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.
|-id=Mercury-170| 170Hg| style="text-align:right" | 80| style="text-align:right" | 90| 170.00581(32)#| 310(250) μs| α| 166Pt| 0+|||-id=Mercury-171| 171Hg| style="text-align:right" | 80| style="text-align:right" | 91| 171.00359(33)#| 70(30) μs| α| 167Pt| 3/2−#|||-id=Mercury-172| 172Hg| style="text-align:right" | 80| style="text-align:right" | 92| 171.99886(16)| 231(9) μs| α| 168Pt| 0+|||-id=Mercury-173| 173Hg| style="text-align:right" | 80| style="text-align:right" | 93| 172.99714(22)#| 800(80) μs| α| 169Pt| (7/2−)|||-id=Mercury-174| 174Hg| style="text-align:right" | 80| style="text-align:right" | 94| 173.992871(21)| 2.0(4) ms| α| 170Pt| 0+|||-id=Mercury-175| 175Hg| style="text-align:right" | 80| style="text-align:right" | 95| 174.99144(9)| 10.2(3) ms| α| 171Pt| (7/2−)|||-id=Mercury-175m| style="text-indent:1em" | 175mHg| colspan="3" style="text-indent:2em" | 494(2) keV| 340(30) ns| IT| 175Hg| (13/2+)|||-id=Mercury-176| rowspan=2|176Hg| rowspan=2 style="text-align:right" | 80| rowspan=2 style="text-align:right" | 96| rowspan=2|175.987349(12)| rowspan=2|20.3(14) ms| α (90%)| 172Pt| rowspan=2|0+| rowspan=2|| rowspan=2||-| β+ (10%)| 176Au|-id=Mercury-177| 177Hg| style="text-align:right" | 80| style="text-align:right" | 97| 176.98628(9)| 117(7) ms| α| 173Pt| 7/2−| | |-id=Mercury-177m| style="text-indent:1em" | 177mHg| colspan="3" style="text-indent:2em" | 323.2(13) keV| 1.50(15) μs| IT| 177Hg| 13/2+|||-id=Mercury-178| rowspan=2|178Hg| rowspan=2 style="text-align:right" | 80| rowspan=2 style="text-align:right" | 98| rowspan=2|177.982485(12)| rowspan=2|266.5(24) ms| α (89%)| 174Pt| rowspan=2|0+| rowspan=2|| rowspan=2||-| β+ (11%)| 178Au|-id=Mercury-179| rowspan=3|179Hg| rowspan=3 style="text-align:right" | 80| rowspan=3 style="text-align:right" | 99| rowspan=3|178.98182(3)| rowspan=3|1.05(3) s| α (75%)| 175Pt| rowspan=3|7/2−| rowspan=3|| rowspan=3||-| β+ (25%)| 179Au|-| β+, p (0.15%)| 178Pt|-id=Mercury-179m| style="text-indent:1em" | 179mHg| colspan="3" style="text-indent:2em" | 171.4(4) keV| 6.4(9) μs| IT| 179Hg| 13/2+|||-id=Mercury-180| rowspan=2|180Hg| rowspan=2 style="text-align:right" | 80| rowspan=2 style="text-align:right" | 100| rowspan=2|179.978260(14)| rowspan=2|2.59(1) s| β+ (52%)| 180Au| rowspan=2|0+| rowspan=2|| rowspan=2||-| α (48%)| 176Pt|-id=Mercury-181| 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+ (73%)| 181Au| rowspan=4|1/2−| rowspan=4|| rowspan=4||-| α (27%)| 177Pt|-| β+, p (0.014%)| 180Pt|-| β+, α (9×10−6%)| 177Ir|-id=Mercury-181m| style="text-indent:1em" | 181mHg| colspan="3" style="text-indent:2em" | 210(50) keV| 480(20) μs| IT| 181Hg| 13/2+|||-id=Mercury-182| rowspan=3|182Hg| rowspan=3 style="text-align:right" | 80| rowspan=3 style="text-align:right" | 102| rowspan=3|181.974689(11)| rowspan=3|10.83(6) s| β+ (86.2%)| 182Au| rowspan=3|0+| rowspan=3|| rowspan=3||-| α (13.8%)| 178Pt|-| β+, p (<1×10−5%)| 