Isotopes of ununoctium

Ununoctium (Uuo) is an artificial element created in particle colliders, and thus a standard atomic mass cannot be given. Like all artificial elements, it has no stable isotopes. The first (and so far only) isotope to be synthesized was ²⁹⁴Uuo in 2006; it has a half-life of 890 microseconds.

Table

nuclide symbol	Z(p)	N(n)	isotopic mass (u)	half-life	decay mode(s)	daughter isotope(s)	nuclear spin
²⁹⁴Uuo	118	176	294.21392(71)#	890 µs	α	²⁹⁰Lv

Notes

Values marked # are not purely derived from experimental data, but at least partly from systematic trends.
Uncertainties are given in concise form in parentheses after the corresponding last digits. Uncertainty values from Ame2003 denote one standard deviation. Values from IUPAC are expanded uncertainties.

Theoretical

Theoretical calculations done on the synthetic pathways for, and the half-life of, other isotopes have shown that some could be slightly more stable than the synthesized isotope ²⁹⁴Uuo, most likely ²⁹³Uuo, ²⁹⁵Uuo, ²⁹⁶Uuo, ²⁹⁷Uuo, ²⁹⁸Uuo, ³⁰⁰Uuo and ³⁰²Uuo.^[1]^[2]^[2] Of these, ²⁹⁷Uuo, might provide the best chances for obtaining longer-lived nuclei,^[1]^[2] and thus might become the focus of future work with this element. Some isotopes with many more neutrons, such as some located around ³¹³Uuo, could also provide longer-lived nuclei.^[3]

Target-projectile combinations leading to Z=118 compound nuclei

The below table contains various combinations of targets and projectiles which could be used to form compound nuclei with Z=118.

Target	Projectile	CN	Attempt result
¹⁶⁰Gd	¹³⁶Xe	²⁹⁶Uuo	Reaction yet to be attempted
²⁰⁸Pb	⁸⁶Kr	²⁹⁴Uuo	Failure to date
²³²Th	⁶⁴Ni	²⁹⁶Uuo	Reaction yet to be attempted
²³⁸U	⁵⁸Fe	²⁹⁶Uuo	Reaction yet to be attempted
²⁴⁴Pu	⁵⁴Cr	²⁹⁸Uuo	Reaction yet to be attempted
²⁴⁸Cm	⁵⁰Ti	²⁹⁸Uuo	Reaction yet to be attempted
²⁵⁰Cm	⁵⁰Ti	³⁰⁰Uuo	Reaction yet to be attempted
²⁴⁹Cf	⁴⁸Ca	²⁹⁷Uuo	Successful reaction
²⁵²Cf	⁴⁸Ca	³⁰⁰Uuo	Reaction yet to be attempted
²⁵⁷Fm	⁴⁰Ar	²⁹⁷Uuo	Reaction yet to be attempted

Theoretical calculations on evaporation cross sections

The below table contains various targets-projectile combinations for which calculations have provided estimates for cross section yields from various neutron evaporation channels. The channel with the highest expected yield is given.

DNS = Di-nuclear system ; σ = cross section

Target	Projectile	CN	Channel (product)	σ _max	Model	Ref
²⁰⁸Pb	⁸⁶Kr	²⁹⁴Uuo	1n (²⁹³Uuo)	0.1 pb	DNS	^[4]
²⁰⁸Pb	⁸⁵Kr	²⁹³Uuo	1n (²⁹²Uuo)	0.18 pb	DNS	^[4]
²⁵²Cf	⁴⁸Ca	³⁰⁰Uuo	3n (²⁹⁷Uuo)	1.2 pb	DNS	^[5]
²⁵¹Cf	⁴⁸Ca	²⁹⁹Uuo	3n (²⁹⁶Uuo)	1.2 pb	DNS	^[5]
²⁴⁹Cf	⁴⁸Ca	²⁹⁷Uuo	3n (²⁹⁴Uuo)	0.3 pb	DNS	^[5]

References

Isotope masses from:
- M. Wang, G. Audi, A.H. Wapstra, F.G. Kondev, M. MacCormick, X. Xu et al. (2012). "The AME2012 atomic mass evaluation (II). Tables, graphs and references.". Chinese Physics C, 36 (12): 1603–2014. Bibcode:2012ChPhC..36....3M. doi:10.1088/1674-1137/36/12/003.
- G. Audi, A. H. Wapstra, C. Thibault, J. Blachot and O. Bersillon (2003). "The NUBASE evaluation of nuclear and decay properties". Nuclear Physics A 729 (1): 3–128. Bibcode:2003NuPhA.729....3A. doi:10.1016/j.nuclphysa.2003.11.001.

