Isotopes of gold

Last updated
Isotopes of gold  (79Au)
Main isotopes [1] Decay
abun­dance half-life (t1/2) mode pro­duct
195Au synth 186.01 d ε 195Pt
196Ausynth6.165 d β+ 196Pt
β 196Hg
197Au100% stable
198Au synth2.69464 dβ 198Hg
199Ausynth3.139 dβ 199Hg
Standard atomic weight Ar°(Au)

Gold (79Au) has one stable isotope, 197Au, and 37 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]

List of isotopes

Nuclide
[n 1]
Z N Isotopic mass (Da)
[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 proportionRange of variation
169Au [5] 7990168.99808(32)#1.16+0.50
−0.47
 μs
p (~94%)168Pt(11/2−)
α (~6%)165mIr
170Au [6] 7991169.99612(22)#286+50
−40
 μs
p (89%)169Pt(2−)
α (11%)166Ir
170mAu [7] 282(10) keV617+50
−40
 μs
p (58%)169Pt(9+)
α (42%)166mIr
171Au7992170.991879(28)22+3
−2
 μs
[8]
p (100%)170Pt(1/2+)
α (rare)167Ir
171mAu258(13) keV1.014(19) msα (66%)167mIr11/2−
p (34%)170Pt
172Au7993171.99004(17)#4.7(11) msα (98%)168Irhigh
p (2%)171Pt
173Au7994172.986237(28)25(1) msα169Ir(1/2+)
β+ (rare)173Pt
173mAu214(23) keV14.0(9) msα (96%)169Ir(11/2−)
β+ (4%)173Pt
174Au7995173.98476(11)#139(3) msα170Irlow
β+ (rare)174Pt
174mAu360(70)# keV171(29) mshigh
175Au7996174.98127(5)100# msα (82%)171Ir1/2+#
β+ (18%)175Pt
175mAu200(30)# keV156(3) msα171Ir11/2−#
β+175Pt
176Au7997175.98010(11)#1.08(17) s
[0.84(+17−14) s]
α (60%)172Ir(5−)
β+ (40%)176Pt
176mAu150(100)# keV860(160) ms(7+)
177Au7998176.976865(14)1.462(32) sβ+ (60%)177Pt(1/2+, 3/2+)
α (40%)173Ir
177mAu216(26) keV1.180(12) s11/2−
178Au7999177.97603(6)2.6(5) sβ+ (60%)178Pt
α (40%)174Ir
179Au79100178.973213(18)7.1(3) sβ+ (78%)179Pt5/2−#
α (22%)175Ir
179mAu99(16) keV(11/2−)
180Au79101179.972521(23)8.1(3) sβ+ (98.2%)180Pt
α (1.8%)176Ir
181Au79102180.970079(21)13.7(14) sβ+ (97.3%)181Pt(3/2−)
α (2.7%)177Ir
182Au79103181.969618(22)15.5(4) sβ+ (99.87%)182Pt(2+)
α (.13%)178Ir
183Au79104182.967593(11)42.8(10) sβ+ (99.2%)183Pt(5/2)−
α (.8%)179Ir
183m1Au73.3(4) keV>1 μs(1/2)+
183m2Au230.6(6) keV<1 μs(11/2)−
184Au79105183.967452(24)20.6(9) sβ+184Pt5+
184mAu68.46(1) keV47.6(14) sβ+ (70%)184Pt2+
IT (30%)184Au
α (.013%)180Ir
185Au79106184.965789(28)4.25(6) minβ+ (99.74%)185Pt5/2−
α (.26%)181Ir
185mAu100(100)# keV6.8(3) min1/2+#
186Au79107185.965953(23)10.7(5) minβ+ (99.9992%)186Pt3−
α (8×10−4%)182Ir
186mAu227.77(7) keV110(10) ns2+
187Au79108186.964568(27)8.4(3) minβ+ (99.997%)187Pt1/2+
α (.003%)183Ir
