Naturally occurring
tungsten
Tungsten, or wolfram, is a chemical element with the symbol W and atomic number 74. Tungsten is a rare metal found naturally on Earth almost exclusively as compounds with other elements. It was identified as a new element in 1781 and first isolat ...
(
74W) consists of five
isotope
Isotopes are two or more types of atoms that have the same atomic number (number of protons in their nuclei) and position in the periodic table (and hence belong to the same chemical element), and that differ in nucleon numbers (mass numbers) ...
s. Four are considered
stable
A stable is a building in which livestock, especially horses, are kept. It most commonly means a building that is divided into separate stalls for individual animals and livestock. There are many different types of stables in use today; the ...
(
182W,
183W,
184W, and
186W) and one is slightly
radioactive
Radioactive decay (also known as nuclear decay, radioactivity, radioactive disintegration, or nuclear disintegration) is the process by which an unstable atomic nucleus loses energy by radiation. A material containing unstable nuclei is consid ...
,
180W, with an extremely long
half-life
Half-life (symbol ) is the time required for a quantity (of substance) to reduce to half of its initial value. The term is commonly used in nuclear physics to describe how quickly unstable atoms undergo radioactive decay or how long stable ato ...
of 1.8 ± 0.2
exayears (10
18 years). On average, two
alpha decay
Alpha decay or α-decay is a type of radioactive decay in which an atomic nucleus emits an alpha particle (helium nucleus) and thereby transforms or 'decays' into a different atomic nucleus, with a mass number that is reduced by four and an atom ...
s of
180W occur per gram of natural tungsten per year, so for most practical purposes, tungsten 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
Stable nuclides are nuclides that are not radioactive and so (unlike radionuclides) do not spontaneously undergo radioactive decay. When such nuclides are referred to in relation to specific elements, they are usually termed stable isotopes.
Th ...
), and lower bounds for their half lives have been established:
:
182W, t
1/2 > 7.7×10
21 years
:
183W, t
1/2 > 4.1×10
21 years
:
184W, t
1/2 > 8.9×10
21 years
:
186W, t
1/2 > 8.2×10
21 years
Thirty-three artificial
radioisotope
A radionuclide (radioactive nuclide, radioisotope or radioactive isotope) is a nuclide that has excess nuclear energy, making it unstable. This excess energy can be used in one of three ways: emitted from the nucleus as gamma radiation; transferr ...
s 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
Radioactive decay (also known as nuclear decay, radioactivity, radioactive disintegration, or nuclear disintegration) is the process by which an unstable atomic nucleus loses energy by radiation. A material containing unstable nuclei is consid ...
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 state
A nuclear isomer is a metastable state of an atomic nucleus, in which one or more nucleons (protons or neutrons) occupy higher energy levels than in the ground state of the same nucleus. "Metastable" describes nuclei whose excited states have ha ...
s 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
, -
,
158W
, style="text-align:right" , 74
, style="text-align:right" , 84
, 157.97456(54)#
, 1.37(17) ms
,
α
,
154Hf
, 0+
,
,
, -
, style="text-indent:1em" ,
158mW
, colspan="3" style="text-indent:2em" , 1889(8) keV
, 143(19) μs
,
,
, 8+
,
,
, -
, rowspan=2,
159W
, rowspan=2 style="text-align:right" , 74
, rowspan=2 style="text-align:right" , 85
, rowspan=2, 158.97292(43)#
, rowspan=2, 8.2(7) ms
, α (82%)
,
155Hf
, rowspan=2, 7/2−#
, rowspan=2,
, rowspan=2,
, -
,
β+ (18%)
,
159Ta
, -
, rowspan=2,
160W
, rowspan=2 style="text-align:right" , 74
, rowspan=2 style="text-align:right" , 86
, rowspan=2, 159.96848(22)
, rowspan=2, 90(5) ms
, α (87%)
,
156Hf
, rowspan=2, 0+
, rowspan=2,
, rowspan=2,
, -
, β
+ (14%)
,
160Ta
, -
, rowspan=2,
161W
, rowspan=2 style="text-align:right" , 74
, rowspan=2 style="text-align:right" , 87
