Natural
hafnium
Hafnium is a chemical element with the symbol Hf and atomic number 72. A lustrous, silvery gray, tetravalent transition metal, hafnium chemically resembles zirconium and is found in many zirconium minerals. Its existence was predicted by Dmitri M ...
(
72Hf) consists of five stable
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 (
176Hf,
177Hf,
178Hf,
179Hf, and
180Hf) and one very long-lived
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 ...
,
174Hf, with a
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 years.
[ In addition, there are 30 known synthetic radioisotopes, the most stable of which is 182Hf with a half-life of years. This ]extinct radionuclide
An extinct radionuclide is a radionuclide that was formed by nucleosynthesis before the formation of the Solar System, about 4.6 billion years ago, but has since decayed to virtually zero abundance and is no longer detectable as a primordial nuc ...
is used in hafnium–tungsten dating
Hafnium–tungsten dating is a geochronological radiometric dating method utilizing the radioactive decay system of hafnium-182 to tungsten-182. The half-life of the system is million years. Today hafnium-182 is an extinct radionuclide, but ...
to study the chronology of planetary differentiation
In planetary science, planetary differentiation is the process by which the chemical elements of a planetary body accumulate in different areas of that body, due to their physical or chemical behavior (e.g. density and chemical affinities). The ...
.
No other radioisotope has a half-life over 1.87 years. Most isotopes have half-lives under 1 minute. There are also 26 known nuclear isomer
A nuclear isomer is a metastable state of an atomic nucleus, in which one or more nucleons (protons or neutrons) occupy excited state, higher energy levels than in the ground state of the same nucleus. "Metastable" describes nuclei whose excited ...
s, the most stable of which is 178m2Hf with a half-life of 31 years. All isotopes of hafnium are either radioactive or 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 ...
, meaning that they are predicted to be radioactive but no actual decay has been observed.
List of isotopes
, -
, 153Hf
, style="text-align:right" , 72
, style="text-align:right" , 81
, 152.97069(54)#
, 400# ms 200 ns,
,
, 1/2+#
,
,
, -
, style="text-indent:1em" , 153mHf
, colspan="3" style="text-indent:2em" , 750(100)# keV
, 500# ms
,
,
, 11/2−#
,
,
, -
, rowspan=2, 154Hf
, rowspan=2 style="text-align:right" , 72
, rowspan=2 style="text-align:right" , 82
, rowspan=2, 153.96486(54)#
, rowspan=2, 2(1) s
, β+
, 154Lu
, rowspan=2, 0+
, rowspan=2,
, rowspan=2,
, -
, α (rare)
, 150Yb
, -
, rowspan=2, 155Hf
, rowspan=2 style="text-align:right" , 72
, rowspan=2 style="text-align:right" , 83
, rowspan=2, 154.96339(43)#
, rowspan=2, 890(120) ms
, β+
, 155Lu
, rowspan=2, 7/2−#
, rowspan=2,
, rowspan=2,
, -
, α (rare)
, 151Yb
, -
, rowspan=2, 156Hf
, rowspan=2 style="text-align:right" , 72
