Isotopes of mercury (₈₀Hg)

Main isotopes^[1]			Decay
	abundance	half-life (t_1/2)	mode	product
¹⁹⁴Hg	synth	444 y	ε	¹⁹⁴Au
¹⁹⁵Hg	synth	9.9 h	ε	¹⁹⁵Au
¹⁹⁶Hg	0.15%	stable
¹⁹⁷Hg	synth	64.14 h	ε	¹⁹⁷Au
¹⁹⁸Hg	10.0%	stable
¹⁹⁹Hg	16.9%	stable
²⁰⁰Hg	23.1%	stable
²⁰¹Hg	13.2%	stable
²⁰²Hg	29.7%	stable
²⁰³Hg	synth	46.612 d	β⁻	²⁰³Tl
²⁰⁴Hg	6.82%	stable

Standard atomic weight A_r°(Hg)

200.592±0.003^[2]
200.59±0.01 (abridged)^[3]

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.

¹⁸⁰Hg, producible from ¹⁸⁰Tl, was found in 2010 to be capable of an unusual form of spontaneous fission.^[4] The fission products are ⁸⁰Kr and ¹⁰⁰Ru.

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]}	Spin and parity ^{[n 7]}^{[n 4]}	Natural abundance (mole fraction)
Nuclide ^{[n 1]}	Excitation energy^{[n 4]}			Half-life ^{[n 4]}	Decay mode ^{[n 5]}	Daughter isotope ^{[n 6]}	Spin and parity ^{[n 7]}^{[n 4]}	Normal proportion	Range of variation
¹⁷⁰Hg^[5]	80	90		80(+400-40) μs	α	¹⁶⁶Pt	0+
¹⁷¹Hg	80	91	171.00376(32)#	80(30) μs [59(+36−16) μs]	α	¹⁶⁷Pt	3/2−#
¹⁷²Hg	80	92	171.99883(22)	420(240) μs [0.25(+35−9) ms]	α	¹⁶⁸Pt	0+
¹⁷³Hg	80	93	172.99724(22)#	1.1(4) ms [0.6(+5−2) ms]	α	¹⁶⁹Pt	3/2−#
¹⁷⁴Hg	80	94	173.992864(21)	2.0(4) ms [2.1(+18−7) ms]	α	¹⁷⁰Pt	0+
¹⁷⁵Hg	80	95	174.99142(11)	10.8(4) ms	α	¹⁷¹Pt	5/2−#
¹⁷⁶Hg	80	96	175.987355(15)	20.4(15) ms	α (98.6%)	¹⁷²Pt	0+
¹⁷⁶Hg	80	96	175.987355(15)	20.4(15) ms	β⁺ (1.4%)	¹⁷⁶Au	0+
¹⁷⁷Hg	80	97	176.98628(8)	127.3(18) ms	α (85%)	¹⁷³Pt	5/2−#
¹⁷⁷Hg	80	97	176.98628(8)	127.3(18) ms	β⁺ (15%)	¹⁷⁷Au	5/2−#
¹⁷⁸Hg	80	98	177.982483(14)	0.269(3) s	α (70%)	¹⁷⁴Pt	0+
¹⁷⁸Hg	80	98	177.982483(14)	0.269(3) s	β⁺ (30%)	¹⁷⁸Au	0+
¹⁷⁹Hg	80	99	178.981834(29)	1.09(4) s	α (53%)	¹⁷⁵Pt	5/2−#
					β⁺ (47%)	¹⁷⁹Au
					β⁺, p (.15%)	¹⁷⁸Pt
¹⁸⁰Hg^{[n 8]}	80	100	179.978266(15)	2.58(1) s	β⁺ (52%)	¹⁸⁰Au	0+
					α (48%)	¹⁷⁶Pt
					SF	¹⁰⁰Ru, ⁸⁰Kr
