There are seven 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 ...

s of mercury (₈₀Hg) with ²⁰²Hg being the most abundant (29.86%). The longest-lived

radioisotope 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 ...

s are ¹⁹⁴Hg 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 444 years, and ²⁰³Hg with a half-life of 46.612 days. Most of the remaining 40

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 ...

have half-lives that are less than a day. ¹⁹⁹Hg and ²⁰¹Hg are the most often studied

NMR Nuclear magnetic resonance (NMR) is a physical phenomenon in which nuclei in a strong constant magnetic field are perturbed by a weak oscillating magnetic field (in the near field) and respond by producing an electromagnetic signal with ...

-active nuclei, having spin quantum numbers of 1/2 and 3/2 respectively. All isotopes of mercury are either radioactive or

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 they are predicted to be radioactive but no actual decay has been observed. These isotopes are predicted to undergo either

alpha decay Alpha decay or α-decay is a type of radioactive decay in which an atomic nucleus emits an alpha particle (helium nucleus) and thereby transforms or 'decays' into a different atomic nucleus, with a mass number that is reduced by four and an at ...

double beta decay In nuclear physics, double beta decay is a type of radioactive decay in which two neutrons are simultaneously transformed into two protons, or vice versa, inside an atomic nucleus. As in single beta decay, this process allows the atom to move clos ...

. ¹⁸⁰Hg, producible from ¹⁸⁰Tl, was found in 2010 to be capable of an unusual form of spontaneous fission. The fission products are ⁸⁰Kr and ¹⁰⁰Ru.