181Pt|-id=Mercury-183| rowspan=3|183Hg| rowspan=3 style="text-align:right" | 80| rowspan=3 style="text-align:right" | 103| rowspan=3|182.974445(8)| rowspan=3|9.4(7) s| β+ (88.3%)| 183Au| rowspan=3|1/2−| rowspan=3|| rowspan=3||-| α (11.7%)| 179Pt|-| β+, p (2.6×10−4%)| 182Pt|-id=Mercury-183m| style="text-indent:1em" | 183mHg| colspan="3" style="text-indent:2em" | 204(14) keV| >5# μs||| 13/2+#|||-id=Mercury-184| rowspan=2|184Hg| rowspan=2 style="text-align:right" | 80| rowspan=2 style="text-align:right" | 104| rowspan=2|183.971718(10)| rowspan=2|30.87(26) s| β+ (98.89%)| 184Au| rowspan=2|0+| rowspan=2|| rowspan=2||-| α (1.11%)| 180Pt|-id=Mercury-185| rowspan=2|185Hg| rowspan=2 style="text-align:right" | 80| rowspan=2 style="text-align:right" | 105| rowspan=2|184.971891(15)| rowspan=2|49.1(10) s| β+ (94%)| 185Au| rowspan=2|1/2−| rowspan=2|| rowspan=2||-| α (6%)| 181Pt|-id=Mercury-185m| rowspan=3 style="text-indent:1em" | 185mHg| rowspan=3 colspan="3" style="text-indent:2em" | 103.7(4) keV| rowspan=3|21.6(15) s| IT (54%)| 185Hg| rowspan=3|13/2+| rowspan=3|| rowspan=3||-| β+ (46%)| 185Au|-| α (0.03%)| 181Pt|-id=Mercury-186| rowspan=2|186Hg| rowspan=2 style="text-align:right" | 80| rowspan=2 style="text-align:right" | 106| rowspan=2|185.969362(13)| rowspan=2|1.38(6) min| β+ (99.98%)| 186Au| rowspan=2|0+| rowspan=2|| rowspan=2||-| α (0.016%)| 182Pt|-id=Mercury-186m| style="text-indent:1em" | 186mHg| colspan="3" style="text-indent:2em" | 2217.3(4) keV| 82(5) μs| IT| 186Hg| (8−)|||-id=Mercury-187| 187Hg| style="text-align:right" | 80| style="text-align:right" | 107| 186.969814(14)| 1.9(3) min| β+| 187Au| 3/2−| | |-id=Mercury-187m| style="text-indent:1em" | 187mHg| colspan="3" style="text-indent:2em" | 58(14) keV| 2.4(3) min| β+| 187Au| 13/2+| | |-id=Mercury-188| rowspan=2|188Hg| rowspan=2 style="text-align:right" | 80| rowspan=2 style="text-align:right" | 108| rowspan=2|187.967581(7)| rowspan=2|3.25(15) min| β+| 188Au| rowspan=2|0+| rowspan=2|| rowspan=2||-| α (3.7×10−5%)| 184Pt|-id=Mercury-188m| style="text-indent:1em" | 188mHg| colspan="3" style="text-indent:2em" | 2724.1(4) keV| 142(14) ns| IT| 188Hg| 12+|||-id=Mercury-189| 189Hg| style="text-align:right" | 80| style="text-align:right" | 109| 188.96819(3)| 7.6(2) min| β+| 189Au| 3/2−| | |-id=Mercury-189m| style="text-indent:1em" | 189mHg| colspan="3" style="text-indent:2em" | 80(30) keV| 8.6(2) min| β+| 189Au| 13/2+| | |-id=Mercury-190| 190Hg| style="text-align:right" | 80| style="text-align:right" | 110| 189.966322(17)| 20.0(5) min| β+| 190Au| 0+|||-id=Mercury-191| 191Hg| style="text-align:right" | 80| style="text-align:right" | 111| 190.967158(24)| 49(10) min| β+| 191Au| 3/2−|||-id=Mercury-191m| style="text-indent:1em" | 191mHg| colspan="3" style="text-indent:2em" | 128(22) keV| 50.8(15) min| β+| 191Au| 13/2+|||-id=Mercury-192| 192Hg| style="text-align:right" | 80| style="text-align:right" | 112| 191.965634(17)| 4.85(20) h| EC| 192Au| 0+|||-id=Mercury-193| 