Natural

hafnium Hafnium is a chemical element; it has 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 Dm ...

(₇₂Hf) consists of five observationally stable

isotope Isotopes are distinct nuclear species (or ''nuclides'') of the same chemical element. They have the same atomic number (number of protons in their Atomic nucleus, nuclei) and position in the periodic table (and hence belong to the same chemica ...

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 numbers of either neutrons or protons, giving it excess nuclear energy, and making it unstable. This excess energy can be used in one of three ...

, ¹⁷⁴Hf, with a

half-life Half-life is a mathematical and scientific description of exponential or gradual decay. Half-life, half life or halflife may also refer to: Film * Half-Life (film), ''Half-Life'' (film), a 2008 independent film by Jennifer Phang * ''Half Life: ...

of years. In addition, there are 34 known

synthetic radioisotope A synthetic radioisotope is a radionuclide that is not found in nature: no natural process or mechanism exists which produces it, or it is so unstable that it decays away in a very short period of time. Frédéric Joliot-Curie and Irène Joliot-Cu ...

s, 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 nu ...

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, bu ...

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 pr ...

. No other radioisotope has a half-life over 1.87 years. Most isotopes have half-lives under 1 minute. There are also at least 27

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 levels (higher energy levels). "Metastable" describes nuclei whose excited states have Half-life, half-lives of ...

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 isotopes of a chemical element whose nucleons are in a configuration that does not permit them the surplus energy required to produce a radioactive emission. The nuclei of such isotopes are not radioactive and unlike radionuc ...

, meaning that they are predicted to be radioactive but no actual decay has been observed.

