Oganesson vs Ununennium
Side-by-side comparison of Oganesson (Og, element 118) and Ununennium (Uue, element 119) by atomic structure and physical properties.
Predicted
Ununennium (Uue) Near-real
This element is actively being synthesized in laboratories (Russia, Japan, USA). Its existence is theoretically confirmed, and discovery is expected in the coming years.
This element has not been synthesized or experimentally confirmed. All listed physicochemical properties are calculated, extrapolated, or model-dependent.
| Property | Og Oganesson | Uue Ununennium Predicted |
|---|---|---|
| Atomic number | 118 | 119 |
| Symbol | Og | Uue |
| Name | Oganesson | Ununennium |
| Category | noble-gas | Superactinide |
| Standard Atomic Weight | 294 u | Not established |
| Period | 7 | 8 |
| Group | 18 | 1 |
| Block | p | s |
| Phase at STP | Gas | Not established |
| Electron configuration | [Rn]5f146d107s27p6 (Predicted) | [Og]8s1 |
| Oxidation states | [-1, 0, 1, 2, 4, 6] | ["+1","+3"] |
| Electronegativity (Pauling) | N/A | 0.86 |
| Electron affinity | 0.08 eV | 0.25 eV |
| Density | 7000 kg/m³ | 3 kg/m³ |
| Melting point | N/A | Not established |
| Boiling point | -243.15 °C | Not established |
| Discovery year | 2006 | Not established |
Key Differences
| Property | Og Oganesson | Uue Ununennium |
|---|---|---|
| Density | 7000 kg/m³ ↑ higher | 3 kg/m³ ↓ lower |
| Electron affinity | 0.08 eV ↓ lower | 0.25 eV ↑ higher |
| Period | 7 | 8 |
| Group | 18 | 1 |
| Block | p | s |
| Category | noble-gas | Superactinide |
| Electron configuration | [Rn]5f146d107s27p6 (Predicted) | [Og]8s1 |
What Can Be Compared?
Elements beyond oganesson (118) have not been synthesized, so most physicochemical properties cannot be compared experimentally. For them, only identity data is available: systematic IUPAC name, symbol, atomic number, and predicted periodic-table placement (period, group, block, electron configuration).