193Hg| style="text-align:right" | 80| style="text-align:right" | 113| 192.966653(17)| 3.80(15) h| β+| 193Au| 3/2−|||-id=Mercury-193m| 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+ (92.8%)| 193Au| rowspan=2|13/2+| rowspan=2|| rowspan=2||-| IT (7.2%)| 193Hg|-id=Mercury-194| 194Hg| style="text-align:right" | 80| style="text-align:right" | 114| 193.965449(3)| 447(28) y| EC| 194Au| 0+|||-id=Mercury-195| 195Hg| style="text-align:right" | 80| style="text-align:right" | 115| 194.966706(25)| 10.69(16) h| β+| 195Au| 1/2−|||-id=Mercury-195m| rowspan=2 style="text-indent:1em" | 195mHg| rowspan=2 colspan="3" style="text-indent:2em" | 176.07(4) keV| rowspan=2|41.60(19) h| IT (54.2%)| 195Hg| rowspan=2|13/2+| rowspan=2|| rowspan=2||-| β+ (45.8%)| 195Au|-id=Mercury-196| 196Hg| style="text-align:right" | 80| style="text-align:right" | 116| 195.965833(3)| colspan=3 align=center|Observationally Stable[1] | 0+| 0.0015(1)||-id=Mercury-197| 197Hg| style="text-align:right" | 80| style="text-align:right" | 117| 196.967214(3)| 64.93(7) h| EC| 197Au| 1/2−|||-id=Mercury-197m| rowspan=2 style="text-indent:1em" | 197mHg| rowspan=2 colspan="3" style="text-indent:2em" | 298.93(8) keV| rowspan=2|23.82(4) h| IT (94.68%)| 197Hg| rowspan=2|13/2+| rowspan=2|| rowspan=2||-| EC (5.32%)| 197Au|-id=Mercury-198| 198Hg| style="text-align:right" | 80| style="text-align:right" | 118| 197.9667692(5)| colspan=3 align=center|Observationally Stable[2] | 0+| 0.1004(3)||-id=Mercury-199| 199Hg| style="text-align:right" | 80| style="text-align:right" | 119| 198.9682810(6)| colspan=3 align=center|Observationally Stable[3] | 1/2−| 0.1694(12)||-id=Mercury-199m| style="text-indent:1em" | 199mHg| colspan="3" style="text-indent:2em" | 532.48(10) keV| 42.67(9) min| IT| 199Hg| 13/2+|||-id=Mercury-200| 200Hg| style="text-align:right" | 80| style="text-align:right" | 120| 199.9683269(6)| colspan=3 align=center|Observationally Stable[4] | 0+| 0.2314(9)||-id=Mercury-201| 201Hg| style="text-align:right" | 80| style="text-align:right" | 121| 200.9703031(8)| colspan=3 align=center|Observationally Stable[5] | 3/2−| 0.1317(9)||-id=Mercury-201m| style="text-indent:1em" | 201mHg| colspan="3" style="text-indent:2em" | 766.22(15) keV| 94.0(20) μs| IT| 201Hg| 13/2+|||-id=Mercury-202| 202Hg| style="text-align:right" | 80| style="text-align:right" | 122| 201.9706436(8)| colspan=3 align=center|Observationally Stable[6] | 0+| 0.2974(13)||-id=Mercury-203| 203Hg| style="text-align:right" | 80| style="text-align:right" | 123| 202.9728724(18)| 46.610(10) d| β−| 203Tl| 5/2−|||-id=Mercury-203m1| style="text-indent:1em" | 203m1Hg| colspan="3" style="text-indent:2em" | 933.14(23) keV| 22.1(10) μs| IT| 203Hg| (13/2+)|||-id=Mercury-203m2| style="text-indent:1em" | 203m2Hg| colspan="3" style="text-indent:2em" | 8281.3(5) keV| 146(30) ns| IT| 203Hg| (53/2+)|||-id=Mercury-204| 204Hg| style="text-align:right" | 80| style="text-align:right" | 124| 203.9734940(5)| colspan=3 