| ||||||||||||||||||||||||||||||||||||||
Standard atomic weight Ar°(Au) | ||||||||||||||||||||||||||||||||||||||
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Gold (79Au) has one stable isotope, 197Au, and 40 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 until alpha-decay of the 209Bi isotope was observed. All isotopes of gold are either radioactive or, in the case of 197Au, observationally stable, meaning that 197Au is predicted to be radioactive but no actual decay has been observed. [4]
Nuclide [n 1] | Z | N | Isotopic mass (Da) [5] [n 2] [n 3] | Half-life [1] [n 4] | Decay mode [1] [n 5] | Daughter isotope [n 6] [n 7] | Spin and parity [1] [n 8] [n 4] | Isotopic abundance | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Excitation energy [n 4] | |||||||||||||||||||
170Au [6] | 79 | 91 | 169.99602(22)# | 286+50 −40 μs | p (89%) | 169Pt | (2)− | ||||||||||||
α (11%) | 166Ir | ||||||||||||||||||
170mAu [6] | 282(10) keV | 617+50 −40 μs | p (58%) | 169Pt | (9)+ | ||||||||||||||
α (42%) | 166mIr | ||||||||||||||||||
171Au [6] | 79 | 92 | 170.991882(22) | 22+3 −2 μs | p | 170Pt | 1/2+ | ||||||||||||
α? | 167Ir | ||||||||||||||||||
171mAu [6] | 258(13) keV | 1.09(3) ms | α (66%) | 167mIr | 11/2− | ||||||||||||||
p (34%) | 170Pt | ||||||||||||||||||
172Au | 79 | 93 | 171.99000(6) | 28(4) ms | α (98%) | 168Ir | (2)− | ||||||||||||
p (2%) | 171Pt | ||||||||||||||||||
β+ | 172Pt | ||||||||||||||||||
172mAu [n 9] | 160(250) keV | 11.0(10) ms | α | 168Ir | (9,10)+ | ||||||||||||||
p? | 171Pt | ||||||||||||||||||
173Au | 79 | 94 | 172.986224(24) | 25.5(8) ms | α (86%) | 169Ir | (1/2+) | ||||||||||||
β+ (14%) | 173Pt | ||||||||||||||||||
173mAu | 214(21) keV | 12.2(1) ms | α (89%) | 169Ir | (11/2−) | ||||||||||||||
β+ (11%) | 173Pt | ||||||||||||||||||
174Au | 79 | 95 | 173.98491(11)# | 139(3) ms | α (90%) | 170Ir | (3−) | ||||||||||||
β+ (10%) | 174Pt | ||||||||||||||||||
174mAu | 130(50)# keV | 162(2) ms | α? | 170Ir | (9+) | ||||||||||||||
β+? | 174Pt | ||||||||||||||||||
175Au | 79 | 96 | 174.98132(4) | 200(3) ms | α (88%) | 171Ir | 1/2+ | ||||||||||||
β+ (12%) | 175Pt | ||||||||||||||||||
175mAu | 164(11)# keV | 136(1) ms | α (75%) | 171Ir | (11/2−) | ||||||||||||||
β+ (25%) | 175Pt | ||||||||||||||||||
176Au | 79 | 97 | 175.98012(4) | 1.05(1) s | α (75%) | 172Ir | (3−,4−) | ||||||||||||
β+ (25%) | 176Pt | ||||||||||||||||||
176mAu [n 9] | 139(13) keV | 1.36(2) s | α? | 172Ir | (8+,9+) | ||||||||||||||
β+? | 176Pt | ||||||||||||||||||
177Au | 79 | 98 | 176.976870(11) | 1.501(20) s | β+ (60%) | 177Pt | 1/2+ | ||||||||||||
α (40%) | 173Ir | ||||||||||||||||||
177mAu | 190(7) keV | 1.193(13) s | α (60%) | 173Ir | 11/2− | ||||||||||||||
β+ (40%) | 177Pt | ||||||||||||||||||
178Au | 79 | 99 | 177.976057(11) | 3.4(5) s | β+ (84%) | 178Pt | (2+,3−) | ||||||||||||
