Isotopes of tungsten

Isotopes of tungsten (₇₄W)
Standard atomic weight Ar°(W)
	183.84±0.01; 183.84±0.01 (abridged);
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Naturally occurring tungsten (₇₄W) consists of five isotopes. Four are considered stable (¹⁸²W, ¹⁸³W, ¹⁸⁴W, and ¹⁸⁶W) and one is slightly radioactive, ¹⁸⁰W, with an extremely long half-life of (1.59±0.05)×10¹⁸ years.^[1] On average, two alpha decays of ¹⁸⁰W occur per gram of natural tungsten per year, so for most practical purposes, ¹⁸⁰W can be considered stable. Theoretically, all five naturally occurring isotopes of tungsten can decay into isotopes of hafnium (element 72) by alpha emission, but only ¹⁸⁰W has been observed to do so. The other naturally occurring isotopes have not been observed to decay (they are observationally stable), and lower bounds for their half-lives have been established:

¹⁸²W, t_1/2 > 7.7×10²¹ years

¹⁸³W, t_1/2 > 4.1×10²¹ years

¹⁸⁴W, t_1/2 > 8.9×10²¹ years

¹⁸⁶W, t_1/2 > 8.2×10²¹ years

Thirty-four artificial radioisotopes of tungsten have been characterized with mass numbers ranging from 156 to 194, the most stable of which are ¹⁸¹W with a half-life of 121.2 days, ¹⁸⁵W with a half-life of 75.1 days, ¹⁸⁸W with a half-life of 69.4 days and ¹⁷⁸W with a half-life of 21.6 days. All of the remaining radioactive isotopes have half-lives of less than 24 hours, and most of these have half-lives that are less than 8 minutes. Tungsten also has twelve known meta states, the most stable being ^179m1W (t_1/2 6.4 minutes).

