Isotopes of roentgenium

Roentgenium (Rg) has no stable isotopes. A standard atomic mass cannot be given.

Roentgenium has also been called eka-gold.

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)
nuclide symbol	excitation energy			half-life	nuclear spin	representative isotopic composition (mole fraction)	range of natural variation (mole fraction)
²⁷²Rg	111	161	272.15362(36)#	2.0(8) ms [3.8(+14-8) ms]	5+#,6+#
²⁷³Rg	111	162	273.15368(65)#	5# ms
²⁷⁴Rg	111	163	274.15571(66)#	6.4(+307-29) ms
²⁷⁵Rg	111	164	275.15614(74)#	10# ms
²⁷⁶Rg	111	165	276.15849(67)#	100# ms
²⁷⁷Rg	111	166	277.15952(66)#	1# s
²⁷⁸Rg	111	167	278.16160(68)#	1# s
²⁷⁹Rg	111	168	279.16247(71)#	0.17(+81-8) s
²⁸⁰Rg	111	169	280.16447(80)#	3.6(+43-13) s
²⁸¹Rg	111	170	281.16537(100)#	1# min
²⁸²Rg	111	171	282.16749(95)#	4# min
²⁸³Rg	111	172	283.16842(84)#	10# min

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.

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.