Naturally occurring

terbium Terbium is a chemical element; it has Symbol (chemistry), symbol Tb and atomic number 65. It is a silvery-white, rare earth element, rare earth metal that is malleable and ductile. The ninth member of the lanthanide series, terbium is a fairly ele ...

(₆₅Tb) is composed of one 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 ...

, ¹⁵⁹Tb. Thirty-seven radioisotopes have been characterized, with the most stable being ¹⁵⁸Tb 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 180 years, ¹⁵⁷Tb with a half-life of 71 years, and ¹⁶⁰Tb with a half-life of 72.3 days. All of the remaining radioactive isotopes have half-lives that are less than 6.907 days, and the majority of these have half-lives that are less than 24 seconds. This element also has 27 meta states, with the most stable being ^156m1Tb (t_1/2 = 24.4 hours), ^154m2Tb (t_1/2 = 22.7 hours) and ^154m1Tb (t_1/2 = 9.4 hours). The primary decay mode before the most abundant stable isotope, ¹⁵⁹Tb, is

electron capture Electron capture (K-electron capture, also K-capture, or L-electron capture, L-capture) is a process in which the proton-rich nucleus of an electrically neutral atom absorbs an inner atomic electron, usually from the K or L electron shells. Th ...

, and the primary mode behind is

beta decay In nuclear physics, beta decay (β-decay) is a type of radioactive decay in which an atomic nucleus emits a beta particle (fast energetic electron or positron), transforming into an isobar of that nuclide. For example, beta decay of a neutron ...

. The primary decay products before ¹⁵⁹Tb are element Gd ( gadolinium) isotopes, and the primary products after ¹⁵⁹Tb are element Dy (

dysprosium Dysprosium is a chemical element; it has symbol Dy and atomic number 66. It is a rare-earth element in the lanthanide series with a metallic silver luster. Dysprosium is never found in nature as a free element, though, like other lanthanides, it ...

) isotopes.

