Isotopes of mercury

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.

Main isotopes of mercury (₈₀Hg)

Iso­tope Decay abun­dance half-life (t1/2) mode pro­duct ^194Hg syn 444 y ε ^194Au ^195Hg syn 9.9 h ε ^195Au ^196Hg 0.15% stable ^197Hg syn 64.14 h ε ^197Au ^198Hg 10.04% stable ^199Hg 16.94% stable ^200Hg 23.14% stable ^201Hg 13.17% stable ^202Hg 29.74% stable ^203Hg syn 46.612 d β^− ^203Tl ^204Hg 6.82% stable
Standard atomic weight Ar, standard(Hg)	200.592(3)[1]

¹⁸⁰Hg, producible from ¹⁸⁰Tl, was found in 2010 to be capable of an unusual form of spontaneous fission.[2] 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)
	Excitation energy[n 4]							Normal proportion	Range of variation
^170Hg[3]	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+
					β^+ (1.4%)	^176Au
^177Hg	80	97	176.98628(8)	127.3(18) ms	α (85%)	^173Pt	5/2−#
					β^+ (15%)	^177Au
^178Hg	80	98	177.982483(14)	0.269(3) s	α (70%)	^174Pt	0+
					β^+ (30%)	^178Au
^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+
					α (1.11%)	^180Pt
^185Hg	80	105	184.971899(17)	49.1(10) s	β^+ (94%)	^185Au	1/2−
					α (6%)	^181Pt
^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+
					α (.016%)	^182Pt
^186mHg	2217.3(4) keV			82(5) µs			(8−)
^187Hg	80	107	186.969814(15)	1.9(3) min	β^+	^187Au	3/2−
					α (1.2×10^−4%)	^183Pt
^187mHg	59(16) keV			2.4(3) min	β^+	^187Au	13/2+
					α (2.5×10^−4%)	^183Pt
^188Hg	80	108	187.967577(12)	3.25(15) min	β^+	^188Au	0+
					α (3.7×10^−5%)	^184Pt
^188mHg	2724.3(4) keV			134(15) ns			(12+)
^189Hg	80	109	188.96819(4)	7.6(1) min	β^+	^189Au	3/2−
					α (3×10^−5%)	^185Pt
^189mHg	80(30) keV			8.6(1) min	β^+	^189Au	13/2+
					α (3×10^−5%)	^185Pt
^190Hg	80	110	189.966322(17)	20.0(5) min	β^+	^190Au	0+
					α (5×10^−5%)	^186Pt
^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	^192Au	0+
					α (4×10^−6%)	^188Pt
^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+
					IT (7.1%)	^193Hg
^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+
					β^+ (45.8%)	^195Au
^196Hg	80	116	195.965833(3)	Observationally Stable[n 9]			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+
					EC (8.6%)	^197Au
^198Hg	80	118	197.9667690(4)	Stable			0+	0.0997(20)
^199Hg	80	119	198.9682799(4)	Stable			1/2−	0.1687(22)
^199mHg	532.48(10) keV			42.66(8) min	IT	^199Hg	13/2+
^200Hg	80	120	199.9683260(4)	Stable			0+	0.2310(19)
^201Hg	80	121	200.9703023(6)	Stable			3/2−	0.1318(9)
^201mHg	766.22(15) keV			94(3) µs			13/2+
^202Hg	80	122	201.9706430(6)	Stable			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 10]			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 11]
^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+

1. ^mHg – 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. # – 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
   SF:	Spontaneous fission

6. Bold symbol as daughter – Daughter product is stable.
7. ( ) spin value – Indicates spin with weak assignment arguments.
8. When produced from ¹⁸⁰Tl can also undergo fission to ¹⁰⁰Ru and ⁸⁰Kr
9. Believed to undergo β⁺β⁺ decay to ¹⁹⁶Pt with a half-life over 2.5×10¹⁸ years
10. Believed to undergo β^-β^- decay to ²⁰⁴Pb
11. Intermediate decay product of ²³⁸U

References

1. Meija, Juris; et al. (2016). "Atomic weights of the elements 2013 (IUPAC Technical Report)". Pure and Applied Chemistry. 88 (3): 265–91. doi:10.1515/pac-2015-0305.
2. Eugenie Samuel Reich (December 1, 2010). "Mercury serves up a nuclear surprise: a new type of fission". Scientific American.
3. Hilton, J.; et al. (2019). "α-spectroscopy studies of the new nuclides ¹⁶⁵Pt and ¹⁷⁰Hg". Physical Review C. 100 (1): 014305. doi:10.1103/PhysRevC.100.014305.

• 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. Lay summary.
• 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.