α (16%) | 174Ir | ||||||||||||||||||
178m1Au | 50.3(2) keV | 300(10) ns | IT | 178Au | (4−,5+) | ||||||||||||||
178m2Au | 186(14) keV | 2.7(5) s | β+ (82%) | 178Pt | (7+,8−) | ||||||||||||||
α (18%) | 174Ir | ||||||||||||||||||
178m3Au | 243(14) keV | 390(10) ns | IT | 178Au | (5+,6) | ||||||||||||||
179Au | 79 | 100 | 178.973174(13) | 7.1(3) s | β+ (78.0%) | 179Pt | 1/2+ | ||||||||||||
α (22.0%) | 175Ir | ||||||||||||||||||
179mAu | 89.5(3) keV | 327(5) ns | IT | 179Au | (3/2−) | ||||||||||||||
180Au | 79 | 101 | 179.9724898(51) | 7.9(3) s | β+ (99.42%) | 180Pt | (1+) | ||||||||||||
α (0.58%) | 176Ir | ||||||||||||||||||
181Au | 79 | 102 | 180.970079(21) | 13.7(14) s | β+ (97.3%) | 181Pt | (5/2−) | ||||||||||||
α (2.7%) | 177Ir | ||||||||||||||||||
182Au | 79 | 103 | 181.969614(20) | 15.5(4) s | β+ (99.87%) | 182Pt | (2+) | ||||||||||||
α (0.13%) | 178Ir | ||||||||||||||||||
183Au | 79 | 104 | 182.967588(10) | 42.8(10) s | β+ (99.45%) | 183Pt | 5/2− | ||||||||||||
α (0.55%) | 179Ir | ||||||||||||||||||
183mAu | 73.10(1) keV | >1 μs | IT | 183Au | (1/2)+ | ||||||||||||||
184Au | 79 | 105 | 183.967452(24) | 20.6(9) s | β+ (99.99%) | 184Pt | 5+ | ||||||||||||
α (0.013%) | 180Ir | ||||||||||||||||||
184mAu | 68.46(4) keV | 47.6(14) s | β+ (70%) | 184Pt | 2+ | ||||||||||||||
IT (30%) | 184Au | ||||||||||||||||||
α (0.013%) | 180Ir | ||||||||||||||||||
185Au | 79 | 106 | 184.9657989(28) | 4.25(6) min | β+ (99.74%) | 185Pt | 5/2− | ||||||||||||
α (0.26%) | 181Ir | ||||||||||||||||||
185mAu [n 9] | 50(50)# keV | 6.8(3) min | β+ | 185Pt | 1/2+# | ||||||||||||||
IT? | 185Au | ||||||||||||||||||
186Au | 79 | 107 | 185.965953(23) | 10.7(5) min | β+ | 186Pt | 3− | ||||||||||||
α (8×10−4%) | 182Ir | ||||||||||||||||||
186mAu | 227.77(7) keV | 110(10) ns | IT | 186Au | 2+ | ||||||||||||||
187Au | 79 | 108 | 186.964542(24) | 8.3(2) min | β+ | 187Pt | 1/2+ | ||||||||||||
α? | 183Ir | ||||||||||||||||||
187mAu | 120.33(14) keV | 2.3(1) s | IT | 187Au | 9/2− | ||||||||||||||
188Au | 79 | 109 | 187.9652480(29) | 8.84(6) min | β+ | 188Pt | 1− | ||||||||||||
189Au | 79 | 110 | 188.963948(22) | 28.7(4) min | β+ | 189Pt | 1/2+ | ||||||||||||
α? (<3×10−5%) | 185Ir | ||||||||||||||||||
189m1Au | 247.25(16) keV | 4.59(11) min | β+ | 189Pt | 11/2− | ||||||||||||||
IT? | 189Au | ||||||||||||||||||
189m2Au | 325.12(16) keV | 190(15) ns | IT | 189Au | 9/2− | ||||||||||||||
189m3Au | 2554.8(8) keV | 242(10) ns | IT | 189Au | 31/2+ | ||||||||||||||
190Au | 79 | 111 | 189.964752(4) | 42.8(10) min | β+ | 190Pt | 1− | ||||||||||||
α? (<10−6%) | 186Ir | ||||||||||||||||||
190mAu [n 9] | 200(150)# keV | 125(20) ms | IT | 190Au | 11−# | ||||||||||||||
β+? | 190Pt | ||||||||||||||||||
191Au | 79 | 112 | 190.963716(5) | 3.18(8) h | β+ | 191Pt | 3/2+ | ||||||||||||
191m1Au | 266.2(7) keV | 920(110) ms | IT | 191Au | 11/2− | ||||||||||||||