, rowspan=2, 160.96736(21)#
, rowspan=2, 409(16) ms
, α (73%)
,
157Hf
, rowspan=2, 7/2−#
, rowspan=2,
, rowspan=2,
, -
, β
+ (23%)
,
161Ta
, -
, rowspan=2,
162W
, rowspan=2 style="text-align:right" , 74
, rowspan=2 style="text-align:right" , 88
, rowspan=2, 161.963497(19)
, rowspan=2, 1.36(7) s
, β
+ (53%)
,
162Ta
, rowspan=2, 0+
, rowspan=2,
, rowspan=2,
, -
, α (47%)
,
158Hf
, -
, rowspan=2,
163W
, rowspan=2 style="text-align:right" , 74
, rowspan=2 style="text-align:right" , 89
, rowspan=2, 162.96252(6)
, rowspan=2, 2.8(2) s
, β
+ (59%)
,
163Ta
, rowspan=2, 3/2−#
, rowspan=2,
, rowspan=2,
, -
, α (41%)
,
159Hf
, -
, rowspan=2,
164W
, rowspan=2 style="text-align:right" , 74
, rowspan=2 style="text-align:right" , 90
, rowspan=2, 163.958954(13)
, rowspan=2, 6.3(2) s
, β
+ (97.4%)
,
164Ta
, rowspan=2, 0+
, rowspan=2,
, rowspan=2,
, -
, α (2.6%)
,
160Hf
, -
, rowspan=2,
165W
, rowspan=2 style="text-align:right" , 74
, rowspan=2 style="text-align:right" , 91
, rowspan=2, 164.958280(27)
, rowspan=2, 5.1(5) s
, β
+ (99.8%)
,
165Ta
, rowspan=2, 3/2−#
, rowspan=2,
, rowspan=2,
, -
, α (.2%)
,
161Hf
, -
, rowspan=2,
166W
, rowspan=2 style="text-align:right" , 74
, rowspan=2 style="text-align:right" , 92
, rowspan=2, 165.955027(11)
, rowspan=2, 19.2(6) s
, β
+ (99.96%)
,
166Ta
, rowspan=2, 0+
, rowspan=2,
, rowspan=2,
, -
, α (.035%)
,
162Hf
, -
, rowspan=2,
167W
, rowspan=2 style="text-align:right" , 74
, rowspan=2 style="text-align:right" , 93
, rowspan=2, 166.954816(21)
, rowspan=2, 19.9(5) s
, β
+ (>99.9%)
,
167Ta
, rowspan=2, 3/2−#
, rowspan=2,
, rowspan=2,
, -
, α (<.1%)
,
163Hf
, -
, rowspan=2,
168W
, rowspan=2 style="text-align:right" , 74
, rowspan=2 style="text-align:right" , 94
, rowspan=2, 167.951808(17)
, rowspan=2, 51(2) s
, β
+ (99.99%)
,
168Ta
, rowspan=2, 0+
, rowspan=2,
, rowspan=2,
, -
, α (.0319%)
,
164Hf
, -
,
169W
, style="text-align:right" , 74
, style="text-align:right" , 95
, 168.951779(17)
, 76(6) s
, β
+
,
169Ta
, (5/2−)
,
,
, -
, rowspan=2,
170W
, rowspan=2 style="text-align:right" , 74
, rowspan=2 style="text-align:right" , 96
, rowspan=2, 169.949228(16)
, rowspan=2, 2.42(4) min
, β
+(99%)
,
170Ta
, rowspan=2, 0+
, rowspan=2,
, rowspan=2,
, -
, α (1%)
,
166Hf
, -
,
171W
, style="text-align:right" , 74
, style="text-align:right" , 97
, 170.94945(3)
, 2.38(4) min
, β
+
,
171Ta
, (5/2−)
,
,
, -
,
172W
, style="text-align:right" , 74
, style="text-align:right" , 98
, 171.94729(3)
, 6.6(9) min
, β
+
,
172Ta
, 0+
,
,
, -
,
173W
, style="text-align:right" , 74
, style="text-align:right" , 99
, 172.94769(3)
, 7.6(2) min
, β
+
,
173Ta
, 5/2−
,
,
, -
,
174W
, style="text-align:right" , 74
, style="text-align:right" , 100
, 173.94608(3)
, 33.2(21) min
, β
+
,
174Ta
, 0+
,
,
, -
,
175W
, style="text-align:right" , 74
, style="text-align:right" , 101
, 174.94672(3)
, 35.2(6) min
, β
+
,
175Ta
, (1/2−)
,
,
, -
,
176W
, style="text-align:right" , 74
, style="text-align:right" , 102
, 175.94563(3)
, 2.5(1) h
,
EC
,
176Ta
, 0+
,
,
, -
,
177W
, style="text-align:right" , 74
, style="text-align:right" , 103
, 176.94664(3)
, 132(2) min
, β
+
,
177Ta
, 1/2−
,
,
, -
,
178W
, style="text-align:right" , 74
, style="text-align:right" , 104
, 177.945876(16)
, 21.6(3) d
, EC
,
178Ta
, 0+
,
,
, -
,
179W
, style="text-align:right" , 74
, style="text-align:right" , 105
, 178.947070(17)
, 37.05(16) min
, β
+
,
179Ta
, (7/2)−
,
,
, -
, rowspan=2 style="text-indent:1em" ,
179m1W
, rowspan=2 colspan="3" style="text-indent:2em" , 221.926(8) keV
, rowspan=2, 6.40(7) min
,
IT (99.72%)
,
179W
, rowspan=2, (1/2)−
, rowspan=2,
, rowspan=2,
, -
, β
+ (.28%)
,
179Ta
, -
, style="text-indent:1em" ,
179m2W
, colspan="3" style="text-indent:2em" , 1631.90(8) keV
, 390(30) ns
,
,
, (21/2+)
,
,
, -
, style="text-indent:1em" ,
179m3W
, colspan="3" style="text-indent:2em" , 3348.45(16) keV
, 750(80) ns
,
,
, (35/2−)
,
,
, -
,
180W
[ Primordial ]radionuclide
A radionuclide (radioactive nuclide, radioisotope or radioactive isotope) is a nuclide that has excess nuclear energy, making it unstable. This excess energy can be used in one of three ways: emitted from the nucleus as gamma radiation; transfer ...