, rowspan=2 style="text-align:right" , 84
, rowspan=2, 155.95936(22)
, rowspan=2, 23(1) ms
, α (97%)
, 152Yb
, rowspan=2, 0+
, rowspan=2,
, rowspan=2,
, -
, β+ (3%)
, 156Lu
, -
, style="text-indent:1em" , 156mHf
, colspan="3" style="text-indent:2em" , 1959.0(10) keV
, 480(40) μs
,
,
, 8+
,
,
, -
, rowspan=2, 157Hf
, rowspan=2 style="text-align:right" , 72
, rowspan=2 style="text-align:right" , 85
, rowspan=2, 156.95840(21)#
, rowspan=2, 115(1) ms
, α (86%)
, 153Yb
, rowspan=2, 7/2−
, rowspan=2,
, rowspan=2,
, -
, β+ (14%)
, 157Lu
, -
, rowspan=2, 158Hf
, rowspan=2 style="text-align:right" , 72
, rowspan=2 style="text-align:right" , 86
, rowspan=2, 157.954799(19)
, rowspan=2, 2.84(7) s
, β+ (55%)
, 158Lu
, rowspan=2, 0+
, rowspan=2,
, rowspan=2,
, -
, α (45%)
, 154Yb
, -
, rowspan=2, 159Hf
, rowspan=2 style="text-align:right" , 72
, rowspan=2 style="text-align:right" , 87
, rowspan=2, 158.953995(18)
, rowspan=2, 5.20(10) s
, β+ (59%)
, 159Lu
, rowspan=2, 7/2−#
, rowspan=2,
, rowspan=2,
, -
, α (41%)
, 155Yb
, -
, rowspan=2, 160Hf
, rowspan=2 style="text-align:right" , 72
, rowspan=2 style="text-align:right" , 88
, rowspan=2, 159.950684(12)
, rowspan=2, 13.6(2) s
, β+ (99.3%)
, 160Lu
, rowspan=2, 0+
, rowspan=2,
, rowspan=2,
, -
, α (.7%)
, 156Yb
, -
, rowspan=2, 161Hf
, rowspan=2 style="text-align:right" , 72
, rowspan=2 style="text-align:right" , 89
, rowspan=2, 160.950275(24)
, rowspan=2, 18.2(5) s
, β+ (99.7%)
, 161Lu
, rowspan=2, 3/2−#
, rowspan=2,
, rowspan=2,
, -
, α (.3%)
, 157Yb
, -
, rowspan=2, 162Hf
, rowspan=2 style="text-align:right" , 72
, rowspan=2 style="text-align:right" , 90
, rowspan=2, 161.94721(1)
, rowspan=2, 39.4(9) s
, β+ (99.99%)
, 162Lu
, rowspan=2, 0+
, rowspan=2,
, rowspan=2,
, -
, α (.008%)
, 158Yb
, -
, rowspan=2, 163Hf
, rowspan=2 style="text-align:right" , 72
, rowspan=2 style="text-align:right" , 91
, rowspan=2, 162.94709(3)
, rowspan=2, 40.0(6) s
, β+
, 163Lu
, rowspan=2, 3/2−#
, rowspan=2,
, rowspan=2,
, -
, α (10−4%)
, 159Yb
, -
, 164Hf
, style="text-align:right" , 72
, style="text-align:right" , 92
, 163.944367(22)
, 111(8) s
, β+
, 164Lu
, 0+
,
,
, -
, 165Hf
, style="text-align:right" , 72
, style="text-align:right" , 93
, 164.94457(3)
, 76(4) s
, β+
, 165Lu
, (5/2−)
,
,
, -
, 166Hf
, style="text-align:right" , 72
, style="text-align:right" , 94
, 165.94218(3)
, 6.77(30) min
, β+
, 166Lu
, 0+
,
,
, -
, 167Hf
, style="text-align:right" , 72
, style="text-align:right" , 95
, 166.94260(3)
, 2.05(5) min
, β+
, 167Lu
, (5/2)−
,
,
, -
, 168Hf
, style="text-align:right" , 72
, style="text-align:right" , 96
, 167.94057(3)
, 25.95(20) min
, β+
, 168Lu
, 0+
,
,
, -
, 169Hf
, style="text-align:right" , 72
, style="text-align:right" , 97
, 168.94126(3)
, 3.24(4) min
, β+
, 169Lu
, (5/2)−
,
,
, -
, 170Hf
, style="text-align:right" , 72
, style="text-align:right" , 98
, 169.93961(3)
, 16.01(13) h
, EC
, 170Lu
, 0+
,
,
, -
, 171Hf
, style="text-align:right" , 72
, style="text-align:right" , 99
, 170.94049(3)
, 12.1(4) h
, β+
, 171Lu
, 7/2(+)
,
,
, -