List of isotopes

, -id=Hafnium-153 , ¹⁵³Hf , style="text-align:right" , 72 , style="text-align:right" , 81 , 152.97069(32)# , 400# ms
200 ns, , , 1/2+# , , , -id=Hafnium-154 , rowspan=2, ¹⁵⁴Hf , rowspan=2 style="text-align:right" , 72 , rowspan=2 style="text-align:right" , 82 , rowspan=2, 153.96486(32)# , rowspan=2, 2(1) s , β⁺ , ¹⁵⁴Lu , rowspan=2, 0+ , rowspan=2, , rowspan=2, , - , α (rare) , ¹⁵⁰Yb , -id=Hafnium-154m , style="text-indent:1em" , ^154mHf , colspan="3" style="text-indent:2em" , 2721(50)# keV , 9(4) μs , IT , ¹⁵⁴Hf , (10+) , , , -id=Hafnium-155 , ¹⁵⁵Hf , style="text-align:right" , 72 , style="text-align:right" , 83 , 154.96317(32)# , 843(30) ms , β⁺ , ¹⁵⁵Lu , 7/2−# , , , -id=Hafnium-156 , ¹⁵⁶Hf , style="text-align:right" , 72 , style="text-align:right" , 84 , 155.95940(16) , 23(1) ms , α , ¹⁵²Yb , 0+ , , , -id=Hafnium-156m , style="text-indent:1em" , ^156mHf , colspan="3" style="text-indent:2em" , 1958.8(10) keV , 480(40) μs , α , ¹⁵²Yb , (8+) , , , -id=Hafnium-157 , rowspan=2, ¹⁵⁷Hf , rowspan=2 style="text-align:right" , 72 , rowspan=2 style="text-align:right" , 85 , rowspan=2, 156.95829(22)# , rowspan=2, 115(1) ms , α (94%) , ¹⁵³Yb , rowspan=2, 7/2− , rowspan=2, , rowspan=2, , - , β⁺ (6%) , ¹⁵⁷Lu , -id=Hafnium-158 , rowspan=2, ¹⁵⁸Hf , rowspan=2 style="text-align:right" , 72 , rowspan=2 style="text-align:right" , 86 , rowspan=2, 157.954801(19) , rowspan=2, 2.85(7) s , β⁺ (55.7%) , ¹⁵⁸Lu , rowspan=2, 0+ , rowspan=2, , rowspan=2, , - , α (44.3%) , ¹⁵⁴Yb , -id=Hafnium-159 , rowspan=2, ¹⁵⁹Hf , rowspan=2 style="text-align:right" , 72 , rowspan=2 style="text-align:right" , 87 , rowspan=2, 158.953996(18) , rowspan=2, 5.20(10) s , β⁺ (65%) , ¹⁵⁹Lu , rowspan=2, 7/2− , rowspan=2, , rowspan=2, , - , α (35%) , ¹⁵⁵Yb , -id=Hafnium-160 , rowspan=2, ¹⁶⁰Hf , rowspan=2 style="text-align:right" , 72 , rowspan=2 style="text-align:right" , 88 , rowspan=2, 159.950683(10) , rowspan=2, 13.6(2) s , β⁺ (99.3%) , ¹⁶⁰Lu , rowspan=2, 0+ , rowspan=2, , rowspan=2, , - , α (0.7%) , ¹⁵⁶Yb , -id=Hafnium-161 , rowspan=2, ¹⁶¹Hf , rowspan=2 style="text-align:right" , 72 , rowspan=2 style="text-align:right" , 89 , rowspan=2, 160.950278(25) , rowspan=2, 18.4(4) s , β⁺ (99.71%) , ¹⁶¹Lu , rowspan=2, (7/2−) , rowspan=2, , rowspan=2, , - , α (0.29%) , ¹⁵⁷Yb , -id=Hafnium-161m , style="text-indent:1em" , ^161mHf , colspan="3" style="text-indent:2em" , 329.0(5) keV , 4.8(2) μs , IT , ¹⁶¹Hf , (13/2+) , , , -id=Hafnium-162 , rowspan=2, ¹⁶²Hf , rowspan=2 style="text-align:right" , 72 , rowspan=2 style="text-align:right" , 90 , rowspan=2, 161.9472155(96) , rowspan=2, 39.4(9) s , β⁺ (99.99%) , ¹⁶²Lu , rowspan=2, 0+ , rowspan=2, , rowspan=2, , - , α (0.008%) , ¹⁵⁸Yb , -id=Hafnium-163 , ¹⁶³Hf , style="text-align:right" , 72 , style="text-align:right" , 91 , 162.947107(28) , 40.0(6) s , β⁺ , ¹⁶³Lu , (5/2−) , , , -id=Hafnium-164 , ¹⁶⁴Hf , style="text-align:right" , 72 , style="text-align:right" , 92 , 163.944371(17) , 111(8) s , β⁺ , ¹⁶⁴Lu , 0+ , , , -id=Hafnium-165 , ¹⁶⁵Hf , style="text-align:right" , 72 , style="text-align:right" , 93 , 164.944567(30) , 76(4) s , β⁺ , ¹⁶⁵Lu , (5/2−) , , , -id=Hafnium-166 , ¹⁶⁶Hf , style="text-align:right" , 72 , style="text-align:right" , 94 , 165.942180(30) , 6.77(30) min , β⁺ , ¹⁶⁶Lu , 0+ , , , -id=Hafnium-167 , ¹⁶⁷Hf , style="text-align:right" , 72 , style="text-align:right" , 95 , 166.942600(30) , 2.05(5) min , β⁺ , ¹⁶⁷Lu , (5/2)− , , , -id=Hafnium-168 , rowspan=2, ¹⁶⁸Hf , rowspan=2 style="text-align:right" , 72 , rowspan=2 style="text-align:right" , 96 , rowspan=2, 167.940568(30) , rowspan=2, 25.95(20) min , EC (98%) , ¹⁶⁸Lu , rowspan=2, 0+ , rowspan=2, , rowspan=2, , - , β⁺ (2%) , ¹⁶⁸Lu , -id=Hafnium-169 , ¹⁶⁹Hf , style="text-align:right" , 72 , style="text-align:right" , 97 , 168.941259(30) , 3.24(4) min , β⁺ , ¹⁶⁹Lu , (5/2−) , , , -id=Hafnium-170 , ¹⁷⁰Hf , style="text-align:right" , 72 , style="text-align:right" , 98 , 169.939609(30) , 16.01(13) h , EC , ¹⁷⁰Lu , 0+ , , , -id=Hafnium-171 , ¹⁷¹Hf , style="text-align:right" , 72 , style="text-align:right" , 99 , 170.940492(31) , 12.1(4) h , β⁺ , ¹⁷¹Lu , 7/2+ , , , -id=Hafnium-171m , style="text-indent:1em" , ^171mHf , colspan="3" style="text-indent:2em" , 21.93(9) keV , 29.5(9) s , IT , ¹⁷¹Hf , 1/2− , , , -id=Hafnium-172 , ¹⁷²Hf , style="text-align:right" , 72 , style="text-align:right" , 100 , 171.939450(26) , 1.87(3) y , EC , ¹⁷²Lu , 0+ , , , -id=Hafnium-172m , style="text-indent:1em" , ^172mHf , colspan="3" style="text-indent:2em" , 2005.84(11) keV , 163(3) ns , IT , ¹⁷²Hf , (8−) , , , -id=Hafnium-173 , ¹⁷³Hf , style="text-align:right" , 72 , style="text-align:right" , 101 , 172.940513(30) , 23.6(1) h , β⁺ , ¹⁷³Lu , 1/2− , , , -id=Hafnium-173m1 , style="text-indent:1em" , ^173m1Hf , colspan="3" style="text-indent:2em" , 107.16(5) keV , 180(8) ns , IT , ¹⁷³Hf , 5/2− , , , -id=Hafnium-173m2 , style="text-indent:1em" , ^173m2Hf , colspan="3" style="text-indent:2em" , 197.47(10) keV , 160(40) ns , IT , ¹⁷³Hf , 7/2+ , , , -id=Hafnium-174 , ¹⁷⁴Hf primordial

