Isotopes of gold
Encyclopedia
Gold
(Au) 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, but Bismuth-209
has been found to be slightly radioactive).
Gold has been proposed as a material for creating a salted nuclear weapon
(cobalt
is another, better-known salting material). A jacket of natural 197Au, irradiated by the intense high-energy neutron flux from an exploding thermonuclear weapon, would transmute into the radioactive isotope 198Au with a half-life 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.
The highest amount of 198Au detected in any United States nuclear test was in shot "Sedan"
detonated at Nevada Test Site
on July 6, 1962.
Standard atomic mass: 196.966569(4) u
Gold
Gold is a chemical element with the symbol Au and an atomic number of 79. Gold is a dense, soft, shiny, malleable and ductile metal. Pure gold has a bright yellow color and luster traditionally considered attractive, which it maintains without oxidizing in air or water. Chemically, gold is a...
(Au) has one stable isotope
Isotope
Isotopes are variants of atoms of a particular chemical element, which have differing numbers of neutrons. Atoms of a particular element by definition must contain the same number of protons but may have a distinct number of neutrons which differs from atom to atom, without changing the designation...
, 197Au, and 36 radioisotopes with 195Au being the most stable with a half-life
Half-life
Half-life, abbreviated t½, is the period of time it takes for the amount of a substance undergoing decay to decrease by half. The name was originally used to describe a characteristic of unstable atoms , but it may apply to any quantity which follows a set-rate decay.The original term, dating to...
of 186 days.
Gold is currently considered the heaviest Monoisotopic element
Monoisotopic element
A monoisotopic element is one of 26 chemical elements which have only a single stable isotope . A list is given in a following section....
(Bismuth
Bismuth
Bismuth is a chemical element with symbol Bi and atomic number 83. Bismuth, a trivalent poor metal, chemically resembles arsenic and antimony. Elemental bismuth may occur naturally uncombined, although its sulfide and oxide form important commercial ores. The free element is 86% as dense as lead...
formerly held that distinction, but Bismuth-209
Bismuth-209
Bismuth-209 is the isotope of bismuth with the longest half-life. It has 83 protons and 126 neutrons, and an atomic mass of 208.9803987 u. All primordial bismuth is of this isotope...
has been found to be slightly radioactive).
Gold has been proposed as a material for creating a salted nuclear weapon
Salted bomb
A salted bomb is a variation of a nuclear weapon designed to produce enhanced quantities of radioactive fallout, rendering a large area uninhabitable...
(cobalt
Cobalt
Cobalt is a chemical element with symbol Co and atomic number 27. It is found naturally only in chemically combined form. The free element, produced by reductive smelting, is a hard, lustrous, silver-gray metal....
is another, better-known salting material). A jacket of natural 197Au, irradiated by the intense high-energy neutron flux from an exploding thermonuclear weapon, would transmute into the radioactive isotope 198Au with a half-life of 2.697 days and produce approximately .411 MeV
MEV
MeV and meV are multiples and submultiples of the electron volt unit referring to 1,000,000 eV and 0.001 eV, respectively.Mev or MEV may refer to:In entertainment:* Musica Elettronica Viva, an Italian musical group...
of gamma radiation
Gamma ray
Gamma radiation, also known as gamma rays or hyphenated as gamma-rays and denoted as γ, is electromagnetic radiation of high frequency . Gamma rays are usually naturally produced on Earth by decay of high energy states in atomic nuclei...
, significantly increasing the radioactivity of the weapon's fallout
Nuclear fallout
Fallout is the residual radioactive material propelled into the upper atmosphere following a nuclear blast, so called because it "falls out" of the sky after the explosion and shock wave have passed. It commonly refers to the radioactive dust and ash created when a nuclear weapon explodes...
for several days. Such a weapon is not known to have ever been built, tested, or used.