, style="text-indent:1em" , 171mHf
, colspan="3" style="text-indent:2em" , 21.93(9) keV
, 29.5(9) s
, IT
, 171Hf
, 1/2(−)
,
,
, -
, 172Hf
, style="text-align:right" , 72
, style="text-align:right" , 100
, 171.939448(26)
, 1.87(3) y
, EC
, 172Lu
, 0+
,
,
, -
, style="text-indent:1em" , 172mHf
, colspan="3" style="text-indent:2em" , 2005.58(11) keV
, 163(3) ns
,
,
, (8−)
,
,
, -
, 173Hf
, style="text-align:right" , 72
, style="text-align:right" , 101
, 172.94051(3)
, 23.6(1) h
, β+
, 173Lu
, 1/2−
,
,
, -
, 174Hf[ 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" , 72
, style="text-align:right" , 102
, 173.940046(3)
, 7.0(12)×1016 y[
, α
, 170Yb
, 0+
, 0.0016(1)
, 0.001619–0.001621
, -
, style="text-indent:1em" , 174m1Hf
, colspan="3" style="text-indent:2em" , 1549.3 keV
, 138(4) ns
,
,
, (6+)
,
,
, -
, style="text-indent:1em" , 174m2Hf
, colspan="3" style="text-indent:2em" , 1797.5(20) keV
, 2.39(4) μs
,
,
, (8−)
,
,
, -
, style="text-indent:1em" , 174m3Hf
, colspan="3" style="text-indent:2em" , 3311.7 keV
, 3.7(2) μs
,
,
, (14+)
,
,
, -
, 175Hf
, style="text-align:right" , 72
, style="text-align:right" , 103
, 174.941509(3)
, 70(2) d
, β+
, 175Lu
, 5/2−
,
,
, -
, 176Hf][Used in lutetium-hafnium dating]
, style="text-align:right" , 72
, style="text-align:right" , 104
, 175.9414086(24)
, 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 172Yb]
, 0+
, 0.0526(7)
, 0.05206–0.05271
, -
, 177Hf
, style="text-align:right" , 72
, style="text-align:right" , 105
, 176.9432207(23)
, colspan=3 align=center, Observationally Stable[Believed to undergo α decay to 173Yb]
, 7/2−
, 0.1860(9)
, 0.18593–0.18606
, -
, style="text-indent:1em" , 177m1Hf
, colspan="3" style="text-indent:2em" , 1315.4504(8) keV
, 1.09(5) s
,
,
, 23/2+
,
,
, -
, style="text-indent:1em" , 177m2Hf
, colspan="3" style="text-indent:2em" , 1342.38(20) keV
, 55.9(12) μs
,
,
, (19/2−)
,
,
, -
, style="text-indent:1em" , 177m3Hf
, colspan="3" style="text-indent:2em" , 2740.02(15) keV
, 51.4(5) min
,
,
, 37/2−
,
,
, -
, 178Hf
, style="text-align:right" , 72
, style="text-align:right" , 106
, 177.9436988(23)
, colspan=3 align=center, Observationally Stable[Believed to undergo α decay to 174Yb]
, 0+
, 0.2728(7)
, 0.27278–0.27297
, -
, style="text-indent:1em" , 178m1Hf
, colspan="3" style="text-indent:2em" , 1147.423(5) keV
, 4.0(2) s
,
,
, 8−
,
,
, -
, style="text-indent:1em" , 178m2Hf
, colspan="3" style="text-indent:2em" , 2445.69(11) keV
, 31(1) y
,
,
, 16+
,
,
, -
, style="text-indent:1em" , 178m3Hf
, colspan="3" style="text-indent:2em" , 2573.5(5) keV
, 68(2) μs
,
,
, (14−)
,
,
, -
, 179Hf
, style="text-align:right" , 72
, style="text-align:right" , 107
, 178.9458161(23)
, colspan=3 align=center, Observationally Stable[Believed to undergo α decay to 175Yb]
, 9/2+
, 0.1362(2)
, 0.13619–0.1363
, -
, style="text-indent:1em" , 179m1Hf
, colspan="3" style="text-indent:2em" , 375.0367(25) keV
, 18.67(4) s
,
,
, 1/2−
,
,
, -
, style="text-indent:1em" , 179m2Hf
, colspan="3" style="text-indent:2em" , 1105.84(19) keV
