Isotopes of mercury

There are seven stable isotopes of mercury (Hg) 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 radioisotopes have half-lives that are less than a day. ¹⁹⁹Hg and ²⁰¹Hg are the most often studied NMR-active nuclei, having spins of 1/2 and 3/2 respectively.

Mercury-180, producible from thallium-180 was found in 2010 to be capable of an unusual form of spontaneous fission.^[1]

Standard atomic mass: 200.59(2) u

Table

nuclide symbol	Z(p)	N(n)	isotopic mass (u)	half-life	decay mode(s)^[2]^{[n 1]}	daughter isotope(s)^{[n 2]}	nuclear spin	representative isotopic composition (mole fraction)	range of natural variation (mole fraction)
nuclide symbol	excitation energy			half-life	decay mode(s)^[2]^{[n 1]}	daughter isotope(s)^{[n 2]}	nuclear spin	representative isotopic composition (mole fraction)	range of natural variation (mole fraction)
¹⁷¹Hg	80	91	171.00376(32)#	80(30) µs [59(+36-16) µs]			3/2-#
¹⁷²Hg	80	92	171.99883(22)	420(240) µs [0.25(+35-9) ms]			0
¹⁷³Hg	80	93	172.99724(22)#	1.1(4) ms [0.6(+5-2) ms]			3/2-#
¹⁷⁴Hg	80	94	173.992864(21)	2.0(4) ms [2.1(+18-7) ms]			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 3]}	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⁺	¹⁹⁰Au	0+
¹⁹⁰Hg	80	110	189.966322(17)	20.0(5) min	α (5×10⁻⁵%)	¹⁸⁶Pt	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	¹⁹²Au	0+
¹⁹²Hg	80	112	191.965634(17)	4.85(20) h	α (4×10⁻⁶%)	¹⁸⁸Pt	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) a	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 4]}			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 5]}			0+	0.0997(20)
¹⁹⁹Hg	80	119	198.9682799(4)	Observationally Stable^{[n 6]}			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 7]}			0+	0.2310(19)
²⁰¹Hg	80	121	200.9703023(6)	Observationally Stable^{[n 8]}			3/2-	0.1318(9)
^201mHg	766.22(15) keV			94(3) µs			13/2+
²⁰²Hg	80	122	201.9706430(6)	Observationally Stable^{[n 9]}			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+
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+

^ Abbreviations:
EC: Electron capture
IT: Isomeric transition
^ Bold for stable isotopes
^ When produced from ¹⁸⁰Tl can also undergo fission to ¹⁰⁰Ru and ⁸⁰Kr
^ Believed to undergo α decay to ¹⁹²Pt or β⁺β⁺ decay to ¹⁹⁶Pt with a half-life over 2.5×10¹⁸ years
^ 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 α decay to ²⁰⁰Pt or β^-β^- decay to ²⁰⁴Pb

Notes

Values marked # are not purely derived from experimental data, but at least partly from systematic trends. Spins with weak assignment arguments are enclosed in parentheses.
Uncertainties are given in concise form in parentheses after the corresponding last digits. Uncertainty values denote one standard deviation, except isotopic composition and standard atomic mass from IUPAC which use expanded uncertainties.

References

Isotope masses from:
- G. Audi, A. H. Wapstra, C. Thibault, J. Blachot and O.. Bersillon (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. http://www.nndc.bnl.gov/amdc/nubase/Nubase2003.pdf.
Isotopic compositions and standard atomic masses from:
- J. R. de Laeter, J. K. Böhlke, P. De Bièvre, H. Hidaka, H. S. Peiser, K. J. R. Rosman and P. D. P. Taylor (2003). "Atomic weights of the elements. Review 2000 (IUPAC Technical Report)". Pure and Applied Chemistry 75 (6): 683–800. doi:10.1351/pac200375060683. http://www.iupac.org/publications/pac/75/6/0683/pdf/.
- M. E. Wieser (2006). "Atomic weights of the elements 2005 (IUPAC Technical Report)". Pure and Applied Chemistry 78 (11): 2051–2066. doi:10.1351/pac200678112051. http://iupac.org/publications/pac/78/11/2051/pdf/. Lay summary.
Half-life, spin, and isomer data selected from the following sources. See editing notes on this article's talk page.
- G. Audi, A. H. Wapstra, C. Thibault, J. Blachot and O. Bersillon (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. http://www.nndc.bnl.gov/amdc/nubase/Nubase2003.pdf.
- National Nuclear Data Center. "NuDat 2.1 database". Brookhaven National Laboratory. http://www.nndc.bnl.gov/nudat2/. Retrieved September 2005.
- N. E. Holden (2004). "Table of the Isotopes". In D. R. Lide. CRC Handbook of Chemistry and Physics (85th ed.). CRC Press. Section 11. ISBN 978-0849304859.

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