Gold Gold is a chemical element with the symbol Au (from la, aurum) and atomic number 79. This makes it one of the higher atomic number elements that occur naturally. It is a bright, slightly orange-yellow, dense, soft, malleable, and ductile me ...

(₇₉Au) has one stable

isotope Isotopes are two or more types of atoms that have the same atomic number (number of protons in their nuclei) and position in the periodic table (and hence belong to the same chemical element), and that differ in nucleon numbers (mass numb ...

, ¹⁹⁷Au, and 36

radioisotopes A radionuclide (radioactive nuclide, radioisotope or radioactive isotope) is a nuclide that has excess nuclear energy, making it unstable. This excess energy can be used in one of three ways: emitted from the nucleus as gamma radiation; transferr ...

, with ¹⁹⁵Au being the most stable with a

half-life Half-life (symbol ) is the time required for a quantity (of substance) to reduce to half of its initial value. The term is commonly used in nuclear physics to describe how quickly unstable atoms undergo radioactive decay or how long stable at ...

of 186 days. Gold is currently considered the heaviest

monoisotopic element A monoisotopic element is an element which has only a single stable isotope (nuclide). There are only 26 elements that have this property. A list is given in a following section. Stability is experimentally defined for chemical elements, as ther ...

Bismuth Bismuth is a chemical element with the symbol Bi and atomic number 83. It is a post-transition metal and one of the pnictogens, with chemical properties resembling its lighter group 15 siblings arsenic and antimony. Elemental bismuth occurs ...

formerly held that distinction until alpha-decay of the ²⁰⁹Bi isotope was observed. All isotopes of gold are either radioactive or, in the case of ¹⁹⁷Au,

observationally stable Stable nuclides are nuclides that are not radioactive and so (unlike radionuclides) do not spontaneously undergo radioactive decay. When such nuclides are referred to in relation to specific elements, they are usually termed stable isotopes. Th ...

, meaning that ¹⁹⁷Au is predicted to be radioactive but no actual decay has been observed.

