Isotopes of seaborgium

Seaborgium (Sg) has no stable isotopes. A standard atomic mass cannot be given, though the atomic mass of the most stable isotope is approx. 266.12.

Table

nuclide symbol	Z(p)	N(n)	isotopic mass (u)	half-life	nuclear spin	representative isotopic composition (mole fraction)	range of natural variation (mole fraction)
	excitation energy
258Sg	106	152	258.11317(45)#	3.3(10) ms [2.9(+13-7) ms]	0+
259Sg	106	153	259.11450(19)#	580(210) ms [0.48(+28-13) s]	1/2+#
260Sg	106	154	260.11442(4)	3.8(8) ms	0+
261Sg	106	155	261.11612(14)#	230(60) ms	7/2+#
262Sg	106	156	262.1164(3)#	8(3) ms [6.9(+38-18) ms]	0+
263Sg	106	157	263.11832(13)#	1.0(2) s	9/2+#
263mSg	100(70)# keV			120 ms	3/2+#
264Sg	106	158	264.11893(30)#	0.4# s	0+
265Sg	106	159	265.12111(6)	8(3) s	3/2+#
266Sg	106	160	266.12207(31)#	21(6) s	0+
267Sg	106	161	267.12443(29)#	19 ms
268Sg	106	162	268.12561(58)#	30# s	0+
269Sg	106	163	269.12876(70)#	35(23) s
270Sg	106	164	270.13033(66)#	10# min	0+
271Sg	106	165	271.13347(70)#	2.4(+43-10) min
272Sg	106	166	272.13516(82)#	1# h	0+
273Sg	106	167	273.13822(71)#	1# min

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 Ame2003 Atomic Mass Evaluation by G. Audi, A.H. Wapstra, C. Thibault, J. Blachot and O. Bersillon in Nuclear Physics A729 (2003).
• Isotopic compositions and standard atomic masses from Atomic weights of the elements. Review 2000 (IUPAC Technical Report). Pure Appl. Chem. Vol. 75, No. 6, pp. 683–800, (2003) and Atomic Weights Revised (2005).
• Half-life, spin, and isomer data selected from these sources. Editing notes on this article's talk page.
  • Audi, Bersillon, Blachot, Wapstra. The Nubase2003 evaluation of nuclear and decay properties, Nuc. Phys. A 729, pp. 3–128 (2003).
  • National Nuclear Data Center, Brookhaven National Laboratory. Information extracted from the NuDat 2.1 database (retrieved Sept. 2005).
  • David R. Lide (ed.), Norman E. Holden in CRC Handbook of Chemistry and Physics, 85th Edition, online version. CRC Press. Boca Raton, Florida (2005). Section 11, Table of the Isotopes.