Isotopes of copernicium

Copernicium (Cn) 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 ²⁷⁷Cn in 1996. There are 6 known radioisotopes and 2 possible isomers. The longest-lived isotope is ²⁸³Cn with a half-life of 4.2 minutes.

Table

nuclide symbol	Z(p)	N(n)	isotopic mass (u)	half-life	decay mode(s)[n 1]	daughter isotope(s)	nuclear spin
	excitation energy
277Cn	112	165	277.16394(14)#	1.1(7) ms [0.69(+69-24) ms]	α	273Ds	3/2+#
281Cn	112	169	281.16929(106)#	10# s	α	277Ds	3/2+#
282Cn	112	170	282.16977(76)#	30# s	SF	(various)	0+
283Cn	112	171	283.17179(83)#	4.2(2.1) min	α (80%)	279Ds
					SF (20%)	(various)
283mCn[n 2]				5 min	SF	(various)
284Cn	112	172	284.17238(91)#	31(18) s	SF	(various)	0+
285Cn	112	173	285.17411(78)#	29 s	α	281Ds	5/2+#
285mCn[n 2]				8.9 min	α	281Ds

1. ^ Abbreviations:
   SF: Spontaneous fission
2. ^ ^{a b} This isomer is unconfirmed

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.

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 roentgenium	Isotopes of copernicium	Isotopes of ununtrium
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