Unbibium

Unbibium, ₁₂₂Ubb
Theoretical element
Unbibium
Pronunciation	/ˌuːnbaɪˈbaɪəm/ ⓘ (OON-by-BY-əm)
Alternative names	element 122, eka-thorium
Unbibium in the periodic table
	unbiunium ← unbibium → unbitrium
Atomic number (Z)	122
Group	g-block groups (no number)
Period	period 8 (theoretical, extended table)
Block	g-block
Electron configuration	predictions vary, see text
Physical properties
Phase at STP	unknown
Atomic properties
Oxidation states	common: (none); (+4)
Ionization energies	1st: 545 (predicted) kJ/mol ; 2nd: 1090 (predicted) kJ/mol ; 3rd: 1848 (predicted) kJ/mol ; ;
Other properties
CAS Number	54576-73-7
History
Naming	IUPAC systematic element name

Unbibium, also known as element 122 or eka-thorium, is a hypothetical chemical element; it has placeholder symbol Ubb and atomic number 122. Unbibium and Ubb are the temporary systematic IUPAC name and symbol respectively, which are used until the element is discovered, confirmed, and a permanent name is decided upon. In the periodic table of the elements, it is expected to follow unbiunium as the second element of the superactinides and the fourth element of the 8th period. Similarly to unbiunium, it is expected to fall within the range of the island of stability, potentially conferring additional stability on some isotopes, especially ³⁰⁶Ubb which is expected to have a magic number of neutrons (184).

Despite several attempts, unbibium has not yet been synthesized, nor have any naturally occurring isotopes been found to exist. There are currently no plans to attempt to synthesize unbibium. In 2008, it was claimed to have been discovered in natural thorium samples,^[3] but that claim has now been dismissed by recent repetitions of the experiment using more accurate techniques.

Chemically, unbibium is expected to show some resemblance to cerium and thorium. However, relativistic effects may cause some of its properties to differ; for example, it is expected to have a ground state electron configuration of [Og] 7d¹ 8s² 8p¹ or [Og] 8s² 8p², despite its predicted position in the g-block superactinide series.^[1]

^ ^a ^b Pyykkö, Pekka (2011). "A suggested periodic table up to Z ≤ 172, based on Dirac–Fock calculations on atoms and ions". Physical Chemistry Chemical Physics. 13 (1): 161–8. Bibcode:2011PCCP...13..161P. doi:10.1039/c0cp01575j. PMID 20967377.
^ ^a ^b Eliav, E.; Fritzsche, S.; Kaldor, U. (2015). "Electronic structure theory of the superheavy elements". Nuclear Physics A. 944 (December 2015): 518–550. Bibcode:2015NuPhA.944..518E. doi:10.1016/j.nuclphysa.2015.06.017.
^ Marinov, A.; Rodushkin, I.; Kolb, D.; et al. (2010). "Evidence for a long-lived superheavy nucleus with atomic mass number A=292 and atomic number Z=~122 in natural Th". International Journal of Modern Physics E. 19 (1): 131–140. arXiv:0804.3869. Bibcode:2010IJMPE..19..131M. doi:10.1142/S0218301310014662. S2CID 117956340.

[Pyykkö2011-1] Pyykkö, Pekka (2011). "A suggested periodic table up to Z ≤ 172, based on Dirac–Fock calculations on atoms and ions". Physical Chemistry Chemical Physics. 13 (1): 161–8. Bibcode:2011PCCP...13..161P. doi:10.1039/c0cp01575j. PMID 20967377.

[Eliav1-2] Eliav, E.; Fritzsche, S.; Kaldor, U. (2015). "Electronic structure theory of the superheavy elements". Nuclear Physics A. 944 (December 2015): 518–550. Bibcode:2015NuPhA.944..518E. doi:10.1016/j.nuclphysa.2015.06.017.

[arxiv-3] Marinov, A.; Rodushkin, I.; Kolb, D.; et al. (2010). "Evidence for a long-lived superheavy nucleus with atomic mass number A=292 and atomic number Z=~122 in natural Th". International Journal of Modern Physics E. 19 (1): 131–140. arXiv:0804.3869. Bibcode:2010IJMPE..19..131M. doi:10.1142/S0218301310014662. S2CID 117956340.

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