¹⁸¹Hg	80	101	180.977819(17)	3.6(1) s	β⁺ (64%)	¹⁸¹Au	1/2(−)
					α (36%)	¹⁷⁷Pt
					β⁺, p (.014%)	¹⁸⁰Pt
					β⁺, α (9×10⁻⁶%)	¹⁷⁷Ir
^181mHg	210(40)# keV						13/2+
¹⁸²Hg	80	102	181.97469(1)	10.83(6) s	β⁺ (84.8%)	¹⁸²Au	0+
					α (15.2%)	¹⁷⁸Pt
					β⁺, p (10⁻⁵%)	¹⁸¹Pt
¹⁸³Hg	80	103	182.974450(9)	9.4(7) s	β⁺ (74.5%)	¹⁸³Au	1/2−
					α (25.5%)	¹⁷⁹Pt
					β⁺, p (5.6×10⁻⁴%)	¹⁸²Pt
^183m1Hg	198(14) keV						13/2+#
^183m2Hg	240(40)# keV			5# s	β⁺	¹⁸³Au	13/2+#
¹⁸⁴Hg	80	104	183.971713(11)	30.6(3) s	β⁺ (98.89%)	¹⁸⁴Au	0+
¹⁸⁴Hg	80	104	183.971713(11)	30.6(3) s	α (1.11%)	¹⁸⁰Pt	0+
¹⁸⁵Hg	80	105	184.971899(17)	49.1(10) s	β⁺ (94%)	¹⁸⁵Au	1/2−
¹⁸⁵Hg	80	105	184.971899(17)	49.1(10) s	α (6%)	¹⁸¹Pt	1/2−
^185mHg	99.3(5) keV			21.6(15) s	IT (54%)	¹⁸⁵Hg	13/2+
					β⁺ (46%)	¹⁸⁵Au
					α (.03%)	¹⁸¹Pt
¹⁸⁶Hg	80	106	185.969362(12)	1.38(6) min	β⁺ (99.92%)	¹⁸⁶Au	0+
¹⁸⁶Hg	80	106	185.969362(12)	1.38(6) min	α (.016%)	¹⁸²Pt	0+
^186mHg	2217.3(4) keV			82(5) μs			(8−)
¹⁸⁷Hg	80	107	186.969814(15)	1.9(3) min	β⁺	¹⁸⁷Au	3/2−
¹⁸⁷Hg	80	107	186.969814(15)	1.9(3) min	α (1.2×10⁻⁴%)	¹⁸³Pt	3/2−
^187mHg	59(16) keV			2.4(3) min	β⁺	¹⁸⁷Au	13/2+
^187mHg	59(16) keV			2.4(3) min	α (2.5×10⁻⁴%)	¹⁸³Pt	13/2+
¹⁸⁸Hg	80	108	187.967577(12)	3.25(15) min	β⁺	¹⁸⁸Au	0+
¹⁸⁸Hg	80	108	187.967577(12)	3.25(15) min	α (3.7×10⁻⁵%)	¹⁸⁴Pt	0+
^188mHg	2724.3(4) keV			134(15) ns			(12+)
¹⁸⁹Hg	80	109	188.96819(4)	7.6(1) min	β⁺	¹⁸⁹Au	3/2−
¹⁸⁹Hg	80	109	188.96819(4)	7.6(1) min	α (3×10⁻⁵%)	¹⁸⁵Pt	3/2−
^189mHg	80(30) keV			8.6(1) min	β⁺	¹⁸⁹Au	13/2+
^189mHg	80(30) keV			8.6(1) min	α (3×10⁻⁵%)	¹⁸⁵Pt	13/2+
¹⁹⁰Hg	80	110	189.966322(17)	20.0(5) min	β⁺^{[n 9]}	¹⁹⁰Au	0+
¹⁹¹Hg	80	111	190.967157(24)	49(10) min	β⁺	¹⁹¹Au	3/2(−)
^191mHg	128(22) keV			50.8(15) min	β⁺	¹⁹¹Au	13/2+
¹⁹²Hg	80	112	191.965634(17)	4.85(20) h	EC^{[n 10]}	¹⁹²Au	0+
¹⁹³Hg	80	113	192.966665(17)	3.80(15) h	β⁺	¹⁹³Au	3/2−
^193mHg	140.76(5) keV			11.8(2) h	β⁺ (92.9%)	¹⁹³Au	13/2+
