Block | p |
| Electron configuration | [Rn] 5f14 6d10 7s2 7p6 (predicted) |
| Common oxidation states | 0 (predicted) |
| State at STP | Solid |
Occurrence
Oganesson is entirely synthetic, made by fusing californium-249 with calcium-48 in accelerators.
Applications
Completing the periodic table's seventh period
Theoretical studies of relativistic electron behavior
No commercial applications
Common compounds
- Oganesson compounds (predicted, none observed)
Oganesson is only the second element named after a living person, honoring physicist Yuri Oganessian, leader of superheavy element research at Dubna.
Data source: IUPAC standard atomic weights 2021