Isotopes of tungsten

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 1.8 ± 0.2 exayears (10¹⁸ years). 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 can decay into isotopes of element 72 (hafnium) 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

Isotopes of tungsten (₇₄W)

Main isotopes Decay abun­dance half-life (t1/2) mode pro­duct 180W 0.120% 1.8×1018 y α 176Hf 181W synth 121.2 d ε 181Ta 182W 26.5% stable 183W 14.3% stable 184W 30.6% stable 185W synth 75.1 d β− 185Re 186W 28.4% stable 188W synth 69.78 d β− 188Re
Standard atomic weight Ar°(W)
	183.84±0.01[1] 183.84±0.01 (abridged)[2]
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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 11 meta states with mass numbers of 158, 179, with 3, 180, with 2, 183, 185, 186, with 2, and 190, the most stable being ^179m1W (t_1/2 6.4 minutes).

List of isotopes

Nuclide [n 1]	Z	N	Isotopic mass (Da) [n 2][n 3]	Half-life [n 4][n 5]	Decay mode [n 6]	Daughter isotope [n 7][n 8]	Spin and parity [n 9][n 5]	Natural abundance (mole fraction)
	Excitation energy							Normal proportion	Range of variation
156W[3]	74	82		157+57 −34 ms	β+	156Ta	0+
157W[4]	74	83		275(40) ms	β+	157Ta	(7/2−)
158W	74	84	157.97456(54)#	1.37(17) ms	α	154Hf	0+
158mW	1889(8) keV			143(19) μs	α	154Hf	8+
159W	74	85	158.97292(43)#	8.2(7) ms	α (82%)	155Hf	7/2−#
					β+ (18%)	159Ta
160W	74	86	159.96848(22)	90(5) ms	α (87%)	156Hf	0+
					β+ (14%)	160Ta
161W	74	87	160.96736(21)#	409(16) ms	α (73%)	157Hf	7/2−#
					β+ (23%)	161Ta
162W	74	88	161.963497(19)	1.36(7) s	β+ (53%)	162Ta	0+
					α (47%)	158Hf
163W	74	89	162.96252(6)	2.8(2) s	β+ (59%)	163Ta	3/2−#
					α (41%)	159Hf
164W	74	90	163.958954(13)	6.3(2) s	β+ (97.4%)	164Ta	0+
					α (2.6%)	160Hf
165W	74	91	164.958280(27)	5.1(5) s	β+ (99.8%)	165Ta	3/2−#
					α (.2%)	161Hf
166W	74	92	165.955027(11)	19.2(6) s	β+ (99.96%)	166Ta	0+
					α (.035%)	162Hf
167W	74	93	166.954816(21)	19.9(5) s	β+ (>99.9%)	167Ta	3/2−#
					α (<.1%)	163Hf
168W	74	94	167.951808(17)	51(2) s	β+ (99.99%)	168Ta	0+
					α (.0319%)	164Hf
169W	74	95	168.951779(17)	76(6) s	β+	169Ta	(5/2−)
170W	74	96	169.949228(16)	2.42(4) min	β+(99%)	170Ta	0+
					α (1%)	166Hf
171W	74	97	170.94945(3)	2.38(4) min	β+	171Ta	(5/2−)
172W	74	98	171.94729(3)	6.6(9) min	β+	172Ta	0+
173W	74	99	172.94769(3)	7.6(2) min	β+	173Ta	5/2−
174W	74	100	173.94608(3)	33.2(21) min	β+	174Ta	0+
175W	74	101	174.94672(3)	35.2(6) min	β+	175Ta	(1/2−)
176W	74	102	175.94563(3)	2.5(1) h	EC	176Ta	0+
177W	74	103	176.94664(3)	132(2) min	β+	177Ta	1/2−
178W	74	104	177.945876(16)	21.6(3) d	EC	178Ta	0+
179W	74	105	178.947070(17)	37.05(16) min	β+	179Ta	(7/2)−
179m1W	221.926(8) keV			6.40(7) min	IT (99.72%)	179W	(1/2)−
					β+ (.28%)	179Ta
179m2W	1631.90(8) keV			390(30) ns			(21/2+)
179m3W	3348.45(16) keV			750(80) ns			(35/2−)
180W[n 10]	74	106	179.946704(4)	1.8(0.2)×1018 y	α	176Hf	0+	0.0012(1)
180m1W	1529.04(3) keV			5.47(9) ms	IT	180W	8−
180m2W	3264.56(21) keV			2.33(19) μs			14−
181W	74	107	180.948197(5)	121.2(2) d	EC	181Ta	9/2+
182W	74	108	181.9482042(9)	Observationally Stable[n 11]			0+	0.2650(16)
183W	74	109	182.9502230(9)	Observationally Stable[n 12]			1/2−	0.1431(4)
183mW	309.493(3) keV			5.2(3) s	IT	183W	11/2+
184W	74	110	183.9509312(9)	Observationally Stable[n 13]			0+	0.3064(2)
185W	74	111	184.9534193(10)	75.1(3) d	β−	185Re	3/2−
185mW	197.43(5) keV			1.597(4) min	IT	185W	11/2+
186W	74	112	185.9543641(19)	Observationally Stable[n 14]			0+	0.2843(19)
186m1W	1517.2(6) keV			18(1) μs			(7−)
186m2W	3542.8(21) keV			>3 ms			(16+)
187W	74	113	186.9571605(19)	23.72(6) h	β−	187Re	3/2−
188W	74	114	187.958489(4)	69.78(5) d	β−	188Re	0+
189W	74	115	188.96191(21)	11.6(3) min	β−	189Re	(3/2−)
190W	74	116	189.96318(18)	30.0(15) min	β−	190Re	0+
190mW	2381(5) keV			<3.1 ms			(10−)
191W	74	117	190.96660(21)#	20# s [>300 ns]			3/2−#
192W	74	118	191.96817(64)#	10# s [>300 ns]			0+
This table header & footer: view

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

   EC:	Electron capture
   IT:	Isomeric transition

7. Bold italics symbol as daughter – Daughter product is nearly stable.
8. Bold symbol as daughter – Daughter product is stable.
9. ( ) spin value – Indicates spin with weak assignment arguments.
10. Primordial radionuclide
11. Believed to undergo α decay to ¹⁷⁸Hf with a half-life over 7.7×10²¹ y
12. Believed to undergo α decay to ¹⁷⁹Hf with a half-life over 4.1×10²¹ y
13. Believed to undergo α decay to ¹⁸⁰Hf with a half-life over 8.9×10²¹ y
14. Believed to undergo α decay to ¹⁸²Hf or β⁻β⁻ decay to ¹⁸⁶Os with a half-life over 8.2×10²¹ y

References

1. "Standard Atomic Weights: Tungsten". CIAAW. 1991.
2. 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.
3. 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.
4. 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.

• 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
• 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
  • 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.