List of isotopes

, - , ¹⁶⁹Au , style="text-align:right" , 79 , style="text-align:right" , 90 , 168.99808(32)# , 150# μs , , , 1/2+# , , , - , ¹⁷⁰Au , style="text-align:right" , 79 , style="text-align:right" , 91 , 169.99612(22)# , 310(50) μs
86(+50−40) μs, , , (2−) , , , - , style="text-indent:1em" , ^170mAu , colspan="3" style="text-indent:2em" , 275(14) keV , 630(60) μs
.62(+6−5) ms, , , (9+) , , , - , rowspan=2, ¹⁷¹Au , rowspan=2 style="text-align:right" , 79 , rowspan=2 style="text-align:right" , 92 , rowspan=2, 170.991879(28) , rowspan=2, 30(5) μs , p , ¹⁷⁰Pt , rowspan=2, (1/2+) , rowspan=2, , rowspan=2, , - , α (rare) , ¹⁶⁷Ir , - , rowspan=2 style="text-indent:1em" , ^171mAu , rowspan=2 colspan="3" style="text-indent:2em" , 250(16) keV , rowspan=2, 1.014(19) ms , α (54%) , ¹⁶⁷Ir , rowspan=2, 11/2− , rowspan=2, , rowspan=2, , - , p (46%) , ¹⁷⁰Pt , - , rowspan=2, ¹⁷²Au , rowspan=2 style="text-align:right" , 79 , rowspan=2 style="text-align:right" , 93 , rowspan=2, 171.99004(17)# , rowspan=2, 4.7(11) ms , α (98%) , ¹⁶⁸Ir , rowspan=2, high , rowspan=2, , rowspan=2, , - , p (2%) , ¹⁷¹Pt , - , rowspan=2, ¹⁷³Au , rowspan=2 style="text-align:right" , 79 , rowspan=2 style="text-align:right" , 94 , rowspan=2, 172.986237(28) , rowspan=2, 25(1) ms , α , ¹⁶⁹Ir , rowspan=2, (1/2+) , rowspan=2, , rowspan=2, , - , β⁺ (rare) , ¹⁷³Pt , - , rowspan=2 style="text-indent:1em" , ^173mAu , rowspan=2 colspan="3" style="text-indent:2em" , 214(23) keV , rowspan=2, 14.0(9) ms , α (96%) , ¹⁶⁹Ir , rowspan=2, (11/2−) , rowspan=2, , rowspan=2, , - , β⁺ (4%) , ¹⁷³Pt , - , rowspan=2, ¹⁷⁴Au , rowspan=2 style="text-align:right" , 79 , rowspan=2 style="text-align:right" , 95 , rowspan=2, 173.98476(11)# , rowspan=2, 139(3) ms , α , ¹⁷⁰Ir , rowspan=2, low , rowspan=2, , rowspan=2, , - , β⁺ (rare) , ¹⁷⁴Pt , - , style="text-indent:1em" , ^174mAu , colspan="3" style="text-indent:2em" , 360(70)# keV , 171(29) ms , , , high , , , - , rowspan=2, ¹⁷⁵Au , rowspan=2 style="text-align:right" , 79 , rowspan=2 style="text-align:right" , 96 , rowspan=2, 174.98127(5) , rowspan=2, 100# ms , α (82%) , ¹⁷¹Ir , rowspan=2, 1/2+# , rowspan=2, , rowspan=2, , - , β⁺ (18%) , ¹⁷⁵Pt , - , rowspan=2 style="text-indent:1em" , ^175mAu , rowspan=2 colspan="3" style="text-indent:2em" , 200(30)# keV , rowspan=2, 156(3) ms , α , ¹⁷¹Ir , rowspan=2, 11/2−# , rowspan=2, , rowspan=2, , - , β⁺ , ¹⁷⁵Pt , - , rowspan=2, ¹⁷⁶Au , rowspan=2 style="text-align:right" , 79 , rowspan=2 style="text-align:right" , 97 , rowspan=2, 175.98010(11)# , rowspan=2, 1.08(17) s
.84(+17−14) s, α (60%) , ¹⁷²Ir , rowspan=2, (5−) , rowspan=2, , rowspan=2, , - , β⁺ (40%) , ¹⁷⁶Pt , - , style="text-indent:1em" , ^176mAu , colspan="3" style="text-indent:2em" , 150(100)# keV , 860(160) ms , , , (7+) , , , - , rowspan=2, ¹⁷⁷Au , rowspan=2 style="text-align:right" , 79 , rowspan=2 style="text-align:right" , 98 , rowspan=2, 176.976865(14) , rowspan=2, 1.462(32) s , β⁺ (60%) , ¹⁷⁷Pt , rowspan=2, (1/2+, 3/2+) , rowspan=2, , rowspan=2, , - , α (40%) , ¹⁷³Ir , - , style="text-indent:1em" , ^177mAu , colspan="3" style="text-indent:2em" , 216(26) keV , 1.180(12) s , , , 11/2− , , , - , rowspan=2, ¹⁷⁸Au , rowspan=2 style="text-align:right" , 79 , rowspan=2 style="text-align:right" , 99 , rowspan=2, 177.97603(6) , rowspan=2, 2.6(5) s , β⁺ (60%) , ¹⁷⁸Pt , rowspan=2, , rowspan=2, , rowspan=2, , - , α (40%) , ¹⁷⁴Ir , - , rowspan=2, ¹⁷⁹Au , rowspan=2 style="text-align:right" , 79 , rowspan=2 style="text-align:right" , 100 , rowspan=2, 178.973213(18) , rowspan=2, 7.1(3) s , β⁺ (78%) , ¹⁷⁹Pt , rowspan=2, 5/2−# , rowspan=2, , rowspan=2, , - , α (22%) , ¹⁷⁵Ir , - , style="text-indent:1em" , ^179mAu , colspan="3" style="text-indent:2em" , 99(16) keV , , , , (11/2−) , , , - , rowspan=2, ¹⁸⁰Au , rowspan=2 style="text-align:right" , 79 , rowspan=2 style="text-align:right" , 101 , rowspan=2, 179.972521(23) , rowspan=2, 8.1(3) s , β⁺ (98.2%) , ¹⁸⁰Pt , rowspan=2, , rowspan=2, , rowspan=2, , - , α (1.8%) , ¹⁷⁶Ir , - , rowspan=2, ¹⁸¹Au , rowspan=2 style="text-align:right" , 79 , rowspan=2 style="text-align:right" , 102 , rowspan=2, 180.970079(21) , rowspan=2, 13.7(14) s , β⁺ (97.3%) , ¹⁸¹Pt , rowspan=2, (3/2−) , rowspan=2, , rowspan=2, , - , α (2.7%) , ¹⁷⁷Ir , - , rowspan=2, ¹⁸²Au , rowspan=2 style="text-align:right" , 79 , rowspan=2 style="text-align:right" , 103 , rowspan=2, 181.969618(22) , rowspan=2, 15.5(4) s , β⁺ (99.87%) , ¹⁸²Pt , rowspan=2, (2+) , rowspan=2, , rowspan=2, , - , α (.13%) , ¹⁷⁸Ir , - , rowspan=2, ¹⁸³Au , rowspan=2 style="text-align:right" , 79 , rowspan=2 style="text-align:right" , 104 , rowspan=2, 182.967593(11) , rowspan=2, 42.8(10) s , β⁺ (99.2%) , ¹⁸³Pt , rowspan=2, (5/2)− , rowspan=2, , rowspan=2, , - , α (.8%) , ¹⁷⁹Ir , - , style="text-indent:1em" , ^183m1Au , colspan="3" style="text-indent:2em" , 73.3(4) keV , >1 μs , , , (1/2)+ , , , - , style="text-indent:1em" , ^183m2Au , colspan="3" style="text-indent:2em" , 230.6(6) keV , <1 μs , , , (11/2)− , , , - , ¹⁸⁴Au , style="text-align:right" , 79 , style="text-align:right" , 105 , 183.967452(24) , 20.6(9) s , β⁺ , ¹⁸⁴Pt , 5+ , , , - , rowspan=3 style="text-indent:1em" , ^184mAu , rowspan=3 colspan="3" style="text-indent:2em" , 68.46(1) keV , rowspan=3, 47.6(14) s , β⁺ (70%) , ¹⁸⁴Pt , rowspan=3, 2+ , rowspan=3, , rowspan=3, , - , IT (30%) , ¹⁸⁴Au , - , α (.013%) , ¹⁸⁰Ir , - , rowspan=2, ¹⁸⁵Au , rowspan=2 style="text-align:right" , 79 , rowspan=2 style="text-align:right" , 106 , rowspan=2, 184.965789(28) , rowspan=2, 4.25(6) min , β⁺ (99.74%) , ¹⁸⁵Pt , rowspan=2, 5/2− , rowspan=2, , rowspan=2, , - , α (.26%) , ¹⁸¹Ir , - , style="text-indent:1em" , ^185mAu , colspan="3" style="text-indent:2em" , 100(100)# keV , 6.8(3) min , , , 1/2+# , , , - , rowspan=2, ¹⁸⁶Au , rowspan=2 style="text-align:right" , 79 , rowspan=2 style="text-align:right" , 107 , rowspan=2, 185.965953(23) , rowspan=2, 10.7(5) min , β⁺ (99.9992%) , ¹⁸⁶Pt , rowspan=2, 3− , rowspan=2, , rowspan=2, , - , α (8×10⁻⁴%) , ¹⁸²Ir , - , style="text-indent:1em" , ^186mAu , colspan="3" style="text-indent:2em" , 227.77(7) keV , 110(10) ns , , , 2+ , , , - , rowspan=2, ¹⁸⁷Au , rowspan=2 style="text-align:right" , 79 , rowspan=2 style="text-align:right" , 108 , rowspan=2, 186.964568(27) , rowspan=2, 8.4(3) min , β⁺ (99.997%) , ¹⁸⁷Pt , rowspan=2, 1/2+ , rowspan=2, , rowspan=2, , - , α (.003%) , ¹⁸³Ir , - , style="text-indent:1em" , ^187mAu , colspan="3" style="text-indent:2em" , 120.51(16) keV , 2.3(1) s , IT , ¹⁸⁷Au , 9/2− , , , - , ¹⁸⁸Au , style="text-align:right" , 79 , style="text-align:right" , 109 , 187.965324(22) , 8.84(6) min , β⁺ , ¹⁸⁸Pt , 1(−) , , , - , rowspan=2, ¹⁸⁹Au , rowspan=2 style="text-align:right" , 79 , rowspan=2 style="text-align:right" , 110 , rowspan=2, 188.963948(22) , rowspan=2, 28.7(3) min , β⁺ (99.9997%) , ¹⁸⁹Pt , rowspan=2, 1/2+ , rowspan=2, , rowspan=2, , - , α (3×10⁻⁴%) , ¹⁸⁵Ir , - , rowspan=2 style="text-indent:1em" , ^189m1Au , rowspan=2 colspan="3" style="text-indent:2em" , 247.23(16) keV , rowspan=2, 