List of isotopes

Nuclide ^{[n 1]}	Z	N	Isotopic mass (Da)^[4] ^{[n 2]}^{[n 3]}	Half-life^[5] ^{[n 4]}^{[n 5]}	Decay mode^[5] ^{[n 6]}	Daughter isotope ^{[n 7]}^{[n 8]}	Spin and parity^[5] ^{[n 9]}^{[n 5]}	Natural abundance (mole fraction)
Nuclide ^{[n 1]}	Excitation energy			Half-life^[5] ^{[n 4]}^{[n 5]}	Decay mode^[5] ^{[n 6]}	Daughter isotope ^{[n 7]}^{[n 8]}	Spin and parity^[5] ^{[n 9]}^{[n 5]}	Normal proportion^[5]	Range of variation
¹⁵⁶W^[6]	74	82		157+57 −34 ms	β⁺	¹⁵⁶Ta	0+
¹⁵⁷W^[7]	74	83	156.97886(43)#	275(40) ms	β⁺	¹⁵⁷Ta	(7/2−)
¹⁵⁸W	74	84	157.97457(32)#	1.43(18) ms	α	¹⁵⁴Hf	0+
^158mW	1889(8) keV			143(19) μs	α	¹⁵⁴Hf	(8+)
¹⁵⁹W	74	85	158.97270(32)#	8.2(7) ms	α (82%)	¹⁵⁵Hf	7/2−#
¹⁶⁰W	74	86	159.96851(16)	90(5) ms	α (87%)	¹⁵⁶Hf	0+
¹⁶⁰W	74	86	159.96851(16)	90(5) ms	β⁺ (13%)	¹⁶⁰Ta	0+
¹⁶¹W	74	87	160.96725(22)#	409(16) ms	α (73%)	¹⁵⁷Hf	7/2−#
¹⁶¹W	74	87	160.96725(22)#	409(16) ms	β⁺ (27%)	¹⁶¹Ta	7/2−#
¹⁶²W	74	88	161.963500(19)	1.19(12) s	β⁺ (54.8%)	¹⁶²Ta	0+
¹⁶²W	74	88	161.963500(19)	1.19(12) s	α (45.2%)	¹⁵⁸Hf	0+
¹⁶³W	74	89	162.962524(63)	2.63(9) s	β⁺ (86%)	¹⁶³Ta	7/2−
¹⁶³W	74	89	162.962524(63)	2.63(9) s	α (14%)	¹⁵⁹Hf	7/2−
^163mW	480.3(7) keV			154(3) ns	IT	¹⁶³W	13/2+
¹⁶⁴W	74	90	163.958952(10)	6.3(2) s	β⁺ (96.2%)	¹⁶⁴Ta	0+
¹⁶⁴W	74	90	163.958952(10)	6.3(2) s	α (3.8%)	¹⁶⁰Hf	0+
¹⁶⁵W	74	91	164.958281(28)	5.1(5) s	β⁺	¹⁶⁵Ta	(5/2−)
¹⁶⁶W	74	92	165.955032(10)	19.2(6) s	β⁺ (99.97%)	¹⁶⁶Ta	0+
¹⁶⁶W	74	92	165.955032(10)	19.2(6) s	α (0.035%)	¹⁶²Hf	0+
¹⁶⁷W	74	93	166.954811(20)	19.9(5) s	β⁺ (99.96%)	¹⁶⁷Ta	(5/2−)
¹⁶⁷W	74	93	166.954811(20)	19.9(5) s	α (0.04%)	¹⁶³Hf	(5/2−)
¹⁶⁸W	74	94	167.951805(14)	50.9(19) s	β⁺ (99.97%)	¹⁶⁸Ta	0+
¹⁶⁸W	74	94	167.951805(14)	50.9(19) s	α (0.032%)	¹⁶⁴Hf	0+
¹⁶⁹W	74	95	168.951779(17)	74(6) s	β⁺	¹⁶⁹Ta	5/2−#
¹⁷⁰W	74	96	169.949231(14)	2.42(4) min	β⁺(99%)	¹⁷⁰Ta	0+
¹⁷¹W	74	97	170.949451(30)	2.38(4) min	β⁺	¹⁷¹Ta	(5/2−)
¹⁷²W	74	98	171.947292(30)	6.6(9) min	β⁺	¹⁷²Ta	0+
¹⁷³W	74	99	172.947689(30)	7.6(2) min	β⁺	¹⁷³Ta	5/2−
¹⁷⁴W	74	100	173.946079(30)	33.2(21) min	β⁺	¹⁷⁴Ta	0+
^174m1W	2267.8(4) keV			158(3) ns	IT	¹⁷⁴W	8−
^174m2W	3515.6(4) keV			128(8) ns	IT	¹⁷⁴W	12+
¹⁷⁵W	74	101	174.946717(30)	35.2(6) min	β⁺	¹⁷⁵Ta	(1/2−)
^175mW	234.96(15) keV			216(6) ns	IT	¹⁷⁵W	(7/2+)
¹⁷⁶W	74	102	175.945634(30)	2.5(1) h	EC	¹⁷⁶Ta	0+
¹⁷⁷W	74	103	176.946643(30)	132.4(20) min	β⁺	¹⁷⁷Ta	1/2−
¹⁷⁸W	74	104	177.945886(16)	21.6(3) d	EC	¹⁷⁸Ta	0+
^178mW	6572.7(3) keV			220(10) ns	IT	¹⁷⁸W	25+
¹⁷⁹W	74	105	178.947079(16)	37.05(16) min	β⁺	¹⁷⁹Ta	7/2−
^179m1W	221.91(3) keV			6.40(7) min	IT (99.71%)	¹⁷⁹W	1/2−
^179m1W	221.91(3) keV			6.40(7) min	β⁺ (0.29%)	¹⁷⁹Ta	1/2−
^179m2W	1631.90(8) keV			390(30) ns	IT	¹⁷⁹W	21/2+
^179m3W	3348.41(14) keV			750(80) ns	IT	¹⁷⁹W	35/2−
¹⁸⁰W^{[n 10]}	74	106	179.9467133(15)	1.59(5)×10¹⁸ y^[1]	α	¹⁷⁶Hf	0+	0.0012(1)
^180m1W	1529.05(4) keV			5.47(9) ms	IT	¹⁸⁰W	8−
^180m2W	3264.7(3) keV			2.33(19) μs	IT	¹⁸⁰W	14−
¹⁸¹W	74	107	180.9482187(16)	120.956(19) d	EC	¹⁸¹Ta	9/2+
^181m1W	365.55(13) keV			14.59(15) μs	IT	¹⁸¹W	5/2−
^181m2W	1653.0(3) keV			200(13) ns	IT	¹⁸¹W	21/2+
¹⁸²W	74	108	181.94820564(80)	Observationally Stable^{[n 11]}			0+	0.2650(16)
^182mW	2230.65(14) keV			1.3(1) μs	IT	¹⁸²W	10+
¹⁸³W	74	109	182.95022442(80)	Observationally Stable^{[n 12]}			1/2−	0.1431(4)
^183mW	309.492(4) keV			5.30(8) s	IT	¹⁸³W	11/2+
¹⁸⁴W	74	110	183.95093318(79)	Observationally Stable^{[n 13]}			0+	0.3064(2)
^184m1W	1284.997(8) keV			8.33(18) μs	IT	¹⁸⁴W	5−
^184m2W	4127.7(5) keV			188(38) ns	IT	¹⁸⁴W	(14+)
¹⁸⁵W	74	111	184.95342121(79)	75.1(3) d	β⁻	¹⁸⁵Re	3/2−
^185mW	197.383(23) keV			1.597(4) min	IT	¹⁸⁵W	11/2+
¹⁸⁶W	74	112	185.9543651(13)	Observationally Stable^{[n 14]}			0+	0.2843(19)
^186m1W	1517.2(6) keV			18(1) μs	IT	¹⁸⁶W	7−
^186m2W	3542.8(21) keV			2.0(2) s	IT	¹⁸⁶W	16+
¹⁸⁷W	74	113	186.9571612(13)	23.809(25) h	β⁻	¹⁸⁷Re	3/2−
^187mW	410.06(4) keV			1.54(13) μs^[8]	IT	¹⁸⁷W	11/2+
¹⁸⁸W	74	114	187.9584883(33)	69.77(5) d	β⁻	¹⁸⁸Re	0+
^188mW	1926.7(8) keV			109.5(35) ns	IT	¹⁸⁸W	8−
¹⁸⁹W	74	115	188.96156(22)#	11.6(2) min	β⁻	¹⁸⁹Re	9/2−#
¹⁹⁰W	74	116	189.963104(38)	30.0(15) min	β⁻	¹⁹⁰Re	0+
^190m1W	1743.6(10) keV			111(17) ns	IT	¹⁹⁰W	8+
^190m2W	1840.6(14) keV			166(6) μs	IT	¹⁹⁰W	10−
¹⁹¹W	74	117	190.966531(45)	14# s [>300 ns]			3/2−#
^191mW	235(10)# keV			340(14) ns	IT	¹⁹¹W	9/2−#
¹⁹²W	74	118	191.96820(22)#	40# s [>300 ns]			0+
¹⁹³W	74	119	192.97188(22)#	30# s [>300 ns]			1/2−#
¹⁹⁴W	74	120	193.97380(32)#	20# s [>300 ns]			0+
¹⁹⁵W	74	121	194.97774(32)#	30# s [>160 ns]			3/2−#
¹⁹⁶W	74	122	195.97988(43)#	25# s [>300 ns]			0+
¹⁹⁷W	74	123	196.98404(43)#	1# s [>300 ns]			5/2−#
This table header & footer: view