align=center|Observationally Stable[7] | 0+| 0.0682(4)||-id=Mercury-204m| style="text-indent:1em" | 204mHg| colspan="3" style="text-indent:2em" | 7226.08(17) keV| ~485 ns| IT| 204Hg| 22+|||-id=Mercury-205| 205Hg| style="text-align:right" | 80| style="text-align:right" | 125| 204.976073(4)| 5.14(9) min| β−| 205Tl| 1/2−|||-id=Mercury-205m1| style="text-indent:1em" | 205m1Hg| colspan="3" style="text-indent:2em" | 1556.4(3) keV| 1.09(4) ms| IT| 205Hg| 13/2+|||-id=Mercury-205m2| style="text-indent:1em" | 205m2Hg| colspan="3" style="text-indent:2em" | 3316.6(8) keV| 5.89(18) μs| IT| 205Hg| (23/2−)|||-id=Mercury-206| 206Hg| style="text-align:right" | 80| style="text-align:right" | 126| 205.977514(22)| 8.32(7) min| β−| 206Tl| 0+| Trace[8] ||-id=Mercury-206m1| style="text-indent:1em" | 206m1Hg| colspan="3" style="text-indent:2em" |2102.4(3) keV| 2.088(17) μs| IT| 206Hg| 5−|||-id=Mercury-206m2| style="text-indent:1em" | 206m2Hg| colspan="3" style="text-indent:2em" |3722.3(10) keV| 106(3) ns| IT| 206Hg| (10+)|||-id=Mercury-207| 207Hg| style="text-align:right" | 80| style="text-align:right" | 127| 206.98230(3)| 2.9(2) min| β−| 207Tl| 9/2+|||-id=Mercury-208| 208Hg| style="text-align:right" | 80| style="text-align:right" | 128| 207.98576(3)| 135(10) s| β−| 208Tl| 0+|||-id=Mercury-208m| style="text-indent:1em" | 208mHg| colspan="3" style="text-indent:2em" |1338(24) keV| 99(14) ns| IT| 208Hg| (8+)|||-id=Mercury-209| 209Hg| style="text-align:right" | 80| style="text-align:right" | 129| 208.99076(16)#| 6.3(11) s| β−| 209Tl| 9/2+#|||-id=Mercury-210| rowspan=2|210Hg| rowspan=2 style="text-align:right" | 80| rowspan=2 style="text-align:right" | 130| rowspan=2|209.99431(22)#| rowspan=2|64(12) s| β− (97.8%)| 210Tl| rowspan=2|0+| rowspan=2|| rowspan=2||-| β−, n (2.2%)| 209Tl|-id=Mercury-210m1| style="text-indent:1em" | 210m1Hg| colspan="3" style="text-indent:2em" |663(2) keV| 2.1(7) μs| IT| 210Hg| (3−)|||-id=Mercury-210m2| style="text-indent:1em" | 210m2Hg| colspan="3" style="text-indent:2em" |1406(23) keV| 2(1) μs| IT| 210Hg| 8+#|||-id=Mercury-211| rowspan=2|211Hg| rowspan=2 style="text-align:right" | 80| rowspan=2 style="text-align:right" | 131| rowspan=2|210.99958(22)#| rowspan=2|26.4(81) s| β− (93.7%)| 211Tl| rowspan=2|9/2+#| rowspan=2|| rowspan=2||-| β−, n (6.3%)| 210Tl|-id=Mercury-212| 212Hg| style="text-align:right" | 80| style="text-align:right" | 132| 212.00324(32)#| 30# s
[>300 ns]||| 0+|||-id=Mercury-213| 213Hg| style="text-align:right" | 80| style="text-align:right" | 133| 213.00880(32)#| 15# s
[>300 ns]||| 9/2+#|||-id=Mercury-214| 214Hg| style="text-align:right" | 80| style="text-align:right" | 134| 214.01264(43)#| 8# s
[>300 ns]||| 0+|||-id=Mercury-215| 215Hg| style="text-align:right" | 80| style="text-align:right" | 135| 215.01837(43)#| 600# ms
[>300 ns]||| 9/2+#|||-id=Mercury-216| 216Hg| style="text-align:right" | 80| style="text-align:right" | 136| 216.02246(43)#| 2# s
[>300 ns]||| 0+||