List of isotopes

, - , ¹⁷⁰Hg , style="text-align:right" , 80 , style="text-align:right" , 90 , , 80(+400-40) μs , α , ¹⁶⁶Pt , 0+ , , , - , ¹⁷¹Hg , style="text-align:right" , 80 , style="text-align:right" , 91 , 171.00376(32)# , 80(30) μs
9(+36−16) μs, α , ¹⁶⁷Pt , 3/2−# , , , - , ¹⁷²Hg , style="text-align:right" , 80 , style="text-align:right" , 92 , 171.99883(22) , 420(240) μs
.25(+35−9) ms, α , ¹⁶⁸Pt , 0+ , , , - , ¹⁷³Hg , style="text-align:right" , 80 , style="text-align:right" , 93 , 172.99724(22)# , 1.1(4) ms
.6(+5−2) ms, α , ¹⁶⁹Pt , 3/2−# , , , - , ¹⁷⁴Hg , style="text-align:right" , 80 , style="text-align:right" , 94 , 173.992864(21) , 2.0(4) ms
.1(+18−7) ms, α , ¹⁷⁰Pt , 0+ , , , - , ¹⁷⁵Hg , style="text-align:right" , 80 , style="text-align:right" , 95 , 174.99142(11) , 10.8(4) ms , α , ¹⁷¹Pt , 5/2−# , , , - , rowspan=2, ¹⁷⁶Hg , rowspan=2 style="text-align:right" , 80 , rowspan=2 style="text-align:right" , 96 , rowspan=2, 175.987355(15) , rowspan=2, 20.4(15) ms , α (98.6%) , ¹⁷²Pt , rowspan=2, 0+ , rowspan=2, , rowspan=2, , - , β⁺ (1.4%) , ¹⁷⁶Au , - , rowspan=2, ¹⁷⁷Hg , rowspan=2 style="text-align:right" , 80 , rowspan=2 style="text-align:right" , 97 , rowspan=2, 176.98628(8) , rowspan=2, 127.3(18) ms , α (85%) , ¹⁷³Pt , rowspan=2, 5/2−# , rowspan=2, , rowspan=2, , - , β⁺ (15%) , ¹⁷⁷Au , - , rowspan=2, ¹⁷⁸Hg , rowspan=2 style="text-align:right" , 80 , rowspan=2 style="text-align:right" , 98 , rowspan=2, 177.982483(14) , rowspan=2, 0.269(3) s , α (70%) , ¹⁷⁴Pt , rowspan=2, 0+ , rowspan=2, , rowspan=2, , - , β⁺ (30%) , ¹⁷⁸Au , - , rowspan=3, ¹⁷⁹Hg , rowspan=3 style="text-align:right" , 80 , rowspan=3 style="text-align:right" , 99 , rowspan=3, 178.981834(29) , rowspan=3, 1.09(4) s , α (53%) , ¹⁷⁵Pt , rowspan=3, 5/2−# , rowspan=3, , rowspan=3, , - , β⁺ (47%) , ¹⁷⁹Au , - , β⁺, p (.15%) , ¹⁷⁸Pt , - , rowspan=3, ¹⁸⁰HgWhen produced from ¹⁸⁰Tl can also undergo fission to ¹⁰⁰Ru and ⁸⁰Kr , rowspan=3 style="text-align:right" , 80 , rowspan=3 style="text-align:right" , 100 , rowspan=3, 179.978266(15) , rowspan=3, 2.58(1) s , β⁺ (52%) , ¹⁸⁰Au , rowspan=3, 0+ , rowspan=3, , rowspan=3, , - , α (48%) , ¹⁷⁶Pt , - , SF , ¹⁰⁰Ru, ⁸⁰Kr , - , rowspan=4, ¹⁸¹Hg , rowspan=4 style="text-align:right" , 80 , rowspan=4 style="text-align:right" , 101 , rowspan=4, 180.977819(17) , rowspan=4, 3.6(1) s , β⁺ (64%) , ¹⁸¹Au , rowspan=4, 1/2(−) , rowspan=4, , rowspan=4, , - , α (36%) , ¹⁷⁷Pt , - , β⁺, p (.014%) , ¹⁸⁰Pt , - , β⁺, α (9×10⁻⁶%) , ¹⁷⁷Ir , - , style="text-indent:1em" , ^181mHg , colspan="3" style="text-indent:2em" , 210(40)# keV , , , , 13/2+ , , , - , rowspan=3, ¹⁸²Hg , rowspan=3 style="text-align:right" , 80 , rowspan=3 style="text-align:right" , 102 , rowspan=3, 181.97469(1) , rowspan=3, 10.83(6) s , β⁺ (84.8%) , ¹⁸²Au , rowspan=3, 0+ , rowspan=3, , rowspan=3, , - , α (15.2%) , ¹⁷⁸Pt , - , β⁺, p (10⁻⁵%) , ¹⁸¹Pt , - , rowspan=3, ¹⁸³Hg , rowspan=3 style="text-align:right" , 80 , rowspan=3 style="text-align:right" , 103 , rowspan=3, 182.974450(9) , rowspan=3, 9.4(7) s , β⁺ (74.5%) , ¹⁸³Au , rowspan=3, 1/2− , rowspan=3, , rowspan=3, , - , α (25.5%) , ¹⁷⁹Pt , - , β⁺, p (5.6×10⁻⁴%) , ¹⁸²Pt , - , style="text-indent:1em" , ^183m1Hg , colspan="3" style="text-indent:2em" , 198(14) keV , , , , 13/2+# , , , - , style="text-indent:1em" , ^183m2Hg , colspan="3" style="text-indent:2em" , 240(40)# keV , 5# s , β⁺ , ¹⁸³Au , 13/2+# , , , - , rowspan=2, ¹⁸⁴Hg , rowspan=2 style="text-align:right" , 80 , rowspan=2 style="text-align:right" , 104 , rowspan=2, 183.971713(11) , rowspan=2, 30.6(3) s , β⁺ (98.89%) , ¹⁸⁴Au , rowspan=2, 0+ , rowspan=2, , rowspan=2, , - , α (1.11%) , ¹⁸⁰Pt , - , rowspan=2, ¹⁸⁵Hg , rowspan=2 style="text-align:right" , 80 , rowspan=2 style="text-align:right" , 105 , rowspan=2, 184.971899(17) , rowspan=2, 49.1(10) s , β⁺ (94%) , ¹⁸⁵Au , rowspan=2, 1/2− , rowspan=2, , rowspan=2, , - , α (6%) , ¹⁸¹Pt , - , rowspan=3 style="text-indent:1em" , ^185mHg , rowspan=3 colspan="3" style="text-indent:2em" , 99.3(5) keV , rowspan=3, 21.6(15) s , IT (54%) , ¹⁸⁵Hg , rowspan=3, 13/2+ , rowspan=3, , rowspan=3, , - , β⁺ (46%) , ¹⁸⁵Au , - , α (.03%) , ¹⁸¹Pt , - , rowspan=2, ¹⁸⁶Hg , rowspan=2 style="text-align:right" , 80 , rowspan=2 style="text-align:right" , 106 , rowspan=2, 185.969362(12) , rowspan=2, 1.38(6) min , β⁺ (99.92%) , ¹⁸⁶Au , rowspan=2, 0+ , rowspan=2, , rowspan=2, , - , α (.016%) , ¹⁸²Pt , - , style="text-indent:1em" , ^186mHg , colspan="3" style="text-indent:2em" , 2217.3(4) keV , 82(5) μs , , , (8−) , , , - , rowspan=2, ¹⁸⁷Hg , rowspan=2 style="text-align:right" , 80 , rowspan=2 style="text-align:right" , 107 , rowspan=2, 186.969814(15) , rowspan=2, 1.9(3) min , β⁺ , ¹⁸⁷Au , rowspan=2, 3/2− , rowspan=2, , rowspan=2, , - , α (1.2×10⁻⁴%) , ¹⁸³Pt , - , rowspan=2 style="text-indent:1em" , ^187mHg , rowspan=2 colspan="3" style="text-indent:2em" , 59(16) keV , rowspan=2, 2.4(3) min , β⁺ , ¹⁸⁷Au , rowspan=2, 13/2+ , rowspan=2, , rowspan=2, , - , α (2.5×10⁻⁴%) , ¹⁸³Pt , - , rowspan=2, ¹⁸⁸Hg , rowspan=2 style="text-align:right" , 80 , rowspan=2 style="text-align:right" , 108 , rowspan=2, 187.967577(12) , rowspan=2, 3.25(15) min , β⁺ , ¹⁸⁸Au , rowspan=2, 0+ , rowspan=2, , rowspan=2, , - , α (3.7×10⁻⁵%) , ¹⁸⁴Pt , - , style="text-indent:1em" , ^188mHg , colspan="3" style="text-indent:2em" , 2724.3(4) keV , 134(15) ns , , , (12+) , , , - , rowspan=2, ¹⁸⁹Hg , rowspan=2 style="text-align:right" , 80 , rowspan=2 style="text-align:right" , 109 , rowspan=2, 188.96819(4) , rowspan=2, 7.6(1) min , β⁺ , ¹⁸⁹Au , rowspan=2, 3/2− , rowspan=2, , rowspan=2, , - , α (3×10⁻⁵%) , ¹⁸⁵Pt , - , rowspan=2 style="text-indent:1em" , ^189mHg , rowspan=2 colspan="3" style="text-indent:2em" , 80(30) keV , rowspan=2, 8.6(1) min , β⁺ , ¹⁸⁹Au , rowspan=2, 13/2+ , rowspan=2, , rowspan=2, , - , α (3×10⁻⁵%) , ¹⁸⁵Pt , - , rowspan=2, ¹⁹⁰Hg , rowspan=2 style="text-align:right" , 80 , rowspan=2 style="text-align:right" , 110 , rowspan=2, 189.966322(17) , rowspan=2, 20.0(5) min , β⁺ , ¹⁹⁰Au , rowspan=2, 0+ , rowspan=2, , rowspan=2, , - , α (5×10⁻⁵%) , ¹⁸⁶Pt , - , ¹⁹¹Hg , style="text-align:right" , 80 , style="text-align:right" , 111 , 190.967157(24) , 49(10) min , β⁺ , ¹⁹¹Au , 3/2(−) , , , - , style="text-indent:1em" , ^191mHg , colspan="3" style="text-indent:2em" , 128(22) keV , 50.8(15) min , β⁺ , ¹⁹¹Au , 13/2+ , , , - , rowspan=2, ¹⁹²Hg , rowspan=2 style="text-align:right" , 80 , rowspan=2 style="text-align:right" , 112 , rowspan=2, 191.965634(17) , rowspan=2, 4.85(20) h , EC , ¹⁹²Au , rowspan=2, 0+ , rowspan=2, , rowspan=2, , - , α (4×10⁻⁶%) , ¹⁸⁸Pt , - , ¹⁹³Hg , style="text-align:right" , 80 , style="text-align:right" , 113 , 192.966665(17) , 3.80(15) h , β⁺ , ¹⁹³Au , 3/2− , , , - , rowspan=2 style="text-indent:1em" , ^193mHg , rowspan=2 colspan="3" style="text-indent:2em" , 140.76(5) keV , rowspan=2, 11.8(2) h , β⁺ (92.9%) , ¹⁹³Au , rowspan=2, 13/2+ , rowspan=2, , rowspan=2, , - , IT (7.1%) , ¹⁹³Hg , - , ¹⁹⁴Hg , style="text-align:right" , 80 , style="text-align:right" , 114 , 193.965439(13) , 444(77) y , EC , ¹⁹⁴Au , 0+ , , , - , ¹⁹⁵Hg , style="text-align:right" , 80 , style="text-align:right" , 115 , 194.966720(25) , 10.53(3) h , β⁺ , ¹⁹⁵Au , 1/2− , , , - , rowspan=2 style="text-indent:1em" , ^195mHg , rowspan=2 colspan="3" style="text-indent:2em" , 176.07(4) keV , rowspan=2, 41.6(8) h , IT (54.2%) , ¹⁹⁵Hg , rowspan=2, 13/2+ , rowspan=2, , rowspan=2, , - , β⁺ (45.8%) , ¹⁹⁵Au , - , ¹⁹⁶Hg , style="text-align:right" , 80 , style="text-align:right" , 116 , 195.965833(3) , 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 β⁺β⁺ decay to ¹⁹⁶Pt with a half-life over 2.5×10¹⁸ years , 0+ , 0.0015(1) , , - , ¹⁹⁷Hg , style="text-align:right" , 80 , style="text-align:right" , 117 , 196.967213(3) , 64.14(5) h , EC , ¹⁹⁷Au , 1/2− , , , - , rowspan=2 style="text-indent:1em" , ^197mHg , rowspan=2 colspan="3" style="text-indent:2em" , 298.93(8) keV , rowspan=2, 23.8(1) h , IT (91.4%) , ¹⁹⁷Hg , rowspan=2, 13/2+ , rowspan=2, , rowspan=2, , - , EC (8.6%) , ¹⁹⁷Au , - , ¹⁹⁸Hg , style="text-align:right" , 80 , style="text-align:right" , 118 , 197.9667690(4) , colspan=3 align=center, Observationally StableBelieved to undergo α decay to ¹⁹⁴Pt , 0+ , 0.0997(20) , , - , ¹⁹⁹Hg , style="text-align:right" , 80 , style="text-align:right" , 119 , 198.9682799(4) , colspan=3 align=center, Observationally StableBelieved to undergo α decay to ¹⁹⁵Pt , 1/2− , 0.1687(22) , , - , style="text-indent:1em" , ^199mHg , colspan="3" style="text-indent:2em" , 532.48(10) keV , 42.66(8) min , IT , ¹⁹⁹Hg , 13/2+ , , , - , ²⁰⁰Hg , style="text-align:right" , 80 , style="text-align:right" , 120 , 199.9683260(4) , colspan=3 align=center, Observationally StableBelieved to undergo α decay to ¹⁹⁶Pt , 0+ , 0.2310(19) , , - , ²⁰¹Hg , style="text-align:right" , 80 , style="text-align:right" , 121 , 200.9703023(6) , colspan=3 align=center, Observationally StableBelieved to undergo α decay to ¹⁹⁷Pt , 3/2− , 0.1318(9) , , - , style="text-indent:1em" , ^201mHg , colspan="3" style="text-indent:2em" , 766.22(15) keV , 94(3) μs , , , 13/2+ , , , - , ²⁰²Hg , style="text-align:right" , 80 , style="text-align:right" , 122 , 201.9706430(6) , colspan=3 align=center, Observationally StableBelieved to undergo α decay to ¹⁹⁸Pt , 0+ , 0.2986(26) , , - , ²⁰³Hg , style="text-align:right" , 80 , style="text-align:right" , 123 , 202.9728725(18) , 46.595(6) d , β⁻ , ²⁰³Tl , 5/2− , , , - , style="text-indent:1em" , ^203mHg , colspan="3" style="text-indent:2em" , 933.14(23) keV , 24(4) μs , , , (13/2+) , , , - , ²⁰⁴Hg , style="text-align:right" , 80 , style="text-align:right" , 124 , 203.9734939(4) , colspan=3 align=center, Observationally StableBelieved to undergo β⁻β⁻ decay to ²⁰⁴Pb , 0+ , 0.0687(15) , , - , ²⁰⁵Hg , style="text-align:right" , 80 , style="text-align:right" , 125 , 204.976073(4) , 5.14(9) min , β⁻ , ²⁰⁵Tl , 1/2− , , , - , style="text-indent:1em" , ^205mHg , colspan="3" style="text-indent:2em" , 1556.40(17) keV , 1.09(4) ms , IT , ²⁰⁵Hg , 13/2+ , , , - , ²⁰⁶Hg , style="text-align:right" , 80 , style="text-align:right" , 126 , 205.977514(22) , 8.15(10) min , β⁻ , ²⁰⁶Tl , 0+ , TraceIntermediate decay product of ²³⁸U , , - , ²⁰⁷Hg , style="text-align:right" , 80 , style="text-align:right" , 127 , 206.98259(16) , 2.9(2) min , β⁻ , ²⁰⁷Tl , (9/2+) , , , - , ²⁰⁸Hg , style="text-align:right" , 80 , style="text-align:right" , 128 , 207.98594(32)# , 42(5) min
1(+5−4) min, β⁻ , ²⁰⁸Tl , 0+ , , , - , ²⁰⁹Hg , style="text-align:right" , 80 , style="text-align:right" , 129 , 208.99104(21)# , 37(8) s , , , 9/2+# , , , - , ²¹⁰Hg , style="text-align:right" , 80 , style="text-align:right" , 130 , 209.99451(32)# , 10# min
300 ns, , , 0+ , , , - , ²¹¹Hg , style="text-align:right" , 80 , style="text-align:right" , 131 , 210.99380(200)# , 26(8) s , , , 9/2+# , , , - , ²¹²Hg , style="text-align:right" , 80 , style="text-align:right" , 132 , 212.02760(300)# , 1# min
300 ns, , , 0+ , , , - , ²¹³Hg , style="text-align:right" , 80 , style="text-align:right" , 133 , 213.07670(300)# , 1# s
300 ns, , , 5/2+# , , , - , ²¹⁴Hg , style="text-align:right" , 80 , style="text-align:right" , 134 , 214.11180(400)# , 1# s
300 ns, , , 0+ , , , - , ²¹⁵Hg , style="text-align:right" , 80 , style="text-align:right" , 135 , 215.16210(400)# , 1# s
300 ns, , , 3/2+# , , , - , ²¹⁶Hg , style="text-align:right" , 80 , style="text-align:right" , 136 , 216.19860(400)# , 100# ms
300 ns, , , 0+ , ,