187mAu120.51(16) keV2.3(1) sIT187Au9/2−
188Au79109187.965324(22)8.84(6) minβ+188Pt1(−)
189Au79110188.963948(22)28.7(3) minβ+ (99.9997%)189Pt1/2+
α (3×10−4%)185Ir
189m1Au247.23(16) keV4.59(11) minβ+189Pt11/2−
IT (rare)189Au
189m2Au325.11(16) keV190(15) ns9/2−
189m3Au2554.7(12) keV242(10) ns31/2+
190Au79111189.964700(17)42.8(10) minβ+190Pt1−
α (<10−6%)186Ir
190mAu200(150)# keV125(20) msIT190Au11−#
β+ (rare)190Pt
191Au79112190.96370(4)3.18(8) hβ+191Pt3/2+
191m1Au266.2(5) keV920(110) msIT191Au(11/2−)
191m2Au2490(1) keV>400 ns
192Au79113191.964813(17)4.94(9) hβ+192Pt1−
192m1Au135.41(25) keV29 msIT192Au(5#)+
192m2Au431.6(5) keV160(20) ms(11−)
193Au79114192.964150(11)17.65(15) hβ+ [n 9] 193Pt3/2+
193m1Au290.19(3) keV3.9(3) sIT (99.97%)193Au11/2−
β+ (.03%)193Pt
193m2Au2486.5(6) keV150(50) ns(31/2+)
194Au79115193.965365(11)38.02(10) hβ+194Pt1−
194m1Au107.4(5) keV600(8) msIT194Au(5+)
194m2Au475.8(6) keV420(10) ms(11−)
195Au79116194.9650346(14)186.098(47) d EC 195Pt3/2+
195mAu318.58(4) keV30.5(2) sIT195Au11/2−
196Au79117195.966570(3)6.1669(6) dβ+ (93.05%)196Pt2−
β (6.95%)196Hg
196m1Au84.660(20) keV8.1(2) sIT196Au5+
196m2Au595.66(4) keV9.6(1) h12−
197Au [n 10] 79118196.9665687(6) Observationally Stable [n 11] 3/2+1.0000
197mAu409.15(8) keV7.73(6) sIT197Au11/2−
198Au 79119197.9682423(6)2.69517(21) dβ198Hg2−
198m1Au312.2200(20) keV124(4) ns5+
198m2Au811.7(15) keV2.27(2) dIT198Au(12−)
199Au79120198.9687652(6)3.139(7) dβ199Hg3/2+
199mAu548.9368(21) keV440(30) μs(11/2)−
200Au79121199.97073(5)48.4(3) minβ200Hg1(−)
200mAu970(70) keV18.7(5) hβ (82%)200Hg12−
IT (18%)200Au
201Au79122200.971657(3)26(1) minβ201Hg3/2+
201m1Au594(5) keV730(630) μs(11/2-)
201m2Au1610(5) keV5.6(2.4) μs(11/2-)
202Au79123201.97381(18)28.8(19) sβ202Hg(1−)
203Au79124202.975155(3)60(6) sβ203Hg3/2+
203mAu641(3) keV140(44) μsIT203Au11/2−#
204Au79125203.97772(22)#38.3(1.3) sβ204Hg(2−)
204mAu3816(1000)# keV2.1(0.3) μsIT204Au16+#
205Au79126204.97985(21)#32.5(1.4) sβ205Hg3/2+#
205m1Au907(5) keV6(2) s11/2−#
205m2Au2850(5) keV163(5) ns19/2+#
206Au79127205.98474(32)#47(11) sβ206Hg(5+, 6+)
This table header & footer:
  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. 1 2 3 #  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. Theoretically capable of α decay to 189Ir [1]
  10. Potential material for salted bombs
  11. Theoretically predicted to undergo α decay to 193Ir

