Isotopes of darmstadtium

Darmstadtium (Ds) 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 ²⁶⁹Ds in 1994. There are 7 or 8 known radioisotopes from ²⁶⁷Ds (or ²⁶⁹Ds) to ²⁸¹Ds (with many gaps) and 2 or 3 known isomers. The longest-lived isotope is ²⁸¹Ds with a half-life of 9.6 seconds.

Table

nuclide symbol	Z(p)	N(n)	isotopic mass (u)	half-life	decay mode(s)[n 1]	daughter isotope(s)	nuclear spin
	excitation energy
267Ds[n 2]	110	157	267.14434(39)#	3(+6-2) µs			9/2+#
269Ds	110	159	269.14512(15)#	230(110) µs [179(+245-66) µs]	α	265Hs	3/2+#
270Ds	110	160	270.14472(31)#	160(100) µs [0.10(+14-4) ms]	α	266Hs	0+
270mDs	1140(70) keV			10(6) ms [6.0(+82-22) ms]	α	266Hs	(10)(-#)
271Ds	110	161	271.14606(11)#	210(170) ms	α	267Hs	11/2-#
271mDs	29(29) keV			1.3(5) ms	α	267Hs	9/2+#
273Ds	110	163	273.14886(14)#	0.17(+17-6) ms	α	269Hs	13/2-#
277Ds[n 3]	110	167	277.15565(104)#	5# s	α	273Hs	11/2+#
279Ds[n 4]	110	169	279.15886(80)#	0.18(+5-3) s	SF (90%)	(various)
					α (10%)	275Hs
281Ds[n 5]	110	171	281.16206(78)#	9.6 s	SF (94%)	(various)	3/2+#
					α (6%)	277Hs
281mDs[n 6][n 5]					α	277Hs

1. ^ Abbreviations:
   SF: Spontaneous fission
2. ^ Unconfirmed isotope
3. ^ Not directly synthesized, occurs in decay chain of ²⁸⁵Uuq
4. ^ Not directly synthesized, occurs as decay product of ²⁸³Cn
5. ^ ^{a b} Not directly synthesized, occurs in decay chain of ²⁸⁹Uuq
6. ^ 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. 

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