191m2Au | 2489.6(9) keV | 402(20) ns | IT | 191Au | 31/2+ | ||||||||||||||
192Au | 79 | 113 | 191.964818(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 | IT | 192Au | 11− | ||||||||||||||
193Au | 79 | 114 | 192.964138(9) | 17.65(15) h | β+ [n 10] | 193Pt | 3/2+ | ||||||||||||
193m1Au | 290.20(4) keV | 3.9(3) s | IT (99.97%) | 193Au | 11/2− | ||||||||||||||
β+ (0.03%) | 193Pt | ||||||||||||||||||
193m2Au | 2486.7(6) keV | 150(50) ns | IT | 193Au | 31/2+ | ||||||||||||||
194Au | 79 | 115 | 193.9654191(23) | 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 | IT | 194Au | 11− | ||||||||||||||
195Au | 79 | 116 | 194.9650378(12) | 186.01(6) d | EC | 195Pt | 3/2+ | ||||||||||||
195m1Au | 318.58(4) keV | 30.5(2) s | IT | 195Au | 11/2− | ||||||||||||||
195m2Au | 2501(20)# keV | 12.89(21) μs | IT | 195Au | 31/2(−) | ||||||||||||||
196Au | 79 | 117 | 195.966571(3) | 6.165(11) d | β+ (93.0%) | 196Pt | 2− | ||||||||||||
β− (7.0%) | 196Hg | ||||||||||||||||||
196m1Au | 84.656(20) keV | 8.1(2) s | IT | 196Au | 5+ | ||||||||||||||
196m2Au | 595.66(4) keV | 9.603(22) h | IT | 196Au | 12− | ||||||||||||||
197Au [n 11] | 79 | 118 | 196.9665701(6) | Observationally Stable [n 12] | 3/2+ | 1.0000 | |||||||||||||
197m1Au | 409.15(8) keV | 7.73(6) s | IT | 197Au | 11/2− | ||||||||||||||
197m2Au | 2532.5(10) keV | 150(5) ns | IT | 197Au | 27/2+# | ||||||||||||||
198Au | 79 | 119 | 197.9682437(6) | 2.69464(14) d | β− | 198Hg | 2− | ||||||||||||
198m1Au | 312.2227(20) keV | 124(4) ns | IT | 198Au | 5+ | ||||||||||||||
198m2Au | 811.9(15) keV | 2.272(16) d | IT | 198Au | 12− | ||||||||||||||
199Au | 79 | 120 | 198.9687666(6) | 3.139(7) d | β− | 199Hg | 3/2+ | ||||||||||||
199mAu | 548.9405(21) keV | 440(30) μs | IT | 199Au | 11/2− | ||||||||||||||
200Au | 79 | 121 | 199.970757(29) | 48.4(3) min | β− | 200Hg | (1−) | ||||||||||||
200mAu | 1010(40) keV | 18.7(5) h | β− (84%) | 200Hg | 12− | ||||||||||||||
IT (16%) | 200Au | ||||||||||||||||||
201Au | 79 | 122 | 200.971658(3) | 26.0(8) min | β− | 201Hg | 3/2+ | ||||||||||||
201m1Au | 594(5) keV | 730(630) μs | IT | 201Au | 11/2- | ||||||||||||||
201m2Au | 1610(5) keV | 5.6(24) μs | IT | 201Au | 19/2+# | ||||||||||||||
202Au | 79 | 123 | 201.973856(25) | 28.4(12) s | β− | 202Hg | (1−) | ||||||||||||
203Au | 79 | 124 | 202.9751545(33) | 60(6) s | β− | 203Hg | 3/2+ | ||||||||||||
203mAu | 641(3) keV | 140(44) μs | IT | 203Au | 11/2−# | ||||||||||||||
204Au | 79 | 125 | 203.97811(22)# | 38.3(13) s | β− | 204Hg | (2−) | ||||||||||||
204mAu | 3816(500)# keV | 2.1(3) μs | IT | 204Au | 16+# | ||||||||||||||
205Au | 79 | 126 | 204.98006(22)# | 32.0(14) s | β− | 205Hg | 3/2+# | ||||||||||||
205m1Au | 907(5) keV | 6(2) s | IT? | 205Au | 11/2−# | ||||||||||||||
β−? | 205Hg | ||||||||||||||||||
