Oganesson
noble gasProperties
| Property | Value |
|---|---|
| Atomic Mass | 294 amu |
| Category | noble gas |
| Group | 18 |
| Period | 7 |
| Electron Configuration | [Rn] 5f14 6d10 7s2 7p6 |
| Oxidation States | 6, 4, 2, 1, 0, -1 |
| Discovered By | Joint Institute for Nuclear Research (Dubna), Lawrence Livermore National Laboratory (2002) |
About Oganesson
Oganesson sits at the bottom-right corner of the periodic table and is the heaviest element anyone has ever made — five or six confirmed atoms, all produced by smashing calcium-48 into californium-249 at Dubna. Its longest-lived isotope, ²⁹⁴Og, decays through alpha emission with a half-life around 0.69 ms, so nobody has ever observed its bulk properties; everything we say about them comes from relativistic Dirac-Hartree-Fock calculations. Those calculations are the interesting part. Even though Og lives in group 18 below radon, the relativistic contraction on the 7s and 7p₁/₂ orbitals is so severe that the usual noble-gas picture breaks down. Calculations predict an unusually polarizable atom, a positive electron affinity (no other noble gas has one), and an electron density that smears toward a Thomas-Fermi-like distribution rather than discrete shells. It may even be a solid semiconductor at room temperature. Whether any of this is testable depends on building isotopes that live long enough to do chemistry on.
Fun Fact
Oganesson is the only element named after a living scientist at the time of naming (2016) since seaborgium in 1997 — Yuri Oganessian, born in 1933, led the research program that synthesized six of the newest elements on the periodic table.
Common Uses
- Probing the predicted breakdown of noble-gas behavior under extreme relativistic effects
- Mapping the upper edge of the periodic table toward the predicted island of stability
- Benchmarking Dirac-Hartree-Fock calculations against measured decay properties
- Hot-fusion reaction studies with ⁴⁸Ca + ²⁴⁹Cf at Dubna and Oak Ridge
- No commercial use — total atoms produced is in the single digits