Unbiunium (Ubu)
SuperactinideMasse atomique relative standard
N/DConfiguration électronique
[Og] 5g¹ 8s²Point de fusion
N/DPoint d’ébullition
N/DMasse volumique
N/DÉtats d’oxydation
N/DÉlectronégativité (Pauling)
N/DÉnergie d’ionisation (1re)
N/DAnnée de découverte
N/DRayon atomique
N/DUnbiunium is the temporary systematic name for element 121, symbol Ubu. It has not been confirmed by synthesis, and all chemical data are theoretical. In extended periodic-table models it is placed just beyond elements 119 and 120, often as an early superactinide or eka-actinium-like element. Relativistic electronic effects are expected to shape its valence chemistry, probably making the +3 state important, but no atom has been chemically studied.
This element has not been synthesized or experimentally confirmed. All listed physicochemical properties are calculated, extrapolated, or model-dependent.
No macroscopic sample of unbiunium exists, and its appearance has not been observed. Any description of color, luster, density, melting point, or crystal structure is only a theoretical prediction for a substance not yet made in bulk.
Unbiunium has no confirmed practical or commercial use. If produced, it would be made atom by atom for nuclear-physics research, mainly to test models of superheavy nuclei, shell stabilization, and decay chains beyond the known elements. Any chemical use is precluded by the absence of isolable quantities and by the expected short half-lives of accessible isotopes.
No compound of unbiunium has been prepared. Calculations generally treat it as a very heavy electropositive element whose chemistry may resemble an expanded version of actinium-group behavior, with Ubu³⁺ likely to be a significant ionic form. Hypothetical compounds such as unbiunium trifluoride (UbuF₃), unbiunium trichloride (UbuCl₃), or unbiunium oxide (Ubu₂O₃) are model species, not known substances. Lower oxidation states may be affected by relativistic stabilization of outer p orbitals, but their stability is uncertain.
There are no measured toxicological or radiological data for unbiunium. Any isotope that might be synthesized would be a superheavy radionuclide, with hazards determined by its isotope-specific half-life and decay modes. Realistic handling would be in shielded accelerator facilities at atom-at-a-time quantities, so radiation from the product atoms would be a research-control issue rather than an industrial exposure scenario.
Unbiunium has no confirmed natural occurrence and no observed environmental cycle. If individual atoms were formed artificially and released, their behavior would be dominated by radioactive decay long before ordinary geochemical transport could be characterized. Environmental properties such as solubility, sorption, and bioavailability are therefore unknown and only inferable from theoretical chemistry.
Unbiunium has no commodity market, no commercial supply chain, and no recycling stream. Production, if achieved, would require a heavy-ion accelerator, rare target material, and highly sensitive decay detection, with yields expected to be at the level of individual atoms. Costs would be those of fundamental nuclear research rather than material production. Substitution and demand are not meaningful because no technological application has been established.
No isotope of unbiunium is known in nature or in extraterrestrial material. Superheavy nuclei near this region may be discussed in models of rapid neutron-capture nucleosynthesis and the island of stability, but confirmed long-lived nuclides of element 121 are not known. Any primordial abundance, if it ever existed, is expected to be negligible unless unexpectedly long-lived isotopes exist.
- Unbiunium is a temporary systematic IUPAC name, not a discovery name.
- The temporary symbol Ubu would change if the element were officially named.
- No isotope of element 121 has a measured half-life.
- Predicted chemistry depends strongly on relativistic electronic structure.
- Element 121 is often discussed as an early superactinide.
- No confirmed natural atom of unbiunium has been reported.
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Propriétés
Propriétés physiques
N/D
Propriétés chimiques
- Affinité électronique
- 0,5 eV
- Configuration électronique
- [Og] 5g¹ 8s²
Propriétés thermodynamiques
N/D
Propriétés nucléaires
- Protons
- 121 Comparer : Protons de tous les éléments →
- Isotopes connus
- 0 Comparer : Isotopes connus de tous les éléments →
- Isotopes stables
- 0 Comparer : Isotopes stables de tous les éléments →
- Présence à l’état naturel
- Non observé
Abondance
N/D
Sécurité
- Radioactif
- Oui
Structure cristalline
N/D
Structure électronique
- Électrons par couche
- 2, 8, 18, 32, 33, 18, 8, 2 Comparer : Électrons par couche de tous les éléments →
Identifiants
- Numéro CAS
- 54899-56-8 Comparer : Numéro CAS de tous les éléments →
Configuration électronique Prédit
——Données de configuration électronique indisponibles pour cet ion.
Modèle atomique
Les isotopes diffèrent par leur nombre de neutrons, leur masse et leur stabilité — pas par la configuration électronique de l’atome neutre.
N/D
Modèle atomique schématique, non à l’échelle.
Empreinte atomique
Spectre d’émission / d’absorption
Distribution isotopique
Aucun isotope stable.
| Nombre de masse | Masse atomique (u) | Abondance naturelle | Demi-vie |
|---|
Phase / État
Données de phase ou d’état indisponibles
N/D
Données de phase ou d’état indisponibles