Related Research Articles

Radium (88Ra) has no stable or nearly stable isotopes, and thus a standard atomic weight cannot be given. The longest lived, and most common, isotope of radium is 226Ra with a half-life of 1600 years. 226Ra occurs in the decay chain of 238U. Radium has 34 known isotopes from 201Ra to 234Ra.

Francium (87Fr) has no stable isotopes. A standard atomic weight cannot be given. Its most stable isotope is 223Fr with a half-life of 22 minutes, occurring in trace quantities in nature as an intermediate decay product of 235U.

There are 39 known isotopes of radon (86Rn), from 193Rn to 231Rn; all are radioactive. The most stable isotope is 222Rn with a half-life of 3.823 days, which decays into 218
Po
. Six isotopes of radon, 217, 218, 219, 220, 221, 222Rn, occur in trace quantities in nature as decay products of, respectively, 217At, 218At, 223Ra, 224Ra, 225Ra, and 226Ra. 217Rn and 221Rn are produced in rare branches in the decay chain of trace quantities of 237Np; 222Rn is an intermediate step in the decay chain of 238U; 219Rn is an intermediate step in the decay chain of 235U; and 220Rn occurs in the decay chain of 232Th.

Astatine (85At) has 41 known isotopes, all of which are radioactive; their mass numbers range from 188 to 229. There are also 24 known metastable excited states. The longest-lived isotope is 210At, which has a half-life of 8.1 hours; the longest-lived isotope existing in naturally occurring decay chains is 219At with a half-life of 56 seconds.

Lead (82Pb) has four observationally stable isotopes: 204Pb, 206Pb, 207Pb, 208Pb. Lead-204 is entirely a primordial nuclide and is not a radiogenic nuclide. The three isotopes lead-206, lead-207, and lead-208 represent the ends of three decay chains: the uranium series, the actinium series, and the thorium series, respectively; a fourth decay chain, the neptunium series, terminates with the thallium isotope 205Tl. The three series terminating in lead represent the decay chain products of long-lived primordial 238U, 235U, and 232Th. Each isotope also occurs, to some extent, as primordial isotopes that were made in supernovae, rather than radiogenically as daughter products. The fixed ratio of lead-204 to the primordial amounts of the other lead isotopes may be used as the baseline to estimate the extra amounts of radiogenic lead present in rocks as a result of decay from uranium and thorium.

There are two natural isotopes of iridium (77Ir), and 37 radioisotopes, the most stable radioisotope being 192Ir with a half-life of 73.83 days, and many nuclear isomers, the most stable of which is 192m2Ir with a half-life of 241 years. All other isomers have half-lives under a year, most under a day. All isotopes of iridium are either radioactive or observationally stable, meaning that they are predicted to be radioactive but no actual decay has been observed.

Naturally occurring rhenium (75Re) is 37.4% 185Re, which is stable (although it is predicted to decay), and 62.6% 187Re, which is unstable but has a very long half-life (4.12×1010 years). Among elements with a known stable isotope, only indium and tellurium similarly occur with a stable isotope in lower abundance than the long-lived radioactive isotope.

Naturally occurring tungsten (74W) consists of five isotopes. Four are considered stable (182W, 183W, 184W, and 186W) and one is slightly radioactive, 180W, with an extremely long half-life of 1.8 ± 0.2 exayears (1018 years). On average, two alpha decays of 180W occur per gram of natural tungsten per year, so for most practical purposes, 180W can be considered stable. Theoretically, all five can decay into isotopes of element 72 (hafnium) by alpha emission, but only 180W has been observed to do so. The other naturally occurring isotopes have not been observed to decay (they are observationally stable), and lower bounds for their half-lives have been established:

Natural tantalum (73Ta) consists of two stable isotopes: 181Ta (99.988%) and 180m
Ta
(0.012%).

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 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.

<span class="mw-page-title-main">Isotopes of lanthanum</span> Nuclides with atomic number of 57 but with different mass numbers

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.

Antimony (51Sb) occurs in two stable isotopes, 121Sb and 123Sb. There are 35 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.

Naturally occurring rhodium (45Rh) is composed of only one stable isotope, 103Rh. The most stable radioisotopes are 101Rh with a half-life of 3.3 years, 102Rh with a half-life of 207 days, and 99Rh with a half-life of 16.1 days. Thirty other radioisotopes have been characterized with atomic weights ranging from 88.949 u (89Rh) to 121.943 u (122Rh). Most of these have half-lives that are less than an hour except 100Rh and 105Rh. There are also numerous meta states with the most stable being 102mRh (0.141 MeV) with a half-life of about 3.7 years and 101mRh (0.157 MeV) with a half-life of 4.34 days.

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.

Naturally occurring scandium (21Sc) is composed of one stable isotope, 45Sc. Twenty-five radioisotopes have been characterized, with the most stable being 46Sc with a half-life of 83.8 days, 47Sc with a half-life of 3.35 days, and 48Sc with a half-life of 43.7 hours and 44Sc with a half-life of 3.97 hours. All the remaining isotopes have half-lives that are less than four hours, and the majority of these have half-lives that are less than two minutes, the least stable being proton unbound 39Sc with a half-life shorter than 300 nanoseconds. This element also has 13 meta states with the most stable being 44m2Sc.

Fermium (100Fm) is a synthetic element, and thus a standard atomic weight cannot be given. Like all artificial elements, it has no stable isotopes. The first isotope to be discovered was 255Fm in 1952. 250Fm was independently synthesized shortly after the discovery of 255Fm. There are 20 known radioisotopes ranging in atomic mass from 241Fm to 260Fm, and 4 nuclear isomers, 247mFm, 250mFm, 251mFm, and 253mFm. The longest-lived isotope is 257Fm with a half-life of 100.5 days, and the longest-lived isomer is 247mFm with a half-life of 5.1 seconds.