205m2Au | 2849.7(4) keV | 163(5) ns | IT | 205Au | 19/2+# | ||||||||||||||
206Au | 79 | 127 | 205.98477(32)# | 47(11) s | β− | 206Hg | 6+# | ||||||||||||
207Au | 79 | 128 | 206.98858(32)# | 3# s [>300 ns] | β−? | 207Hg | 3/2+# | ||||||||||||
β−, n? | 206Hg | ||||||||||||||||||
208Au | 79 | 129 | 207.99366(32)# | 20# s [>300 ns] | β−? | 208Hg | 6+# | ||||||||||||
β−, n? | 207Hg | ||||||||||||||||||
209Au | 79 | 130 | 208.99761(43)# | 1# s [>300 ns] | β−? | 209Hg | 3/2+# | ||||||||||||
β−, n? | 210Hg | ||||||||||||||||||
210Au | 79 | 131 | 210.00288(43)# | 10# s [>300 ns] | β−? | 210Hg | 6+# | ||||||||||||
β−, n? | 209Hg | ||||||||||||||||||
This table header & footer: |
EC: | Electron capture |
IT: | Isomeric transition |
p: | Proton emission |
Bismuth (83Bi) has 41 known isotopes, ranging from 184Bi to 224Bi. Bismuth has no stable isotopes, but does have one very long-lived isotope; thus, the standard atomic weight can be given as 208.98040(1). Although bismuth-209 is now known to be radioactive, it has classically been considered to be a stable isotope because it has a half-life of approximately 2.01×1019 years, which is more than a billion times the age of the universe. Besides 209Bi, the most stable bismuth radioisotopes are 210mBi with a half-life of 3.04 million years, 208Bi with a half-life of 368,000 years and 207Bi, with a half-life of 32.9 years, none of which occurs in nature. All other isotopes have half-lives under 1 year, most under a day. Of naturally occurring radioisotopes, the most stable is radiogenic 210Bi with a half-life of 5.012 days. 210mBi is unusual for being a nuclear isomer with a half-life multiple orders of magnitude longer than that of the ground state.
Thallium (81Tl) has 41 isotopes with atomic masses that range from 176 to 216. 203Tl and 205Tl are the only stable isotopes and 204Tl is the most stable radioisotope with a half-life of 3.78 years. 207Tl, with a half-life of 4.77 minutes, has the longest half-life of naturally occurring Tl radioisotopes. All isotopes of thallium are either radioactive or observationally stable, meaning that they are predicted to be radioactive but no actual decay has been observed.
There are seven stable isotopes of mercury (80Hg) with 202Hg being the most abundant (29.86%). The longest-lived radioisotopes are 194Hg with a half-life of 444 years, and 203Hg with a half-life of 46.612 days. Most of the remaining 40 radioisotopes have half-lives that are less than a day. 199Hg and 201Hg are the most often studied NMR-active nuclei, having spin quantum numbers of 1/2 and 3/2 respectively. All isotopes of mercury are either radioactive or observationally stable, meaning that they are predicted to be radioactive but no actual decay has been observed. These isotopes are predicted to undergo either alpha decay or double beta decay.
