Isotopes of gold

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Gold (Au) has one stable isotope, ¹⁹⁷Au, and 18 radioisotopes with ¹⁹⁵Au being the most stable with a half-life of 186 days.

Gold has been proposed as a salting material for nuclear weapons (cobalt is another, better-known salting material). A jacket of natural gold, irradiated by the intense high-energy neutron flux from an exploding thermonuclear weapon, would transmute into the radioactive isotope Au-198 with a halftime of 2.697 days and produce approximately .411 MeV of gamma radiation, significantly increasing the radioactivity of the weapon's fallout for several days. Such a weapon is not known to have ever been built, tested, or used.
Standard atomic mass: 196.966569(4) u

[edit] 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)
¹⁶⁹Au	79	90	168.99808(32)#	150# µs	1/2+#
¹⁷⁰Au	79	91	169.99612(22)#	310(50) µs [286(+50-40) µs]	(2-)
^170mAu	275(14) keV			630(60) µs [0.62(+6-5) ms]	(9+)
¹⁷¹Au	79	92	170.991879(28)	30(5) µs	(1/2+)
^171mAu	250(16) keV			1.014(19) ms	11/2-
¹⁷²Au	79	93	171.99004(17)#	4.7(11) ms	high
¹⁷³Au	79	94	172.986237(28)	25(1) ms	(1/2+)
^173mAu	214(23) keV			14.0(9) ms	(11/2-)
¹⁷⁴Au	79	95	173.98476(11)#	139(3) ms	low
^174mAu	360(70)# keV			171(29) ms	high
¹⁷⁵Au	79	96	174.98127(5)	100# ms	1/2+#
^175mAu	200(30)# keV			156(3) ms	11/2-#
¹⁷⁶Au	79	97	175.98010(11)#	1.08(17) s [0.84(+17-14) s]	(5-)
^176mAu	150(100)# keV			860(160) ms	(7+)
¹⁷⁷Au	79	98	176.976865(14)	1462(32) ms	(1/2+,3/2+)
^177mAu	216(26) keV			1.180(12) s	11/2-
¹⁷⁸Au	79	99	177.97603(6)	2.6(5) s
¹⁷⁹Au	79	100	178.973213(18)	7.1(3) s	5/2-#
^179mAu	99(16) keV				(11/2-)
¹⁸⁰Au	79	101	179.972521(23)	8.1(3) s
¹⁸¹Au	79	102	180.970079(21)	13.7(14) s	(3/2-)
¹⁸²Au	79	103	181.969618(22)	15.5(4) s	(2+)
¹⁸³Au	79	104	182.967593(11)	42.8(10) s	(5/2)-
^183m1Au	73.3(4) keV			>1 µs	(1/2)+
^183m2Au	230.6(6) keV			<1 µs	(11/2)-
¹⁸⁴Au	79	105	183.967452(24)	20.6(9) s	5+
^184mAu	68.46(1) keV			47.6(14) s	2+
¹⁸⁵Au	79	106	184.965789(28)	4.25(6) min	5/2-
^185mAu	100(100)# keV			6.8(3) min	1/2+#
¹⁸⁶Au	79	107	185.965953(23)	10.7(5) min	3-
^186mAu	227.77(7) keV			110(10) ns	2+
¹⁸⁷Au	79	108	186.964568(27)	8.4(3) min	1/2+
^187mAu	120.51(16) keV			2.3(1) s	9/2-
¹⁸⁸Au	79	109	187.965324(22)	8.84(6) min	1(-)
¹⁸⁹Au	79	110	188.963948(22)	28.7(3) min	1/2+
^189m1Au	247.23(16) keV			4.59(11) min	11/2-
^189m2Au	325.11(16) keV			190(15) ns	9/2-
^189m3Au	2554.7(12) keV			242(10) ns	31/2+
¹⁹⁰Au	79	111	189.964700(17)	42.8(10) min	1-
^190mAu	200(150)# keV			125(20) ms	11-#
¹⁹¹Au	79	112	190.96370(4)	3.18(8) h	3/2+
^191m1Au	266.2(5) keV			920(110) ms	(11/2-)
^191m2Au	2490(1) keV			>400 ns
¹⁹²Au	79	113	191.964813(17)	4.94(9) h	1-
^192m1Au	135.41(25) keV			29 ms	(5#)+
^192m2Au	431.6(5) keV			160(20) ms	(11-)
¹⁹³Au	79	114	192.964150(11)	17.65(15) h	3/2+
^193m1Au	290.19(3) keV			3.9(3) s	11/2-
^193m2Au	2486.5(6) keV			150(50) ns	(31/2+)
¹⁹⁴Au	79	115	193.965365(11)	38.02(10) h	1-
^194m1Au	107.4(5) keV			600(8) ms	(5+)
^194m2Au	475.8(6) keV			420(10) ms	(11-)
¹⁹⁵Au	79	116	194.9650346(14)	186.098(47) d	3/2+
^195mAu	318.58(4) keV			30.5(2) s	11/2-
¹⁹⁶Au	79	117	195.966570(3)	6.1669(6) d	2-
^196m1Au	84.660(20) keV			8.1(2) s	5+
^196m2Au	595.66(4) keV			9.6(1) h	12-
¹⁹⁷Au	79	118	196.9665687(6)	STABLE	3/2+	1.0000
^197mAu	409.15(8) keV			7.73(6) s	11/2-
¹⁹⁸Au	79	119	197.9682423(6)	2.69517(21) d	2-
^198m1Au	312.2200(20) keV			124(4) ns	5+
^198m2Au	811.7(15) keV			2.27(2) d	(12-)
¹⁹⁹Au	79	120	198.9687652(6)	3.139(7) d	3/2+
^199mAu	548.9368(21) keV			440(30) µs	(11/2)-
²⁰⁰Au	79	121	199.97073(5)	48.4(3) min	1(-)
^200mAu	970(70) keV			18.7(5) h	12-
²⁰¹Au	79	122	200.971657(3)	26(1) min	3/2+
²⁰²Au	79	123	201.97381(18)	28.8(19) s	(1-)
²⁰³Au	79	124	202.975155(3)	53(2) s	3/2+
²⁰⁴Au	79	125	203.97772(22)#	39.8(9) s	(2-)
²⁰⁵Au	79	126	204.97987(32)#	31(2) s	3/2+

[edit] 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.

[edit] 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.