Einsteinium (99Es) is a synthetic element, and thus a standard atomic weight cannot be given. Like all synthetic elements, it has no stable isotopes. The first isotope to be discovered was 253Es in 1952. There are 18 known radioisotopes from 240Es to 257Es, and 3 nuclear isomers. The longest-lived isotope is 252Es with a half-life of 471.7 days, or around 1.293 years.

Mendelevium (101Md) is a synthetic element, and thus a standard atomic weight cannot be given. Like all artificial elements, it has no stable isotopes. The first isotope to be synthesized was 256Md in 1955. There are 17 known radioisotopes, ranging in atomic mass from 244Md to 260Md, and 5 isomers. The longest-lived isotope is 258Md with a half-life of 51.3 days, and the longest-lived isomer is 258mMd with a half-life of 57 minutes.

Lawrencium (103Lr) is a synthetic element, and thus a standard atomic weight cannot be given. Like all synthetic elements, it has no stable isotopes. The first isotope to be synthesized was 258Lr in 1961. There are fourteen known isotopes from 251Lr to 266Lr, and seven isomers. The longest-lived known isotope is 266Lr with a half-life of 11 hours.

References

  1. 1 2 Kondev, F. G.; Wang, M.; Huang, W. J.; Naimi, S.; Audi, G. (2021). "The NUBASE2020 evaluation of nuclear properties" (PDF). Chinese Physics C. 45 (3): 030001. doi:10.1088/1674-1137/abddae.
  2. "Standard Atomic Weights: Gold". CIAAW. 2017.
  3. Prohaska, Thomas; Irrgeher, Johanna; Benefield, Jacqueline; et al. (2022-05-04). "Standard atomic weights of the elements 2021 (IUPAC Technical Report)". Pure and Applied Chemistry. doi:10.1515/pac-2019-0603. ISSN   1365-3075.
  4. Belli, P.; Bernabei, R.; Danevich, F. A.; et al. (2019). "Experimental searches for rare alpha and beta decays". European Physical Journal A. 55 (8): 140–1–140–7. arXiv: 1908.11458 . Bibcode:2019EPJA...55..140B. doi:10.1140/epja/i2019-12823-2. ISSN   1434-601X. S2CID   201664098.
  5. Hilton, Joshua Ben. "Decays of new nuclides 169Au, 170Hg, 165Pt and the ground state of 165Ir discovered using MARA" (PDF). University of Liverpool. Retrieved 11 June 2023.
  6. Kettunen, H.; Enqvist, T.; Grahn, T.; Greenlees, P. T.; Jones, P.; Julin, R.; Juutinen, S.; Keenan, A.; Kuusiniemi, P.; Leino, M.; Leppänen, A.-P.; Nieminen, P.; Pakarinen, J.; Rahkila, P.; Uusitalo, J. (28 May 2004). "Decay studies of Au 170 , 171 , Hg 171 – 173 , and Tl 176". Physical Review C. 69 (5): 054323. doi:10.1103/PhysRevC.69.054323. ISSN   0556-2813.
  7. Kettunen, H.; Enqvist, T.; Grahn, T.; Greenlees, P. T.; Jones, P.; Julin, R.; Juutinen, S.; Keenan, A.; Kuusiniemi, P.; Leino, M.; Leppänen, A.-P.; Nieminen, P.; Pakarinen, J.; Rahkila, P.; Uusitalo, J. (28 May 2004). "Decay studies of Au 170 , 171 , Hg 171 – 173 , and Tl 176". Physical Review C. 69 (5): 054323. doi:10.1103/PhysRevC.69.054323. ISSN   0556-2813 . Retrieved 11 June 2023.
  8. Kettunen, H.; Enqvist, T.; Grahn, T.; Greenlees, P. T.; Jones, P.; Julin, R.; Juutinen, S.; Keenan, A.; Kuusiniemi, P.; Leino, M.; Leppänen, A.-P.; Nieminen, P.; Pakarinen, J.; Rahkila, P.; Uusitalo, J. (28 May 2004). "Decay studies of Au 170 , 171 , Hg 171 – 173 , and Tl 176". Physical Review C. 69 (5): 054323. doi:10.1103/PhysRevC.69.054323. ISSN   0556-2813 . Retrieved 11 June 2023.