Naturally occurring tungsten (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
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 a | 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+ |
Isotopes of tantalum | Isotopes of tungsten | Isotopes of rhenium |
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