Atomic Properties of Og
- Atomic Number of Og
- 118
- Atomic Mass of Og
- 294.0000 u
- Electron Configuration
- [Rn] 5f14 6d10 7s2 7p6
- Electronegativity
- —
- Block
- p-block
- Group
- 18
- Period
- 7
Oganesson exists because a calcium-48 nucleus and a californium-249 nucleus occasionally fused in an accelerator experiment. Researchers at JINR in Dubna, working with Lawrence Livermore scientists, reported the synthesis in 2002. Detectors followed alpha decay and spontaneous fission from a few atoms of element 118. No one observed a speck, bubble, or visible flash.
The name honors nuclear physicist Yuri Oganessian. Its position places it below radon in group 18, but that address cannot supply measured bulk properties. Oganesson-294 has a half-life below a millisecond, and only a few atoms have been produced. Density, melting point, color, and ordinary chemical behavior remain predictions.
Those predictions are unusually interesting. In such a heavy atom, inner electrons move at speeds where relativistic effects strongly reshape electron energies. Calculations suggest oganesson may be more reactive than conventional noble gases and could be a solid under ordinary conditions. Other models describe an unusually diffuse electron distribution. These are testable theoretical results, not observations of a sample.
The measured decay chain matters independently of any future chemistry. It tests models of how superheavy nuclei balance attractive nuclear forces against electrical repulsion among 118 protons. Researchers also search for longer-lived neighboring isotopes that might approach an island of enhanced nuclear stability. Oganesson has no practical application beyond this research.
The final Still One is not a gas confirmed to be strange. It is a set of fleeting nuclear events occupying a chemically suggestive position. Its honest story keeps three layers separate: synthesis was observed, decay was measured, and almost everything about a room-temperature material is calculated.