Isotopes of tungsten

Naturally occurring tungsten (atomic symbol W) consists of five 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.

Thirty-three 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 (t1/2 6.4 minutes).

Relative atomic mass: 183.84(1).

Table

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 y
  6. Believed to undergo α decay to 179Hf with a half-life over 8.0×1019 y
  7. Believed to undergo α decay to 180Hf with a half-life over 1.80×1020 y
  8. Believed to undergo α decay to 182Hf with a half-life over 4.1×1018 y

Notes

References

  1. "Universal Nuclide Chart". nucleonica. (registration required (help)).
Isotopes of tantalum Isotopes of tungsten Isotopes of rhenium
Table of nuclides
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