Unbiennium (Ube)
SuperactinideMasse atomique relative standard
N/DConfiguration électronique
[Og] 5g⁹ 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/DUnbiennium is the temporary systematic name for the hypothetical element with proton number 129. It has not been synthesized or observed in nature. Periodic-table extrapolations place it among the superheavy elements of the predicted eighth period, probably in the superactinide or g-block region. Its chemistry is expected to be strongly affected by relativistic and spin-orbit effects, so simple analogies with lighter elements are unreliable.
This element has not been synthesized or experimentally confirmed. All listed physicochemical properties are calculated, extrapolated, or model-dependent.
No atoms or macroscopic sample of unbiennium have been reported. Its appearance, density, melting point, crystal structure, and other bulk physical properties are unknown; published values, where given, are theoretical predictions only.
Unbiennium has no confirmed practical, commercial, medical, or industrial use. If it is ever produced, the first uses would be in nuclear-structure research, tests of superheavy-element synthesis, and decay-chain studies. Such work would involve individual atoms or very small numbers of atoms, not usable quantities of material. Any proposed applications based on unusual electronic structure remain speculative because no isotope or compound has been made.
No compounds of unbiennium are known. The element is expected to have very complex superheavy chemistry, with valence levels involving predicted 5g, 6f, 7d, and 8p orbitals rather than a simple main-group pattern. Oxidation states, ionic radii, bonding preferences, and ligand chemistry are therefore theoretical. Calculations may discuss possible halides, oxides, or molecular ions, but these are model species rather than experimentally characterized compounds.
No direct safety data exist for unbiennium. Any isotope made in a laboratory would almost certainly be radioactive and extremely scarce, so the principal hazard would be radiation from the atoms and their decay products rather than chemical toxicity of bulk material. Handling would be limited to shielded nuclear-research equipment designed for atom-at-a-time detection.
Unbiennium has no confirmed natural occurrence and no known environmental cycle. Because no isotope has been observed, its persistence, mobility, and chemical behavior in air, water, soil, or organisms are unknown. If produced experimentally, only isolated atoms would be generated, and they would decay or be retained within laboratory apparatus rather than enter the environment as a material flow.
Unbiennium has no commodity market, no practical supply chain, and no established demand outside possible basic research. Future production, if achieved, would require heavy-ion accelerator experiments using rare targets and intense beams, with expected yields far below macroscopic quantities. Costs would be dominated by accelerator operation, target preparation, detection systems, and repeated attempts at synthesis rather than by separable material value. Recycling or stockpiling is not meaningful for an element not yet made.
Unbiennium has not been detected in the universe. Standard models do not predict stable primordial quantities of such a high-proton element, and any isotopes formed in extreme nucleosynthetic events would be expected to be short-lived unless an unconfirmed island of enhanced stability includes suitable nuclei. Its extraterrestrial relevance is therefore theoretical.
- Ube is a temporary systematic symbol, not a permanent element name.
- The name unbiennium encodes the digits 1, 2, and 9 in IUPAC systematic nomenclature.
- Any confirmed isotope would probably be identified from a decay chain rather than by weighing a sample.
- Predicted chemistry may be less periodic than the name’s position suggests because nearby orbitals are closely spaced.
Images

Propriétés
Propriétés physiques
N/D
Propriétés chimiques
- Affinité électronique
- 0,5 eV
- Configuration électronique
- [Og] 5g⁹ 8s²
Propriétés thermodynamiques
N/D
Propriétés nucléaires
- Protons
- 129 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, 41, 18, 8, 2 Comparer : Électrons par couche de tous les éléments →
Identifiants
- Numéro CAS
- 54576-80-6 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