4.59(11) min , β⁺ , ¹⁸⁹Pt , rowspan=2, 11/2− , rowspan=2, , rowspan=2, , - , IT (rare) , ¹⁸⁹Au , - , style="text-indent:1em" , ^189m2Au , colspan="3" style="text-indent:2em" , 325.11(16) keV , 190(15) ns , , , 9/2− , , , - , style="text-indent:1em" , ^189m3Au , colspan="3" style="text-indent:2em" , 2554.7(12) keV , 242(10) ns , , , 31/2+ , , , - , rowspan=2, ¹⁹⁰Au , rowspan=2 style="text-align:right" , 79 , rowspan=2 style="text-align:right" , 111 , rowspan=2, 189.964700(17) , rowspan=2, 42.8(10) min , β⁺ , ''¹⁹⁰Pt'' , rowspan=2, 1− , rowspan=2, , rowspan=2, , - , α (10⁻⁶%) , ¹⁸⁶Ir , - , rowspan=2 style="text-indent:1em" , ^190mAu , rowspan=2 colspan="3" style="text-indent:2em" , 200(150)# keV , rowspan=2, 125(20) ms , IT , ¹⁹⁰Au , rowspan=2, 11−# , rowspan=2, , rowspan=2, , - , β⁺ (rare) , ''¹⁹⁰Pt'' , - , ¹⁹¹Au , style="text-align:right" , 79 , style="text-align:right" , 112 , 190.96370(4) , 3.18(8) h , β⁺ , ¹⁹¹Pt , 3/2+ , , , - , style="text-indent:1em" , ^191m1Au , colspan="3" style="text-indent:2em" , 266.2(5) keV , 920(110) ms , IT , ¹⁹¹Au , (11/2−) , , , - , style="text-indent:1em" , ^191m2Au , colspan="3" style="text-indent:2em" , 2490(1) keV , >400 ns , , , , , , - , ¹⁹²Au , style="text-align:right" , 79 , style="text-align:right" , 113 , 191.964813(17) , 4.94(9) h , β⁺ , ¹⁹²Pt , 1− , , , - , style="text-indent:1em" , ^192m1Au , colspan="3" style="text-indent:2em" , 135.41(25) keV , 29 ms , IT , ¹⁹²Au , (5#)+ , , , - , style="text-indent:1em" , ^192m2Au , colspan="3" style="text-indent:2em" , 431.6(5) keV , 160(20) ms , , , (11−) , , , - , rowspan=2, ¹⁹³Au , rowspan=2 style="text-align:right" , 79 , rowspan=2 style="text-align:right" , 114 , rowspan=2, 192.964150(11) , rowspan=2, 17.65(15) h , β⁺ (100%) , ¹⁹³Pt , rowspan=2, 3/2+ , rowspan=2, , rowspan=2, , - , α (10⁻⁵%) , ¹⁸⁹Ir , - , rowspan=2 style="text-indent:1em" , ^193m1Au , rowspan=2 colspan="3" style="text-indent:2em" , 290.19(3) keV , rowspan=2, 3.9(3) s , IT (99.97%) , ¹⁹³Au , rowspan=2, 11/2− , rowspan=2, , rowspan=2, , - , β⁺ (.03%) , ¹⁹³Pt , - , style="text-indent:1em" , ^193m2Au , colspan="3" style="text-indent:2em" , 2486.5(6) keV , 150(50) ns , , , (31/2+) , , , - , ¹⁹⁴Au , style="text-align:right" , 79 , style="text-align:right" , 115 , 193.965365(11) , 38.02(10) h , β⁺ , ¹⁹⁴Pt , 1− , , , - , style="text-indent:1em" , ^194m1Au , colspan="3" style="text-indent:2em" , 107.4(5) keV , 600(8) ms , IT , ¹⁹⁴Au , (5+) , , , - , style="text-indent:1em" , ^194m2Au , colspan="3" style="text-indent:2em" , 475.8(6) keV , 420(10) ms , , , (11−) , , , - , ¹⁹⁵Au , style="text-align:right" , 79 , style="text-align:right" , 116 , 194.9650346(14) , 186.098(47) d , EC , ¹⁹⁵Pt , 3/2+ , , , - , style="text-indent:1em" , ^195mAu , colspan="3" style="text-indent:2em" , 318.58(4) keV , 30.5(2) s , IT , ¹⁹⁵Au , 11/2− , , , - , rowspan=2, ¹⁹⁶Au , rowspan=2 style="text-align:right" , 79 , rowspan=2 style="text-align:right" , 117 , rowspan=2, 195.966570(3) , rowspan=2, 6.1669(6) d , EC (93.05%) , ¹⁹⁶Pt , rowspan=2, 2− , rowspan=2, , rowspan=2, , - , β⁻ (6.95%) , ¹⁹⁶Hg , - , style="text-indent:1em" , ^196m1Au , colspan="3" style="text-indent:2em" , 84.660(20) keV , 8.1(2) s , IT , ¹⁹⁶Au , 5+ , , , - , style="text-indent:1em" , ^196m2Au , colspan="3" style="text-indent:2em" , 595.66(4) keV , 9.6(1) h , , , 12− , , , - , ¹⁹⁷AuPotential material for salted bombs , style="text-align:right" , 79 , style="text-align:right" , 118 , 196.9665687(6) , colspan=3 align=center,

