Isotopes of tungsten

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Naturally occurring tungsten (atomic symbol W) consists of four stable isotopes (182W, 183W, 184W, and 186W) and one isotope, 180W, with an extremely long half-life of 1.8 ± 0.2 Ea (1018 years). On average, two alpha decays of 180W occur per gram of natural tungsten per year.

33 artificial radioisotopes of tungsten have been characterized with mass numbers ranging from 157 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 (t½ 6.4 minutes).

Standard atomic mass: 183.84(1) u

Table[edit]

nuclide
symbol
Z(p) N(n)  
isotopic mass (u)
 
half-life[n 1] decay
mode(s)[1][n 2]
daughter
isotope(s)[n 3]
nuclear
spin
representative
isotopic
composition
(mole fraction)
range of natural
variation
(mole fraction)
excitation energy
158W 74 84 157.97456(54)# 1.37(17) ms α 154Hf 0+
158mW 1889(8) keV 143(19) µs 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 4] 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 5] 0+ 0.2650(16)
183W 74 109 182.9502230(9) Observationally Stable [n 6] 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 7] 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 8] 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+
  1. ^ Bold for isotopes with half-lives longer than the age of the universe (nearly stable)
  2. ^ Abbreviations:
    EC: Electron capture
    IT: Isomeric transition
  3. ^ Bold for stable isotopes, bold italics for nearly-stable isotopes (half-life longer than the age of the universe)
  4. ^ Primordial radionuclide
  5. ^ Believed to undergo α decay to 178Hf with a half-life over 1.70×1020 years
  6. ^ Believed to undergo α decay to 179Hf with a half-life over 80×1018 years
  7. ^ Believed to undergo α decay to 180Hf with a half-life over 180×1018 years
  8. ^ Believed to undergo α decay to 182Hf with a half-life over 4.1×1018 years

Notes[edit]

  • 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[edit]


Isotopes of tantalum Isotopes of tungsten Isotopes of rhenium
Table of nuclides