Naturally occurring platinum (78Pt) consists of five stable isotopes (192Pt, 194Pt, 195Pt, 196Pt, 198Pt) and one very long-lived (half-life 4.83×1011 years) radioisotope (190Pt). There are also 34 known synthetic radioisotopes, the longest-lived of which is 193Pt with a half-life of 50 years. All other isotopes have half-lives under a year, most under a day. All isotopes of platinum are either radioactive or observationally stable, meaning that they are predicted to be radioactive but no actual decay has been observed. Platinum-195 is the most abundant isotope.
Natural hafnium (72Hf) consists of five observationally stable isotopes (176Hf, 177Hf, 178Hf, 179Hf, and 180Hf) and one very long-lived radioisotope, 174Hf, with a half-life of 7.0×1016 years. In addition, there are 34 known synthetic radioisotopes, the most stable of which is 182Hf with a half-life of 8.9×106 years. This extinct radionuclide is used in hafnium–tungsten dating to study the chronology of planetary differentiation.
Naturally occurring erbium (68Er) is composed of six stable isotopes, with 166Er being the most abundant. Thirty-nine radioisotopes have been characterized with between 74 and 112 neutrons, or 142 to 180 nucleons, with the most stable being 169Er with a half-life of 9.4 days, 172Er with a half-life of 49.3 hours, 160Er with a half-life of 28.58 hours, 165Er with a half-life of 10.36 hours, and 171Er with a half-life of 7.516 hours. All of the remaining radioactive isotopes have half-lives that are less than 3.5 hours, and the majority of these have half-lives that are less than 4 minutes. This element also has numerous meta states, with the most stable being 167mEr.
Natural holmium (67Ho) contains one observationally stable isotope, 165Ho. The below table lists 36 isotopes spanning 140Ho through 175Ho as well as 33 nuclear isomers. Among the known synthetic radioactive isotopes; the most stable one is 163Ho, with a half-life of 4,570 years. All other radioisotopes have half-lives not greater than 1.117 days in their ground states, and most have half-lives under 3 hours.
Naturally occurring dysprosium (66Dy) is composed of 7 stable isotopes, 156Dy, 158Dy, 160Dy, 161Dy, 162Dy, 163Dy and 164Dy, with 164Dy being the most abundant. Twenty-nine radioisotopes have been characterized, with the most stable being 154Dy with a half-life of 1.4 million years, 159Dy with a half-life of 144.4 days, and 166Dy with a half-life of 81.6 hours. All of the remaining radioactive isotopes have half-lives that are less than 10 hours, and the majority of these have half-lives that are less than 30 seconds. This element also has 12 meta states, with the most stable being 165mDy, 147mDy and 145mDy.
Naturally occurring terbium (65Tb) is composed of one stable isotope, 159Tb. Thirty-seven radioisotopes have been characterized, with the most stable being 158Tb with a half-life of 180 years, 157Tb with a half-life of 71 years, and 160Tb with a half-life of 72.3 days. All of the remaining radioactive isotopes have half-lives that are less than 6.907 days, and the majority of these have half-lives that are less than 24 seconds. This element also has 27 meta states, with the most stable being 156m1Tb, 154m2Tb and 154m1Tb.
Naturally occurring gadolinium (64Gd) is composed of 6 stable isotopes, 154Gd, 155Gd, 156Gd, 157Gd, 158Gd and 160Gd, and 1 radioisotope, 152Gd, with 158Gd being the most abundant (24.84% natural abundance). The predicted double beta decay of 160Gd has never been observed; only a lower limit on its half-life of more than 1.3×1021 years has been set experimentally.
Naturally occurring praseodymium (59Pr) is composed of one stable isotope, 141Pr. Thirty-eight radioisotopes have been characterized with the most stable being 143Pr, with a half-life of 13.57 days and 142Pr, with a half-life of 19.12 hours. All of the remaining radioactive isotopes have half-lives that are less than 5.985 hours and the majority of these have half-lives that are less than 33 seconds. This element also has 15 meta states with the most stable being 138mPr, 142mPr and 134mPr.
