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Gold (79Au) has one stable isotope, 197Au, and 36 radioisotopes, with 195Au being the most stable with a half-life of 186 days. Gold is currently considered the heaviest monoisotopic element (bismuth formerly held that distinction in the belief that the isotope, bismuth-209, was stable; however it is now known to be slightly radioactive).

Main isotopes of gold (79Au)
Iso­tope Decay
abun­dance half-life (t1/2) mode pro­duct
195Au syn 186.10 d ε 195Pt
196Au syn 6.183 d ε 196Pt
β 196Hg
197Au 100% stable
198Au syn 2.69517 d β 198Hg
199Au syn 3.169 d β 199Hg
Standard atomic weight Ar, standard(Au)
  • 196.966569(5)[1]

List of isotopesEdit

Nuclide
[n 1]
Z N Isotopic mass (u)
[n 2][n 3]
Half-life
[n 4]
Decay
mode

[n 5]
Daughter
isotope

[n 6][n 7]
Spin and
parity
[n 8][n 4]
Natural abundance (mole fraction)
Excitation energy[n 4] Normal proportion Range of variation
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 p 170Pt (1/2+)
α (rare) 167Ir
171mAu 250(16) keV 1.014(19) ms α (54%) 167Ir 11/2−
p (46%) 170Pt
172Au 79 93 171.99004(17)# 4.7(11) ms α (98%) 168Ir high
p (2%) 171Pt
173Au 79 94 172.986237(28) 25(1) ms α 169Ir (1/2+)
β+ (rare) 173Pt
173mAu 214(23) keV 14.0(9) ms α (96%) 169Ir (11/2−)
β+ (4%) 173Pt
174Au 79 95 173.98476(11)# 139(3) ms α 170Ir low
β+ (rare) 174Pt
174mAu 360(70)# keV 171(29) ms high
175Au 79 96 174.98127(5) 100# ms α (82%) 171Ir 1/2+#
β+ (18%) 175Pt
175mAu 200(30)# keV 156(3) ms α 171Ir 11/2−#
β+ 175Pt
176Au 79 97 175.98010(11)# 1.08(17) s
[0.84(+17−14) s]
α (60%) 172Ir (5−)
β+ (40%) 176Pt
176mAu 150(100)# keV 860(160) ms (7+)
177Au 79 98 176.976865(14) 1.462(32) s β+ (60%) 177Pt (1/2+, 3/2+)
α (40%) 173Ir
177mAu 216(26) keV 1.180(12) s 11/2−
178Au 79 99 177.97603(6) 2.6(5) s β+ (60%) 178Pt
α (40%) 174Ir
179Au 79 100 178.973213(18) 7.1(3) s β+ (78%) 179Pt 5/2−#
α (22%) 175Ir
179mAu 99(16) keV (11/2−)
180Au 79 101 179.972521(23) 8.1(3) s β+ (98.2%) 180Pt
α (1.8%) 176Ir
181Au 79 102 180.970079(21) 13.7(14) s β+ (97.3%) 181Pt (3/2−)
α (2.7%) 177Ir
182Au 79 103 181.969618(22) 15.5(4) s β+ (99.87%) 182Pt (2+)
α (.13%) 178Ir
183Au 79 104 182.967593(11) 42.8(10) s β+ (99.2%) 183Pt (5/2)−
α (.8%) 179Ir
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 β+ 184Pt 5+
184mAu 68.46(1) keV 47.6(14) s β+ (70%) 184Pt 2+
IT (30%) 184Au
α (.013%) 180Ir
185Au 79 106 184.965789(28) 4.25(6) min β+ (99.74%) 185Pt 5/2−
α (.26%) 181Ir
185mAu 100(100)# keV 6.8(3) min 1/2+#
186Au 79 107 185.965953(23) 10.7(5) min β+ (99.9992%) 186Pt 3−
α (8×10−4%) 182Ir
186mAu 227.77(7) keV 110(10) ns 2+
187Au 79 108 186.964568(27) 8.4(3) min β+ (99.997%) 187Pt 1/2+
α (.003%) 183Ir
187mAu 120.51(16) keV 2.3(1) s IT 187Au 9/2−
188Au 79 109 187.965324(22) 8.84(6) min β+ 188Pt 1(−)
189Au 79 110 188.963948(22) 28.7(3) min β+ (99.9997%) 189Pt 1/2+
α (3×10−4%) 185Ir
189m1Au 247.23(16) keV 4.59(11) min β+ 189Pt 11/2−
IT (rare) 189Au