radionuclide A radionuclide (radioactive nuclide, radioisotope or radioactive isotope) is a nuclide that has excess numbers of either neutrons or protons, giving it excess nuclear energy, and making it unstable. This excess energy can be used in one of three ...

, style="text-align:right" , 72 , style="text-align:right" , 102 , 173.9400484(24) , , αTheorized to also undergo β⁺β⁺ decay to ¹⁷⁴Yb , ¹⁷⁰Yb , 0+ , 0.0016(12) , , -id=Hafnium-174m1 , style="text-indent:1em" , ^174m1Hf , colspan="3" style="text-indent:2em" , 1549.26(4) keV , 138(4) ns , IT , ''¹⁷⁴Hf'' , 6+ , , , -id=Hafnium-174m2 , style="text-indent:1em" , ^174m2Hf , colspan="3" style="text-indent:2em" , 1797.59(7) keV , 2.39(4) μs , IT , ''¹⁷⁴Hf'' , 8− , , , -id=Hafnium-174m3 , style="text-indent:1em" , ^174m3Hf , colspan="3" style="text-indent:2em" , 3312.07(6) keV , 3.7(2) μs , IT , ''¹⁷⁴Hf'' , 14+ , , , -id=Hafnium-175 , ¹⁷⁵Hf , style="text-align:right" , 72 , style="text-align:right" , 103 , 174.9415114(25) , 70.65(19) d , EC , ¹⁷⁵Lu , 5/2− , , , -id=Hafnium-175m1 , style="text-indent:1em" , ^175m1Hf , colspan="3" style="text-indent:2em" , 125.89(12) keV , 53.7(15) μs , IT , ¹⁷⁵Hf , 1/2− , , , -id=Hafnium-175m2 , style="text-indent:1em" , ^175m2Hf , colspan="3" style="text-indent:2em" , 1433.41(12) keV , 1.10(8) μs , IT , ¹⁷⁵Hf , 19/2+ , , , -id=Hafnium-175m3 , style="text-indent:1em" , ^175m3Hf , colspan="3" style="text-indent:2em" , 3015.6(4) keV , 1.21(15) μs , IT , ¹⁷⁵Hf , 35/2− , , , -id=Hafnium-175m4 , style="text-indent:1em" , ^175m4Hf , colspan="3" style="text-indent:2em" , 4636.2(12) keV , 1.9(1) μs , IT , ¹⁷⁵Hf , 45/2+ , , , -id=Hafnium-176 , ¹⁷⁶HfUsed in lutetium-hafnium dating , style="text-align:right" , 72 , style="text-align:right" , 104 , 175.9414098(16) , colspan=3 align=center,