Naturally occurring lanthanum (57La) is composed of one stable (139La) and one radioactive (138La) isotope, with the stable isotope, 139La, being the most abundant (99.91% natural abundance). There are 39 radioisotopes that have been characterized, with the most stable being 138La, with a half-life of 1.02×1011 years; 137La, with a half-life of 60,000 years and 140La, with a half-life of 1.6781 days. The remaining radioactive isotopes have half-lives that are less than a day and the majority of these have half-lives that are less than 1 minute. This element also has 12 nuclear isomers, the longest-lived of which is 132mLa, with a half-life of 24.3 minutes. Lighter isotopes mostly decay to isotopes of barium and heavy ones mostly decay to isotopes of cerium. 138La can decay to both.
Naturally occurring barium (56Ba) is a mix of six stable isotopes and one very long-lived radioactive primordial isotope, barium-130, identified as being unstable by geochemical means (from analysis of the presence of its daughter xenon-130 in rocks) in 2001. This nuclide decays by double electron capture (absorbing two electrons and emitting two neutrinos), with a half-life of (0.5–2.7)×1021 years (about 1011 times the age of the universe).
Antimony (51Sb) occurs in two stable isotopes, 121Sb and 123Sb. There are 37 artificial radioactive isotopes, the longest-lived of which are 125Sb, with a half-life of 2.75856 years; 124Sb, with a half-life of 60.2 days; and 126Sb, with a half-life of 12.35 days. All other isotopes have half-lives less than 4 days, most less than an hour. There are also many isomers, the longest-lived of which is 120m1Sb with a half-life of 5.76 days.
Indium (49In) consists of two primordial nuclides, with the most common (~ 95.7%) nuclide (115In) being measurably though weakly radioactive. Its spin-forbidden decay has a half-life of 4.41×1014 years, much longer than the currently accepted age of the Universe.
Naturally occurring silver (47Ag) is composed of the two stable isotopes 107Ag and 109Ag in almost equal proportions, with 107Ag being slightly more abundant. Notably, silver is the only element with all stable istopes having nuclear spins of 1/2. Thus both 107Ag and 109Ag nuclei produce narrow lines in nuclear magnetic resonance spectra.
Bromine (35Br) has two stable isotopes, 79Br and 81Br, and 35 known radioisotopes, the most stable of which is 77Br, with a half-life of 57.036 hours.
Naturally occurring zinc (30Zn) is composed of the 5 stable isotopes 64Zn, 66Zn, 67Zn, 68Zn, and 70Zn with 64Zn being the most abundant. Twenty-eight radioisotopes have been characterised with the most stable being 65Zn with a half-life of 244.26 days, and then 72Zn with a half-life of 46.5 hours. All of the remaining radioactive isotopes have half-lives that are less than 14 hours and the majority of these have half-lives that are less than 1 second. This element also has 10 meta states.
Copper (29Cu) has two stable isotopes, 63Cu and 65Cu, along with 28 radioisotopes. The most stable radioisotope is 67Cu with a half-life of 61.83 hours. Most of the others have half-lives under a minute. Unstable copper isotopes with atomic masses below 63 tend to undergo β+ decay, while isotopes with atomic masses above 65 tend to undergo β− decay. 64Cu decays by both β+ and β−.
Naturally occurring vanadium (23V) is composed of one stable isotope 51V and one radioactive isotope 50V with a half-life of 2.71×1017 years. 24 artificial radioisotopes have been characterized (in the range of mass number between 40 and 65) with the most stable being 49V with a half-life of 330 days, and 48V with a half-life of 15.9735 days. All of the remaining radioactive isotopes have half-lives shorter than an hour, the majority of them below 10 seconds, the least stable being 42V with a half-life shorter than 55 nanoseconds, with all of the isotopes lighter than it, and none of the heavier, have unknown half-lives. In 4 isotopes, metastable excited states were found (including 2 metastable states for 60V), which adds up to 5 meta states.