The highest amount of 198Au detected in any United States nuclear test was in shot "Sedan"
Sedan (nuclear test)
Storax Sedan was a shallow underground nuclear test conducted in Area 10 of Yucca Flat at the Nevada National Security Site on 6 July 1962 as part of Operation Plowshare, a program to investigate the use of nuclear weapons for mining, cratering, and other civilian purposes...
detonated at Nevada Test Site
Nevada Test Site
The Nevada National Security Site , previously the Nevada Test Site , is a United States Department of Energy reservation located in southeastern Nye County, Nevada, about northwest of the city of Las Vegas...
on July 6, 1962.
Standard atomic mass: 196.966569(4) u
Table
| nuclide symbol |
Z(p Proton The proton is a subatomic particle with the symbol or and a positive electric charge of 1 elementary charge. One or more protons are present in the nucleus of each atom, along with neutrons. The number of protons in each atom is its atomic number.... ) |
N(n Neutron The neutron is a subatomic hadron particle which has the symbol or , no net electric charge and a mass slightly larger than that of a proton. With the exception of hydrogen, nuclei of atoms consist of protons and neutrons, which are therefore collectively referred to as nucleons. The number of... ) |
isotopic mass (u) |
half-life | decay mode(s)Abbreviations: EC: Electron capture Electron capture Electron capture is a process in which a proton-rich nuclide absorbs an inner atomic electron and simultaneously emits a neutrino... IT: Isomeric transition Isomeric transition An isomeric transition is a radioactive decay process that involves emission of a gamma ray from an atom where the nucleus is in an excited metastable state, referred to in its excited state, as a nuclear isomer.... |
daughter isotope(s)Bold for stable isotopes, bold italics for nearly-stable isotopes (half-life longer than the age of the universe Age of the universe The age of the universe is the time elapsed since the Big Bang posited by the most widely accepted scientific model of cosmology. The best current estimate of the age of the universe is 13.75 ± 0.13 billion years within the Lambda-CDM concordance model... ) |
nuclear spin |
representative isotopic composition (mole fraction) |
range of natural variation (mole fraction) |
|---|---|---|---|---|---|---|---|---|---|
| excitation energy | |||||||||
| 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 Proton emission Proton emission is a type of radioactive decay in which a proton is ejected from a nucleus. Proton emission can occur from high-lying excited states in a nucleus following a beta decay, in which case the process is known as beta-delayed proton emission, or can occur from the ground state of very... |
170Pt | (1/2+) | ||
| α Alpha decay Alpha decay is a type of radioactive decay in which an atomic nucleus emits an alpha particle and thereby transforms into an atom with a mass number 4 less and atomic number 2 less... (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+ Beta decay In nuclear physics, beta decay is a type of radioactive decay in which a beta particle is emitted from an atom. There are two types of beta decay: beta minus and beta plus. In the case of beta decay that produces an electron emission, it is referred to as beta minus , while in the case of a... (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 Isomeric transition An isomeric transition is a radioactive decay process that involves emission of a gamma ray from an atom where the nucleus is in an excited metastable state, referred to in its excited state, as a nuclear isomer.... (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 Electron capture Electron capture is a process in which a proton-rich nuclide absorbs an inner atomic electron and simultaneously emits a neutrino... |
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- | ||||||
| 197AuPotential material for salted bomb Salted bomb A salted bomb is a variation of a nuclear weapon designed to produce enhanced quantities of radioactive fallout, rendering a large area uninhabitable... s |
79 | 118 | 196.9665687(6) | Observationally StableBelieved to undergo α decay to 193Ir | 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+ | ||
| 202Au | 79 | 123 | 201.97381(18) | 28.8(19) s | β- | 202Hg | (1-) | ||
| 203Au | 79 | 124 | 202.975155(3) | 53(2) s | β- | 203Hg | 3/2+ | ||
| 204Au | 79 | 125 | 203.97772(22)# | 39.8(9) s | β- | 204Hg | (2-) | ||
| 205Au | 79 | 126 | 204.97987(32)# | 31(2) s | β- | 205Hg | 3/2+ | ||