↑ 1.0 1.1 P. Roy Chowdhury, C. Samanta, and D. N. Basu (January 26, 2006). "α decay half-lives of new superheavy elements". Phys. Rev. C 73: 014612. arXiv:nucl-th/0507054. Bibcode:2006PhRvC..73a4612C. doi:10.1103/PhysRevC.73.014612. Retrieved 2008-01-18.
↑ 2.0 2.1 2.2 C. Samanta, P. Roy Chowdhury and D. N. Basu (April 6, 2007). "Predictions of alpha decay half lives of heavy and superheavy elements". Nuclear Physics A 789 (1-4): 142–154. arXiv:nucl-th/0703086. Bibcode:2007NuPhA.789..142S. doi:10.1016/j.nuclphysa.2007.04.001. Retrieved 2008-01-18.
↑ S B Duarte, O A P Tavares, M Gonçalves, O Rodríguez, F Guzmán, T N Barbosa, F García and A Dimarco (2004). "Half-life predictions for decay modes of superheavy nuclei". J. Phys. G: Nucl. Part. Phys. 30 (10): 1487–1494. Bibcode:2004JPhG...30.1487D. doi:10.1088/0954-3899/30/10/014. Retrieved 2008-01-18.
↑ 4.0 4.1 Feng, Zhao-Qing; Jin, Gen-Ming; Li, Jun-Qing; Scheid, Werner (2007). "Formation of superheavy nuclei in cold fusion reactions". Physical Review C 76 (4): 044606. arXiv:0707.2588. Bibcode:2007PhRvC..76d4606F. doi:10.1103/PhysRevC.76.044606.
↑ 5.0 5.1 5.2 Feng, Z; Jin, G; Li, J; Scheid, W (2009). "Production of heavy and superheavy nuclei in massive fusion reactions". Nuclear Physics A 816 (1-4): 33. arXiv:0803.1117. Bibcode:2009NuPhA.816...33F. doi:10.1016/j.nuclphysa.2008.11.003.

Isotopes of ununseptium	Isotopes of ununoctium	Isotopes of ununennium
Table of nuclides

Isotopes of the chemical elements
1 H																	2 He
3 Li	4 Be											5 B	6 C	7 N	8 O	9 F	10 Ne
11 Na	12 Mg											13 Al	14 Si	15 P	16 S	17 Cl	18 Ar
19 K	20 Ca	21 Sc	22 Ti	23 V	24 Cr	25 Mn	26 Fe	27 Co	28 Ni	29 Cu	30 Zn	31 Ga	32 Ge	33 As	34 Se	35 Br	36 Kr
37 Rb	38 Sr	39 Y	40 Zr	41 Nb	42 Mo	43 Tc	44 Ru	45 Rh	46 Pd	47 Ag	48 Cd	49 In	50 Sn	51 Sb	52 Te	53 I	54 Xe
55 Cs	56 Ba		72 Hf	73 Ta	74 W	75 Re	76 Os	77 Ir	78 Pt	79 Au	80 Hg	81 Tl	82 Pb	83 Bi	84 Po	85 At	86 Rn
87 Fr	88 Ra		104 Rf	105 Db	106 Sg	107 Bh	108 Hs	109 Mt	110 Ds	111 Rg	112 Cn	113 Uut	114 Fl	115 Uup	116 Lv	117 Uus	118 Uuo

		57 La	58 Ce	59 Pr	60 Nd	61 Pm	62 Sm	63 Eu	64 Gd	65 Tb	66 Dy	67 Ho	68 Er	69 Tm	70 Yb	71 Lu
		89 Ac	90 Th	91 Pa	92 U	93 Np	94 Pu	95 Am	96 Cm	97 Bk	98 Cf	99 Es	100 Fm	101 Md	102 No	103 Lr
Table of nuclides Categories: Isotopes Tables of nuclides Metastable isotopes Isotopes by element