^ ^mW – 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).
^ Bold half-life – nearly stable, half-life longer than age of universe.
^ ^a ^b # – Values marked # are not purely derived from experimental data, but at least partly from trends of neighboring nuclides (TNN).
^ Modes of decay:

α: Alpha decay

β⁺: Positron emission

EC: Electron capture

β⁻: Beta decay

IT: Isomeric transition
^ Bold italics symbol as daughter – Daughter product is nearly stable.
^ Bold symbol as daughter – Daughter product is stable.
^ ( ) spin value – Indicates spin with weak assignment arguments.
^ Primordial radionuclide
^ Believed to undergo α decay to ¹⁷⁸Hf with a half-life over 7.7×10²¹ y
^ Believed to undergo α decay to ¹⁷⁹Hf with a half-life over 6.70×10²⁰ y
^ Believed to undergo α decay to ¹⁸⁰Hf with a half-life over 8.9×10²¹ y
^ Believed to undergo α decay to ¹⁸²Hf or β⁻β⁻ decay to ¹⁸⁶Os with a half-life over 4.1×10¹⁸ y

References

^ ^a ^b ^c Münster, A.; Sivers, M. v.; Angloher, G.; Bento, A.; Bucci, C.; Canonica, L.; Erb, A.; Feilitzsch, F. v.; Gorla, P.; Gütlein, A.; Hauff, D.; Jochum, J.; Kraus, H.; Lanfranchi, J. -C.; Laubenstein, M.; Loebell, J.; Ortigoza, Y.; Petricca, F.; Potzel, W.; Pröbst, F.; Puimedon, J.; Reindl, F.; Roth, S.; Rottler, K.; Sailer, C.; Schäffner, K.; Schieck, J.; Scholl, S.; Schönert, S.; Seidel, W.; Stodolsky, L.; Strandhagen, C.; Strauss, R.; Tanzke, A.; Uffinger, M.; Ulrich, A.; Usherov, I.; Wawoczny, S.; Willers, M.; Wüstrich, M.; Zöller, A. (May 2014). "Radiopurity of CaWO₄ crystals for direct dark matter search with CRESST and EURECA". Journal of Cosmology and Astroparticle Physics (05). arXiv:1403.5114. Bibcode:2014JCAP...05..018M. doi:10.1088/1475-7516/2014/05/018. 018.
^ "Standard Atomic Weights: Tungsten". CIAAW. 1991.
^ 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.
^ Wang, Meng; Huang, W.J.; Kondev, F.G.; Audi, G.; Naimi, S. (2021). "The AME 2020 atomic mass evaluation (II). Tables, graphs and references*". Chinese Physics C. 45 (3): 030003. doi:10.1088/1674-1137/abddaf.
^ ^a ^b ^c ^d 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.
^ Briscoe, A. D.; Page, R. D.; Uusitalo, J.; et al. (2023). "Decay spectroscopy at the two-proton drip line: Radioactivity of the new nuclides ¹⁶⁰Os and ¹⁵⁶W". Physics Letters B. 47 (138310). doi:10.1016/j.physletb.2023.138310. hdl:10272/23933.
^ Bianco, L.; Page, R. D.; Darby, I. G.; et al. (7 June 2010). "Discovery of ¹⁵⁷W and ¹⁶¹Os" (PDF). Physics Letters B. 690 (1): 15–18. Bibcode:2010PhLB..690...15B. doi:10.1016/j.physletb.2010.04.056. ISSN 0370-2693. S2CID 117121162. Retrieved 11 June 2023.
^ Chen, J. L.; Watanabe, H.; Walker, P. M.; et al. (2025). "Direct observation of β and γ decay from a high-spin long-lived isomer in ¹⁸⁷Ta". Physical Review C. 111 (014304). arXiv:2501.02848. doi:10.1103/PhysRevC.111.014304.