, style="text-align:right" , 74
, style="text-align:right" , 106
, 179.946704(4)
, 1.8(0.2)×10
18 y
, α
,
176Hf
, 0+
, 0.0012(1)
,
, -
, style="text-indent:1em" ,
180m1W
, colspan="3" style="text-indent:2em" , 1529.04(3) keV
, 5.47(9) ms
, IT
, ''
180W''
, 8−
,
,
, -
, style="text-indent:1em" ,
180m2W
, colspan="3" style="text-indent:2em" , 3264.56(21) keV
, 2.33(19) μs
,
,
, 14−
,
,
, -
,
181W
, style="text-align:right" , 74
, style="text-align:right" , 107
, 180.948197(5)
, 121.2(2) d
, EC
,
181Ta
, 9/2+
,
,
, -
,
182W
, style="text-align:right" , 74
, style="text-align:right" , 108
, 181.9482042(9)
, colspan=3 align=center,
Observationally Stable
Stable nuclides are nuclides that are not radioactive and so (unlike radionuclides) do not spontaneously undergo radioactive decay. When such nuclides are referred to in relation to specific elements, they are usually termed stable isotopes.
Th ...
[Believed to undergo α decay to 178Hf with a half-life over 7.7×1021 y]
, 0+
, 0.2650(16)
,
, -
,
183W
, style="text-align:right" , 74
, style="text-align:right" , 109
, 182.9502230(9)
, colspan=3 align=center, Observationally Stable
[Believed to undergo α decay to 179Hf with a half-life over 4.1×1021 y]
, 1/2−
, 0.1431(4)
,
, -
, style="text-indent:1em" ,
183mW
, colspan="3" style="text-indent:2em" , 309.493(3) keV
, 5.2(3) s
, IT
,
183W
, 11/2+
,
,
, -
,
184W
, style="text-align:right" , 74
, style="text-align:right" , 110
, 183.9509312(9)
, colspan=3 align=center, Observationally Stable
[Believed to undergo α decay to 180Hf with a half-life over 8.9×1021 y]
, 0+
, 0.3064(2)
,
, -
,
185W
, style="text-align:right" , 74
, style="text-align:right" , 111
, 184.9534193(10)
, 75.1(3) d
, β
−
,
185Re
, 3/2−
,
,
, -
, style="text-indent:1em" ,
185mW
, colspan="3" style="text-indent:2em" , 197.43(5) keV
, 1.597(4) min
, IT
,
185W
, 11/2+
,
,
, -
,
186W
, style="text-align:right" , 74
, style="text-align:right" , 112
, 185.9543641(19)
, colspan=3 align=center, Observationally Stable
[Believed to undergo α decay to 182Hf or β−β− decay to ''186Os'' with a half-life over 8.2×1021 y]
, 0+
, 0.2843(19)
,
, -
, style="text-indent:1em" ,
186m1W
, colspan="3" style="text-indent:2em" , 1517.2(6) keV
, 18(1) μs
,
,
, (7−)
,
,
, -
, style="text-indent:1em" ,
186m2W
, colspan="3" style="text-indent:2em" , 3542.8(21) keV
, >3 ms
,
,
, (16+)
,
,
, -
,
187W
, style="text-align:right" , 74
, style="text-align:right" , 113
, 186.9571605(19)
, 23.72(6) h
, β
−
, ''
187Re''
, 3/2−
,
,
, -
,
188W
, style="text-align:right" , 74
, style="text-align:right" , 114
, 187.958489(4)
, 69.78(5) d
, β
−
,
188Re
, 0+
,
,
, -
,
189W
, style="text-align:right" , 74
, style="text-align:right" , 115
, 188.96191(21)
, 11.6(3) min
, β
−
,
189Re
, (3/2−)
,
,
, -
,
190W
, style="text-align:right" , 74
, style="text-align:right" , 116
, 189.96318(18)
, 30.0(15) min
, β
−
,
190Re
, 0+
,
,
, -
, style="text-indent:1em" ,
190mW
, colspan="3" style="text-indent:2em" , 2381(5) keV
, <3.1 ms
,
,
, (10−)
,
,
, -
,
191W
, style="text-align:right" , 74
, style="text-align:right" , 117
, 190.96660(21)#
, 20# s
300 ns,
,
, 3/2−#
,
,
, -
,
192W
, style="text-align:right" , 74
, style="text-align:right" , 118
, 191.96817(64)#
, 10# s
300 ns,
,
, 0+
,
,
References
* Isotope masses from:
**
* Isotopic compositions and standard atomic masses from:
**
**
* Half-life, spin, and isomer data selected from the following sources.
**
**
**
{{Navbox element isotopes
Tungsten
Tungsten
Tungsten, or wolfram, is a chemical element with the symbol W and atomic number 74. Tungsten is a rare metal found naturally on Earth almost exclusively as compounds with other elements. It was identified as a new element in 1781 and first isolat ...