^193mHg	140.76(5) keV			11.8(2) h	IT (7.1%)	¹⁹³Hg	13/2+
¹⁹⁴Hg	80	114	193.965439(13)	444(77) y	EC	¹⁹⁴Au	0+
¹⁹⁵Hg	80	115	194.966720(25)	10.53(3) h	β⁺	¹⁹⁵Au	1/2−
^195mHg	176.07(4) keV			41.6(8) h	IT (54.2%)	¹⁹⁵Hg	13/2+
^195mHg	176.07(4) keV			41.6(8) h	β⁺ (45.8%)	¹⁹⁵Au	13/2+
¹⁹⁶Hg	80	116	195.965833(3)	Observationally Stable^{[n 11]}			0+	0.0015(1)
¹⁹⁷Hg	80	117	196.967213(3)	64.14(5) h	EC	¹⁹⁷Au	1/2−
^197mHg	298.93(8) keV			23.8(1) h	IT (91.4%)	¹⁹⁷Hg	13/2+
^197mHg	298.93(8) keV			23.8(1) h	EC (8.6%)	¹⁹⁷Au	13/2+
¹⁹⁸Hg	80	118	197.9667690(4)	Observationally Stable^{[n 12]}			0+	0.0997(20)
¹⁹⁹Hg	80	119	198.9682799(4)	Observationally Stable^{[n 13]}			1/2−	0.1687(22)
^199mHg	532.48(10) keV			42.66(8) min	IT	¹⁹⁹Hg	13/2+
²⁰⁰Hg	80	120	199.9683260(4)	Observationally Stable^{[n 14]}			0+	0.2310(19)
²⁰¹Hg	80	121	200.9703023(6)	Observationally Stable^{[n 15]}			3/2−	0.1318(9)
^201mHg	766.22(15) keV			94(3) μs			13/2+
²⁰²Hg	80	122	201.9706430(6)	Observationally Stable^{[n 16]}			0+	0.2986(26)
²⁰³Hg	80	123	202.9728725(18)	46.595(6) d	β⁻	²⁰³Tl	5/2−
^203mHg	933.14(23) keV			24(4) μs			(13/2+)
²⁰⁴Hg	80	124	203.9734939(4)	Observationally Stable^{[n 17]}			0+	0.0687(15)
²⁰⁵Hg	80	125	204.976073(4)	5.14(9) min	β⁻	²⁰⁵Tl	1/2−
^205mHg	1556.40(17) keV			1.09(4) ms	IT	²⁰⁵Hg	13/2+
²⁰⁶Hg	80	126	205.977514(22)	8.15(10) min	β⁻	²⁰⁶Tl	0+	Trace^{[n 18]}
²⁰⁷Hg	80	127	206.98259(16)	2.9(2) min	β⁻	²⁰⁷Tl	(9/2+)
²⁰⁸Hg	80	128	207.98594(32)#	42(5) min [41(+5−4) min]	β⁻	²⁰⁸Tl	0+
²⁰⁹Hg	80	129	208.99104(21)#	37(8) s			9/2+#
²¹⁰Hg	80	130	209.99451(32)#	10# min [>300 ns]			0+
²¹¹Hg	80	131	210.99380(200)#	26(8) s			9/2+#
²¹²Hg	80	132	212.02760(300)#	1# min [>300 ns]			0+
²¹³Hg	80	133	213.07670(300)#	1# s [>300 ns]			5/2+#
²¹⁴Hg	80	134	214.11180(400)#	1# s [>300 ns]			0+
²¹⁵Hg	80	135	215.16210(400)#	1# s [>300 ns]			3/2+#
²¹⁶Hg	80	136	216.19860(400)#	100# ms [>300 ns]			0+
This table header & footer: view