, 25.05(25) d
,
,
, 25/2−
,
,
, -
, 180Hf
, style="text-align:right" , 72
, style="text-align:right" , 108
, 179.9465500(23)
, colspan=3 align=center, Observationally Stable[Believed to undergo α decay to 176Yb]
, 0+
, 0.3508(16)
, 0.35076–0.351
, -
, style="text-indent:1em" , 180m1Hf
, colspan="3" style="text-indent:2em" , 1141.48(4) keV
, 5.47(4) h
,
,
, 8−
,
,
, -
, style="text-indent:1em" , 180m2Hf
, colspan="3" style="text-indent:2em" , 1374.15(4) keV
, 0.57(2) μs
,
,
, (4−)
,
,
, -
, style="text-indent:1em" , 180m3Hf
, colspan="3" style="text-indent:2em" , 2425.8(10) keV
, 15(5) μs
,
,
, (10+)
,
,
, -
, style="text-indent:1em" , 180m4Hf
, colspan="3" style="text-indent:2em" , 2486.3(9) keV
, 10(1) μs
,
,
, 12+
,
,
, -
, style="text-indent:1em" , 180m5Hf
, colspan="3" style="text-indent:2em" , 2538.3(12) keV
, >10 μs
,
,
, (14+)
,
,
, -
, style="text-indent:1em" , 180m6Hf
, colspan="3" style="text-indent:2em" , 3599.3(18) keV
, 90(10) μs
,
,
, (18−)
,
,
, -
, 181Hf
, style="text-align:right" , 72
, style="text-align:right" , 109
, 180.9491012(23)
, 42.39(6) d
, β−
, 181Ta
, 1/2−
,
,
, -
, style="text-indent:1em" , 181m1Hf
, colspan="3" style="text-indent:2em" , 595(3) keV
, 80(5) μs
,
,
, (9/2+)
,
,
, -
, style="text-indent:1em" , 181m2Hf
, colspan="3" style="text-indent:2em" , 1040(10) keV
, ~100 μs
,
,
, (17/2+)
,
,
, -
, style="text-indent:1em" , 181m3Hf
, colspan="3" style="text-indent:2em" , 1738(10) keV
, 1.5(5) ms
,
,
, (27/2−)
,
,
, -
, 182Hf
, style="text-align:right" , 72
, style="text-align:right" , 110
, 181.950554(7)
, 8.90(9)×106 y
, β−
, 182Ta
, 0+
,
,
, -
, rowspan=2 style="text-indent:1em" , 182mHf
, rowspan=2 colspan="3" style="text-indent:2em" , 1172.88(18) keV
, rowspan=2, 61.5(15) min
, β− (58%)
, 182Ta
, rowspan=2, 8−
, rowspan=2,
, rowspan=2,
, -
, IT (42%)
, 182Hf
, -
, 183Hf
, style="text-align:right" , 72
, style="text-align:right" , 111
, 182.95353(3)
, 1.067(17) h
, β−
, 183Ta
, (3/2−)
,
,
, -
, 184Hf
, style="text-align:right" , 72
, style="text-align:right" , 112
, 183.95545(4)
, 4.12(5) h
, β−
, 184Ta
, 0+
,
,
, -
, style="text-indent:1em" , 184mHf
, colspan="3" style="text-indent:2em" , 1272.4(4) keV
, 48(10) s
, β−
, 184Ta
, 8−
,
,
, -
, 185Hf
, style="text-align:right" , 72
, style="text-align:right" , 113
, 184.95882(21)#
, 3.5(6) min
, β−
, 185Ta
, 3/2−#
,
,
, -
, 186Hf
, style="text-align:right" , 72
, style="text-align:right" , 114
, 185.96089(32)#
, 2.6(12) min
, β−
, 186Ta
, 0+
,
,
, -
, 187Hf
, style="text-align:right" , 72
, style="text-align:right" , 115
, 186.96459(43)#
, 30# s 300 ns,
,
,
,
,
, -
, 188Hf
, style="text-align:right" , 72
, style="text-align:right" , 116
, 187.96685(54)#
, 20# 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
Hafnium
Hafnium
Hafnium is a chemical element with the symbol Hf and atomic number 72. A lustrous, silvery gray, tetravalent transition metal, hafnium chemically resembles zirconium and is found in many zirconium minerals. Its existence was predicted by Dmitri M ...