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 β+ 190Pt 1−
α (10−6%) 186Ir
190mAu 200(150)# keV 125(20) ms IT 190Au 11−#
β+ (rare) 190Pt
191Au 79 112 190.96370(4) 3.18(8) h β+ 191Pt 3/2+
191m1Au 266.2(5) keV 920(110) ms IT 191Au (11/2−)
191m2Au 2490(1) keV >400 ns
192Au 79 113 191.964813(17) 4.94(9) h β+ 192Pt 1−
192m1Au 135.41(25) keV 29 ms IT 192Au (5#)+
192m2Au 431.6(5) keV 160(20) ms (11−)
193Au 79 114 192.964150(11) 17.65(15) h β+ (100%) 193Pt 3/2+
α (10−5%) 189Ir
193m1Au 290.19(3) keV 3.9(3) s IT (99.97%) 193Au 11/2−
β+ (.03%) 193Pt
193m2Au 2486.5(6) keV 150(50) ns (31/2+)
194Au 79 115 193.965365(11) 38.02(10) h β+ 194Pt 1−
194m1Au 107.4(5) keV 600(8) ms IT 194Au (5+)
194m2Au 475.8(6) keV 420(10) ms (11−)
195Au 79 116 194.9650346(14) 186.098(47) d EC 195Pt 3/2+
195mAu 318.58(4) keV 30.5(2) s IT 195Au 11/2−
196Au 79 117 195.966570(3) 6.1669(6) d β+ (93.05%) 196Pt 2−
β (6.95%) 196Hg
196m1Au 84.660(20) keV 8.1(2) s IT 196Au 5+
196m2Au 595.66(4) keV 9.6(1) h 12−
197Au[n 9] 79 118 196.9665687(6) Stable 3/2+ 1.0000
197mAu 409.15(8) keV 7.73(6) s IT 197Au 11/2−
198Au 79 119 197.9682423(6) 2.69517(21) d β 198Hg 2−
198m1Au 312.2200(20) keV 124(4) ns 5+
198m2Au 811.7(15) keV 2.27(2) d IT 198Au (12−)
199Au 79 120 198.9687652(6) 3.139(7) d β 199Hg 3/2+
199mAu 548.9368(21) keV 440(30) μs (11/2)−
200Au 79 121 199.97073(5) 48.4(3) min β 200Hg 1(−)
200mAu 970(70) keV 18.7(5) h β (82%) 200Hg 12−
IT (18%) 200Au
201Au 79 122 200.971657(3) 26(1) min β 201Hg 3/2+
201m1Au 594(5) keV 730(630) μs (11/2-)
201m2Au 1610(5) keV 5.6(2.4) μs (11/2-)
202Au 79 123 201.97381(18) 28.8(19) s β 202Hg (1−)
203Au 79 124 202.975155(3) 60(6) s β 203Hg 3/2+
203mAu 641(3) keV 140(44) μs IT 203Au 11/2−#
204Au 79 125 203.97772(22)# 38.3(1.3) s β 204Hg (2−)
204mAu 3816(1000)# keV 2.1(0.3) μs IT 204Au 16+#
205Au 79 126 204.97985(21)# 32.5(1.4) s β 205Hg 3/2+#
205m1Au 907(5) keV 6(2) s 11/2−#
205m2Au 2850(5) keV 163(5) ns 19/2+#
206Au 79 127 205.98474(32)# 47(11) s β 206Hg (5+, 6+)
  1. ^ mAu – Excited nuclear isomer.
  2. ^ ( ) – Uncertainty (1σ) is given in concise form in parentheses after the corresponding last digits.
  3. ^ # – Atomic mass marked #: value and uncertainty derived not from purely experimental data, but at least partly from trends from the Mass Surface (TMS).
  4. ^ a b c # – Values marked # are not purely derived from experimental data, but at least partly from trends of neighboring nuclides (TNN).
  5. ^ Modes of decay:
    EC: Electron capture
    IT: Isomeric transition


    p: Proton emission
  6. ^ Bold italics symbol as daughter – Daughter product is nearly stable.
  7. ^ Bold symbol as daughter – Daughter product is stable.
  8. ^ ( ) spin value – Indicates spin with weak assignment arguments.
  9. ^ Potential material for salted bombs

ReferencesEdit

  1. ^ Meija, Juris; et al. (2016). "Atomic weights of the elements 2013 (IUPAC Technical Report)". Pure and Applied Chemistry. 88 (3): 265–91. doi:10.1515/pac-2015-0305.