Observationally Stable Stable nuclides are isotopes of a chemical element whose nucleons are in a configuration that does not permit them the surplus energy required to produce a radioactive emission. The nuclei of such isotopes are not radioactive and unlike radionuc ...

Believed to undergo α decay to ¹⁷²Yb , 0+ , 0.0526(70) , , -id=Hafnium-176m1 , style="text-indent:1em" , ^176m1Hf , colspan="3" style="text-indent:2em" , 1333.07(7) keV , 9.6(3) μs , IT , ¹⁷⁶Hf , 6+ , , , -id=Hafnium-176m2 , style="text-indent:1em" , ^176m2Hf , colspan="3" style="text-indent:2em" , 1559.31(9) keV , 9.9(2) μs , IT , ¹⁷⁶Hf , 8− , , , -id=Hafnium-176m3 , style="text-indent:1em" , ^176m3Hf , colspan="3" style="text-indent:2em" , 2865.8(7) keV , 401(6) μs , IT , ¹⁷⁶Hf , 14− , , , -id=Hafnium-176m4 , style="text-indent:1em" , ^176m4Hf , colspan="3" style="text-indent:2em" , 4863.6(9) keV , 43(4) μs , IT , ¹⁷⁶Hf , 22− , , , -id=Hafnium-177 , ¹⁷⁷Hf , style="text-align:right" , 72 , style="text-align:right" , 105 , 176.9432302(15) , colspan=3 align=center, Observationally StableBelieved to undergo α decay to ¹⁷³Yb with a half-life over 1.3×10¹⁸ y. , 7/2− , 0.1860(16) , , -id=Hafnium-177m1 , style="text-indent:1em" , ^177m1Hf , colspan="3" style="text-indent:2em" , 1315.4502(8) keV , 1.09(5) s , IT , ¹⁷⁷Hf , 23/2+ , , , -id=Hafnium-177m2 , style="text-indent:1em" , ^177m2Hf , colspan="3" style="text-indent:2em" , 1342.4(10) keV , 55.9(12) μs , IT , ¹⁷⁷Hf , (19/2−) , , , -id=Hafnium-177m3 , style="text-indent:1em" , ^177m3Hf , colspan="3" style="text-indent:2em" , 2740.02(15) keV , 51.4(5) min , IT , ¹⁷⁷Hf , 37/2− , , , -id=Hafnium-178 , ¹⁷⁸Hf , style="text-align:right" , 72 , style="text-align:right" , 106 , 177.9437083(15) , colspan=3 align=center, Observationally StableBelieved to undergo α decay to ¹⁷⁴Yb , 0+ , 0.2728(28) , , -id=Hafnium-178m1 , style="text-indent:1em" , ^178m1Hf , colspan="3" style="text-indent:2em" , 1147.416(6) keV , 4.0(2) s , IT , ¹⁷⁸Hf , 8− , , , -id=Hafnium-178m2 , style="text-indent:1em" , ^178m2Hf , colspan="3" style="text-indent:2em" , 2446.09(8) keV , 31(1) y , IT , ¹⁷⁸Hf , 16+ , , , -id=Hafnium-178m3 , style="text-indent:1em" , ^178m3Hf , colspan="3" style="text-indent:2em" , 2572.4(3) keV , 68(2) μs , IT , ¹⁷⁸Hf , 14− , , , -id=Hafnium-179 , ¹⁷⁹Hf , style="text-align:right" , 72 , style="text-align:right" , 107 , 178.9458257(15) , colspan=3 align=center, Observationally StableBelieved to undergo α decay to ¹⁷⁵Yb , 9/2+ , 0.1362(11) , , -id=Hafnium-179m1 , style="text-indent:1em" , ^179m1Hf , colspan="3" style="text-indent:2em" , 375.0352(25) keV , 18.67(4) s , IT , ¹⁷⁹Hf , 1/2− , , , -id=Hafnium-179m2 , style="text-indent:1em" , ^179m2Hf , colspan="3" style="text-indent:2em" , 1106.412(33) keV , 25.00(17) d , IT , ¹⁷⁹Hf , 25/2− , , , -id=Hafnium-179m3 , style="text-indent:1em" , ^179m3Hf , colspan="3" style="text-indent:2em" , 3775.2(21) keV , 15(5) μs , IT , ¹⁷⁹Hf , (43/2+) , , , -id=Hafnium-180 , ¹⁸⁰Hf , style="text-align:right" , 72 , style="text-align:right" , 108 , 179.9465595(15) , colspan=3 align=center, Observationally StableBelieved to undergo α decay to ¹⁷⁶Yb , 0+ , 0.3508(33) , , -id=Hafnium-180m1 , rowspan=2 style="text-indent:1em" , ^180m1Hf , rowspan=2 colspan="3" style="text-indent:2em" , 1141.552(15) keV , rowspan=2, 5.53(2) h , IT (99.69%) , ¹⁸⁰Hf , rowspan=2, 8− , rowspan=2, , rowspan=2, , - , β⁻ (0.31%) , ^180m1Ta , -id=Hafnium-180m2 , style="text-indent:1em" , ^180m2Hf , colspan="3" style="text-indent:2em" , 1374.36(4) keV , 570(20) μs , IT , ¹⁸⁰Hf , 4− , , , -id=Hafnium-180m3 , style="text-indent:1em" , ^180m3Hf , colspan="3" style="text-indent:2em" , 2485.5(5) keV , 0.94(11) μs , IT , ¹⁸⁰Hf , 12+ , , , -id=Hafnium-180m4 , style="text-indent:1em" , ^180m4Hf , colspan="3" style="text-indent:2em" , 3599.0(10) keV , 90(10) μs , IT , ¹⁸⁰Hf , (18−) , , , -id=Hafnium-181 , ¹⁸¹Hf , style="text-align:right" , 72 , style="text-align:right" , 109 , 180.9491108(15) , 42.39(6) d , β⁻ , ¹⁸¹Ta , 1/2− , , , -id=Hafnium-181m1 , style="text-indent:1em" , ^181m1Hf , colspan="3" style="text-indent:2em" , 595.27(4) keV , 80(5) μs , IT , ¹⁸¹Hf , (9/2+) , , , -id=Hafnium-181m2 , style="text-indent:1em" , ^181m2Hf , colspan="3" style="text-indent:2em" , 1043.5(8) keV , ~100 μs , IT , ¹⁸¹Hf , (17/2+) , , , -id=Hafnium-181m3 , style="text-indent:1em" , ^181m3Hf , colspan="3" style="text-indent:2em" , 1741.9(13) keV , 1.5(5) ms , IT , ¹⁸¹Hf , (25/2−) , , , -id=Hafnium-182 , ¹⁸²Hf , style="text-align:right" , 72 , style="text-align:right" , 110 , 181.9505637(66) , 8.90(9)×10⁶ y , β⁻ , ¹⁸²Ta , 0+ , , , -id=Hafnium-182m1 , rowspan=2 style="text-indent:1em" , ^182m1Hf , rowspan=2 colspan="3" style="text-indent:2em" , 1172.87(18) keV , rowspan=2, 61.5(15) min , β⁻ (54%) , ¹⁸²Ta , rowspan=2, 8− , rowspan=2, , rowspan=2, , - , IT (46%) , ¹⁸²Hf , -id=Hafnium-182m2 , style="text-indent:1em" , ^182m2Hf , colspan="3" style="text-indent:2em" , 2571.3(12) keV , 40(10) μs , IT , ¹⁸²Hf , (13+) , , , -id=Hafnium-183 , ¹⁸³Hf , style="text-align:right" , 72 , style="text-align:right" , 111 , 182.953533(32) , 1.018(2) h , β⁻ , ¹⁸³Ta , (3/2−) , , , -id=Hafnium-183m , style="text-indent:1em" , ^183mHf , colspan="3" style="text-indent:2em" , 1464(64) keV , 40(30) s , IT , ¹⁸³Hf , 27/2−# , , , -id=Hafnium-184 , ¹⁸⁴Hf , style="text-align:right" , 72 , style="text-align:right" , 112 , 183.955449(43) , 4.12(5) h , β⁻ , ¹⁸⁴Ta , 0+ , , , -id=Hafnium-184m1 , style="text-indent:1em" , ^184m1Hf , colspan="3" style="text-indent:2em" , 1272.2(4) keV , 48(10) s , IT , ¹⁸⁴Hf , 8− , , , -id=Hafnium-184m2 , style="text-indent:1em" , ^184m2Hf , colspan="3" style="text-indent:2em" , 2477(10) keV , 16(7) min , , , 15+# , , , -id=Hafnium-185 , ¹⁸⁵Hf , style="text-align:right" , 72 , style="text-align:right" , 113 , 184.958862(69) , 3.5(6) min , β⁻ , ¹⁸⁵Ta , (9/2−) , , , -id=Hafnium-186 , ¹⁸⁶Hf , style="text-align:right" , 72 , style="text-align:right" , 114 , 185.960897(55) , 2.6(12) min , β⁻ , ¹⁸⁶Ta , 0+ , , , -id=Hafnium-186m , style="text-indent:1em" , ^186mHf , colspan="3" style="text-indent:2em" , 2968(43) keV , >20 s , , , 17+# , , , -id=Hafnium-187 , ¹⁸⁷Hf , style="text-align:right" , 72 , style="text-align:right" , 115 , 186.96457(22)# , 14# s
300 ns, , , 9/2−# , , , -id=Hafnium-187m , style="text-indent:1em" , ^187mHf , colspan="3" style="text-indent:2em" , 500(300)# keV , 270(80) ns , IT , ¹⁸⁷Hf , 3/2−# , , , -id=Hafnium-188 , ¹⁸⁸Hf , style="text-align:right" , 72 , style="text-align:right" , 116 , 187.96690(32)# , 7# s
300 ns, , , 0+ , , , -id=Hafnium-189 , ¹⁸⁹Hf , style="text-align:right" , 72 , style="text-align:right" , 117 , 188.97085(32)# , 400# ms
300 ns, , , 3/2−# , , , -id=Hafnium-190 , ¹⁹⁰Hf , style="text-align:right" , 72 , style="text-align:right" , 118 , 189.97338(43)# , 600# ms
300 ns, , , 0+ , , , -id=Hafnium-191 , ¹⁹¹Hf , style="text-align:right" , 72 , style="text-align:right" , 119 , , , , , , , , -id=Hafnium-192 , ¹⁹²Hf , style="text-align:right" , 72 , style="text-align:right" , 120 , , , , , 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; it has 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 Dm ...

List of isotopes

See also

References