Isotopes of ununquadium

Ununquadium (Uuq) is an artificial element, and thus a standard atomic mass cannot be given. Like all artificial elements, it has no stable isotopes. The first isotope to be synthesized was ²⁸⁹Uuq in 1999 (or possibly 1998). Ununquadium has five confirmed isotopes, and possibly 2 nuclear isomers. The longest-lived isotope is ²⁸⁹Uuq with a half-life of 2.6 seconds.

Table

nuclide symbol	Z(p)	N(n)	isotopic mass (u)	half-life	decay mode(s)^{[n 1]}	daughter isotope(s)	nuclear spin
nuclide symbol	excitation energy			half-life	decay mode(s)^{[n 1]}	daughter isotope(s)	nuclear spin
²⁸⁵Uuq	114	171	285.18370(111)#	125 ms	α	²⁸¹Cn	3/2+#
²⁸⁶Uuq^{[n 2]}	114	172	286.18386(83)#	130 ms	SF (60%)^{[n 3]}	(variable)	0+
²⁸⁶Uuq^{[n 2]}	114	172	286.18386(83)#	130 ms	α (40%)	²⁸²Cn	0+
²⁸⁷Uuq	114	173	287.18560(83)#	510(+180-100) ms	α	²⁸³Cn
^287mUuq^{[n 4]}				5.5s	α	²⁸³Cn
²⁸⁸Uuq	114	174	288.18569(91)#	.8(+27-16) s	α	²⁸⁴Cn	0+
²⁸⁹Uuq	114	175	289.18728(79)#	2.6(+12-7) s	α	²⁸⁵Cn	5/2+#
^289mUuq^{[n 4]}				1.1 min	α	²⁸⁵Cn

^ Abbreviations:
SF: Spontaneous fission
^ Not directly synthesized, produced in decay chain of ²⁹⁴Uuo
^ Heaviest nuclide known to undergo spontaneous fission
^ ^a ^b Existence of this isomer is uncertain

Notes

Values marked # are not purely derived from experimental data, but at least partly from systematic trends. Spins with weak assignment arguments are enclosed in parentheses.
Uncertainties are given in concise form in parentheses after the corresponding last digits. Uncertainty values denote one standard deviation, except isotopic composition and standard atomic mass from IUPAC which use expanded uncertainties.
It is theorized that ²⁹⁸Uuq will have a relatively long half-life

References

Isotope masses from:
- 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: 3–128. Bibcode 2003NuPhA.729....3A. doi:10.1016/j.nuclphysa.2003.11.001. http://www.nndc.bnl.gov/amdc/nubase/Nubase2003.pdf.
Isotopic compositions and standard atomic masses from:
- J. R. de Laeter, J. K. Böhlke, P. De Bièvre, H. Hidaka, H. S. Peiser, K. J. R. Rosman and P. D. P. Taylor (2003). "Atomic weights of the elements. Review 2000 (IUPAC Technical Report)". Pure and Applied Chemistry 75 (6): 683–800. doi:10.1351/pac200375060683. http://www.iupac.org/publications/pac/75/6/0683/pdf/.
- M. E. Wieser (2006). "Atomic weights of the elements 2005 (IUPAC Technical Report)". Pure and Applied Chemistry 78 (11): 2051–2066. doi:10.1351/pac200678112051. http://iupac.org/publications/pac/78/11/2051/pdf/. Lay summary.
Half-life, spin, and isomer data selected from the following sources. See editing notes on this article's talk page.
- 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: 3–128. Bibcode 2003NuPhA.729....3A. doi:10.1016/j.nuclphysa.2003.11.001. http://www.nndc.bnl.gov/amdc/nubase/Nubase2003.pdf.
- National Nuclear Data Center. "NuDat 2.1 database". Brookhaven National Laboratory. http://www.nndc.bnl.gov/nudat2/. Retrieved September 2005.
- N. E. Holden (2004). "Table of the Isotopes". In D. R. Lide. CRC Handbook of Chemistry and Physics (85th ed.). CRC Press. Section 11. ISBN 978-0849304859.

Isotopes of ununtrium	Isotopes of ununquadium	Isotopes of ununpentium
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