^ ^mHg – Excited nuclear isomer.
^ ( ) – Uncertainty (1σ) is given in concise form in parentheses after the corresponding last digits.
^ # – Atomic mass marked #: value and uncertainty derived not from purely experimental data, but at least partly from trends from the Mass Surface (TMS).
^ ^a ^b ^c # – Values marked # are not purely derived from experimental data, but at least partly from trends of neighboring nuclides (TNN).
^ Modes of decay:

EC: Electron capture

IT: Isomeric transition

SF: Spontaneous fission
^ Bold symbol as daughter – Daughter product is stable.
^ ( ) spin value – Indicates spin with weak assignment arguments.
^ When produced from ¹⁸⁰Tl can also undergo fission to ¹⁰⁰Ru and ⁸⁰Kr
^ Theoretically capable of α decay to ¹⁸⁶Pt^[1]
^ Theoretically capable of α decay to ¹⁸⁸Pt^[1]
^ Believed to undergo β⁺β⁺ decay to ¹⁹⁶Pt with a half-life over 2.5×10¹⁸ years; also theorized to undergo α decay to ¹⁹²Pt
^ Believed to undergo α decay to ¹⁹⁴Pt
^ Believed to undergo α decay to ¹⁹⁵Pt
^ Believed to undergo α decay to ¹⁹⁶Pt
^ Believed to undergo α decay to ¹⁹⁷Pt
^ Believed to undergo α decay to ¹⁹⁸Pt
^ Believed to undergo β⁻β⁻ decay to ²⁰⁴Pb
^ Intermediate decay product of ²³⁸U

References

^ ^a ^b ^c 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.
^ "Standard Atomic Weights: Mercury". CIAAW. 2011.
^ Prohaska, Thomas; Irrgeher, Johanna; Benefield, Jacqueline; Böhlke, John K.; Chesson, Lesley A.; Coplen, Tyler B.; Ding, Tiping; Dunn, Philip J. H.; Gröning, Manfred; Holden, Norman E.; Meijer, Harro A. J. (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.
^ Eugenie Samuel Reich (December 1, 2010). "Mercury serves up a nuclear surprise: a new type of fission". Scientific American.
^ Hilton, J.; et al. (2019). "α-spectroscopy studies of the new nuclides ¹⁶⁵Pt and ¹⁷⁰Hg". Physical Review C. 100 (1): 014305. Bibcode:2019PhRvC.100a4305H. doi:10.1103/PhysRevC.100.014305. S2CID 199118719.

Isotope masses from:
- Audi, Georges; Bersillon, Olivier; Blachot, Jean; Wapstra, Aaldert Hendrik (2003), "The NUBASE evaluation of nuclear and decay properties", Nuclear Physics A, 729: 3–128, Bibcode:2003NuPhA.729....3A, doi:10.1016/j.nuclphysa.2003.11.001
- Audi, G.; Kondev, F. G.; Wang, M.; Huang, W. J.; Naimi, S. (2017). "The NUBASE2016 evaluation of nuclear properties" (PDF). Chinese Physics C. 41 (3): 030001. Bibcode:2017ChPhC..41c0001A. doi:10.1088/1674-1137/41/3/030001.
Isotopic compositions and standard atomic masses from:
- de Laeter, John Robert; Böhlke, John Karl; De Bièvre, Paul; Hidaka, Hiroshi; Peiser, H. Steffen; Rosman, Kevin J. R.; Taylor, Philip D. P. (2003). "Atomic weights of the elements. Review 2000 (IUPAC Technical Report)". Pure and Applied Chemistry. 75 (6): 683–800. doi:10.1351/pac200375060683.
- Wieser, Michael E. (2006). "Atomic weights of the elements 2005 (IUPAC Technical Report)". Pure and Applied Chemistry. 78 (11): 2051–2066. doi:10.1351/pac200678112051.
"News & Notices: Standard Atomic Weights Revised". International Union of Pure and Applied Chemistry. 19 October 2005.
Half-life, spin, and isomer data selected from the following sources.
- Audi, Georges; Bersillon, Olivier; Blachot, Jean; Wapstra, Aaldert Hendrik (2003), "The NUBASE evaluation of nuclear and decay properties", Nuclear Physics A, 729: 3–128, Bibcode:2003NuPhA.729....3A, doi:10.1016/j.nuclphysa.2003.11.001
- Audi, G.; Kondev, F. G.; Wang, M.; Huang, W. J.; Naimi, S. (2017). "The NUBASE2016 evaluation of nuclear properties" (PDF). Chinese Physics C. 41 (3): 030001. Bibcode:2017ChPhC..41c0001A. doi:10.1088/1674-1137/41/3/030001.
- National Nuclear Data Center. "NuDat 2.x database". Brookhaven National Laboratory.
- Holden, Norman E. (2004). "11. Table of the Isotopes". In Lide, David R. (ed.). CRC Handbook of Chemistry and Physics (85th ed.). Boca Raton, Florida: CRC Press. ISBN 978-0-8493-0485-9.

EC:	Electron capture
IT:	Isomeric transition
SF:	Spontaneous fission