Observationally Stable Stable nuclides are nuclides that are not radioactive and so (unlike radionuclides) do not spontaneously undergo radioactive decay. When such nuclides are referred to in relation to specific elements, they are usually termed stable isotopes. Th ...

Believed to undergo α decay to ¹⁹³Ir , 3/2+ , 1.0000 , , - , style="text-indent:1em" , ^197mAu , colspan="3" style="text-indent:2em" , 409.15(8) keV , 7.73(6) s , IT , ¹⁹⁷Au , 11/2− , , , - , ¹⁹⁸Au , style="text-align:right" , 79 , style="text-align:right" , 119 , 197.9682423(6) , 2.69517(21) d , β⁻ , ¹⁹⁸Hg , 2− , , , - , style="text-indent:1em" , ^198m1Au , colspan="3" style="text-indent:2em" , 312.2200(20) keV , 124(4) ns , , , 5+ , , , - , style="text-indent:1em" , ^198m2Au , colspan="3" style="text-indent:2em" , 811.7(15) keV , 2.27(2) d , IT , ¹⁹⁸Au , (12−) , , , - , ¹⁹⁹Au , style="text-align:right" , 79 , style="text-align:right" , 120 , 198.9687652(6) , 3.139(7) d , β⁻ , ¹⁹⁹Hg , 3/2+ , , , - , style="text-indent:1em" , ^199mAu , colspan="3" style="text-indent:2em" , 548.9368(21) keV , 440(30) μs , , , (11/2)− , , , - , ²⁰⁰Au , style="text-align:right" , 79 , style="text-align:right" , 121 , 199.97073(5) , 48.4(3) min , β⁻ , ²⁰⁰Hg , 1(−) , , , - , rowspan=2 style="text-indent:1em" , ^200mAu , rowspan=2 colspan="3" style="text-indent:2em" , 970(70) keV , rowspan=2, 18.7(5) h , β⁻ (82%) , ²⁰⁰Hg , rowspan=2, 12− , rowspan=2, , rowspan=2, , - , IT (18%) , ²⁰⁰Au , - , ²⁰¹Au , style="text-align:right" , 79 , style="text-align:right" , 122 , 200.971657(3) , 26(1) min , β⁻ , ²⁰¹Hg , 3/2+ , , , - , style="text-indent:1em" , ^201m1Au , colspan="3" style="text-indent:2em" , 594(5) keV , 730(630) μs , , , (11/2-) , , , - , style="text-indent:1em" , ^201m2Au , colspan="3" style="text-indent:2em" , 1610(5) keV , 5.6(2.4) μs , , , (11/2-) , , , - , ²⁰²Au , style="text-align:right" , 79 , style="text-align:right" , 123 , 201.97381(18) , 28.8(19) s , β⁻ , ²⁰²Hg , (1−) , , , - , ²⁰³Au , style="text-align:right" , 79 , style="text-align:right" , 124 , 202.975155(3) , 60(6) s , β⁻ , ²⁰³Hg , 3/2+ , , , - , style="text-indent:1em" , ^203mAu , colspan="3" style="text-indent:2em" , 641(3) keV , 140(44) μs , IT , ²⁰³Au , 11/2−# , , , - , ²⁰⁴Au , style="text-align:right" , 79 , style="text-align:right" , 125 , 203.97772(22)# , 38.3(1.3) s , β⁻ , ²⁰⁴Hg , (2−) , , , - , style="text-indent:1em" , ^204mAu , colspan="3" style="text-indent:2em" , 3816(1000)# keV , 2.1(0.3) μs , IT , ²⁰⁴Au , 16+# , , , - , ²⁰⁵Au , style="text-align:right" , 79 , style="text-align:right" , 126 , 204.97985(21)# , 32.5(1.4) s , β⁻ , ²⁰⁵Hg , 3/2+# , , , - , style="text-indent:1em" , ^205m1Au , colspan="3" style="text-indent:2em" , 907(5) keV , 6(2) s , , , 11/2−# , , , - , style="text-indent:1em" , ^205m2Au , colspan="3" style="text-indent:2em" , 2850(5) keV , 163(5) ns , , , 19/2+# , , , - , ²⁰⁶Au , style="text-align:right" , 79 , style="text-align:right" , 127 , 205.98474(32)# , 47(11) s , β⁻ , ²⁰⁶Hg , (5+, 6+) , ,

References

* Isotope masses from: ** * Isotopic compositions and standard atomic masses from: ** ** * Half-life, spin, and isomer data selected from the following sources. ** ** ** {{Navbox element isotopes Gold