Particular Isotopes

Hg-196

While it is the rarest stable isotope of Mercury, at a proportion lower than that of in natural uranium, Hg-196 is of some theoretical interest in the synthesis of precious metals via nuclear transmutation since it could - in theory - be transmutated into the only stable gold isotope via

neutron absorption Neutron capture is a nuclear reaction in which an atomic nucleus and one or more neutrons collide and merge to form a heavier nucleus. Since neutrons have no electric charge, they can enter a nucleus more easily than positively charged protons, ...

and subsequent decay via

electron capture Electron capture (K-electron capture, also K-capture, or L-electron capture, L-capture) is a process in which the proton-rich nucleus of an electrically neutral atom absorbs an inner atomic electron, usually from the K or L electron shells. Thi ...

. However, given that a costly step of

isotope separation Isotope separation is the process of concentrating specific isotopes of a chemical element by removing other isotopes. The use of the nuclides produced is varied. The largest variety is used in research (e.g. in chemistry where atoms of "marker" n ...

would have to precede the already costly process of transmutation, this has (as of 2022) mostly remained a theoretical curiosity rather than an actual area of research.

Hg-198

At roughly 10% of natural Mercury, Hg-198 is neither particularly abundant nor particularly rare. It has a non-negligible

gamma ray cross section Gamma ray cross section - a measure of the probability that gamma ray interacts with matter. The total cross section of gamma ray interactions is composed of several independent processes: photoelectric effect, Compton scattering, electron-positron ...

for the ( γ, n) reaction with 10 Mega-

Electronvolt In physics, an electronvolt (symbol eV, also written electron-volt and electron volt) is the measure of an amount of kinetic energy gained by a single electron accelerating from rest through an electric potential difference of one volt in vacuum ...

Gamma Rays. This reaction, in addition to serving as a potential

neutron source A neutron source is any device that emits neutrons, irrespective of the mechanism used to produce the neutrons. Neutron sources are used in physics, engineering, medicine, nuclear weapons, petroleum exploration, biology, chemistry, and nuclear p ...

could also be used to produce Hg-197 and via electron capture produce - stable gold. Given that it is roughly two

orders of magnitude An order of magnitude is an approximation of the logarithm of a value relative to some contextually understood reference value, usually 10, interpreted as the base of the logarithm and the representative of values of magnitude one. Logarithmic dis ...

more abundant that Hg-196, the required isotopic separation, even it required a further step of separating the lighter Hg-196 from the heavier Hg-198 could be achieved with a better yield for any given effort than for Hg-196.

References

* Isotope masses from: ** ** * Isotopic compositions and standard atomic masses from: ** ** * Half-life, spin, and isomer data selected from the following sources. ** ** ** ** {{Authority control Mercury