List of isotopes

, -id=Terbium-135 , ¹³⁵Tb , style="text-align:right" , 65 , style="text-align:right" , 70 , 134.96452(43)# , 1.01(28) ms , p , ¹³⁴Gd , (7/2−) , , -id=Terbium-139 , ¹³⁹Tb , style="text-align:right" , 65 , style="text-align:right" , 74 , 138.94833(32)# , 1.6(2) s , β⁺ , ¹³⁹Gd , 5/2−# , , -id=Terbium-140 , rowspan=3, ¹⁴⁰Tb , rowspan=3 style="text-align:right" , 65 , rowspan=3 style="text-align:right" , 75 , rowspan=3, 139.94581(86) , rowspan=3, 2.29(15) s , β⁺ (99.74%) , ¹⁴⁰Gd , rowspan=3, (7+) , rowspan=3, , - , EC (<3%) , ¹⁴⁰Gd , - , β⁺, p (0.26%) , ¹³⁹Eu , -id=Terbium-141 , ¹⁴¹Tb , style="text-align:right" , 65 , style="text-align:right" , 76 , 140.94145(11) , 3.5(2) s , β⁺ , ¹⁴¹Gd , (5/2−) , , -id=Terbium-141m , style="text-indent:1em" , ^141mTbOrder of ground state and isomer is uncertain.Discovery of this isotope is disputed. , colspan="3" style="text-indent:2em" , 0(200)# keV , 7.9(6) s , β⁺ , ¹⁴¹Gd , 11/2−# , , -id=Terbium-142 , rowspan=3, ¹⁴²Tb , rowspan=3 style="text-align:right" , 65 , rowspan=3 style="text-align:right" , 77 , rowspan=3, 141.93928(75) , rowspan=3, 597(17) ms , β⁺ (96.8%) , ¹⁴²Gd , rowspan=3, 1+ , rowspan=3, , - , EC (3.2%) , ¹⁴²Gd , - , β⁺, p (0.0022%) , ¹⁴¹Eu , -id=Terbium-142m1 , style="text-indent:1em" , ^142m1Tb , colspan="3" style="text-indent:2em" , 279.7(4) keV , 303(17) ms , IT , ¹⁴²Tb , 5− , , -id=Terbium-142m2 , style="text-indent:1em" , ^142m2Tb , colspan="3" style="text-indent:2em" , 652.1(6) keV , 26(1) μs , IT , ¹⁴²Tb , 8+ , , -id=Terbium-143 , ¹⁴³Tb , style="text-align:right" , 65 , style="text-align:right" , 78 , 142.935137(55) , 12(1) s , β⁺ , ¹⁴³Gd , (11/2−) , , -id=Terbium-143m , style="text-indent:1em" , ^143mTb , colspan="3" style="text-indent:2em" , 0(100)# keV , 17(4) s , , , 5/2+# , , -id=Terbium-144 , ¹⁴⁴Tb , style="text-align:right" , 65 , style="text-align:right" , 79 , 143.933045(30) , ~1 s , β⁺ , ¹⁴⁴Gd , 1+ , , -id=Terbium-144m1 , rowspan=2 style="text-indent:1em" , ^144m1Tb , rowspan=2 colspan="3" style="text-indent:2em" , 396.9(5) keV , rowspan=2, 4.25(15) s , IT (66%) , ¹⁴⁴Tb , rowspan=2, 6− , rowspan=2, , - , β⁺ (34%) , ¹⁴⁴Gd , -id=Terbium-144m2 , style="text-indent:1em" , ^144m2Tb , colspan="3" style="text-indent:2em" , 476.2(5) keV , 2.8(3) μs , IT , ¹⁴⁴Tb , (8−) , , -id=Terbium-144m3 , style="text-indent:1em" , ^144m3Tb , colspan="3" style="text-indent:2em" , 517.1(5) keV , 670(60) ns , IT , ¹⁴⁴Tb , (9+) , , -id=Terbium-144m4 , style="text-indent:1em" , ^144m4Tb , colspan="3" style="text-indent:2em" , 544.5(6) keV , <300 ns , IT , ¹⁴⁴Tb , (10+) , , -id=Terbium-145 , ¹⁴⁵Tb , style="text-align:right" , 65 , style="text-align:right" , 80 , 144.92872(12) , 30.9(6) s , β⁺ , ¹⁴⁵Gd , (11/2−) , , -id=Terbium-145m , style="text-indent:1em" , ^145mTb , colspan="3" style="text-indent:2em" , 860(230) keV , , , , (3/2+) , , -id=Terbium-146 , ¹⁴⁶Tb , style="text-align:right" , 65 , style="text-align:right" , 81 , 145.927253(48) , 8(4) s , β⁺ , ¹⁴⁶Gd , 1+ , , -id=Terbium-146m1 , style="text-indent:1em" , ^146m1Tb , colspan="3" style="text-indent:2em" , 150(100)# keV , 24.1(5) s , β⁺ , ¹⁴⁶Gd , 5− , , -id=Terbium-146m2 , style="text-indent:1em" , ^146m2Tb , colspan="3" style="text-indent:2em" , 930(100)# keV , 1.18(2) ms , IT , ¹⁴⁶Tb , 10+ , , -id=Terbium-147 , ¹⁴⁷Tb , style="text-align:right" , 65 , style="text-align:right" , 82 , 146.9240546(87) , 1.64(3) h , β⁺ , ¹⁴⁷Gd , (1/2+) , , -id=Terbium-147m , style="text-indent:1em" , ^147mTb , colspan="3" style="text-indent:2em" , 50.6(9) keV , 1.87(5) min , β⁺ , ¹⁴⁷Gd , (11/2−) , , -id=Terbium-148 , ¹⁴⁸Tb , style="text-align:right" , 65 , style="text-align:right" , 83 , 147.924275(13) , 60(1) min , β⁺ , ¹⁴⁸Gd , 2− , , -id=Terbium-148m1 , style="text-indent:1em" , ^148m1Tb , colspan="3" style="text-indent:2em" , 90.1(3) keV , 2.20(5) min , β⁺ , ¹⁴⁸Gd , (9)+ , , -id=Terbium-148m2 , style="text-indent:1em" , ^148m2Tb , colspan="3" style="text-indent:2em" , 8618.6(10) keV , 1.310(7) μs , IT , ¹⁴⁸Tb , (27+) , , -id=Terbium-149 , rowspan=2, ¹⁴⁹Tb , rowspan=2 style="text-align:right" , 65 , rowspan=2 style="text-align:right" , 84 , rowspan=2, 148.9232538(39) , rowspan=2, 4.118(25) h , β⁺ (83.3%) , ¹⁴⁹Gd , rowspan=2, 1/2+ , rowspan=2, , - , α (16.7%) , ¹⁴⁵Eu , -id=Terbium-149m , rowspan=2 style="text-indent:1em" , ^149mTb , rowspan=2 colspan="3" style="text-indent:2em" , 35.78(13) keV , rowspan=2, 4.16(4) min , β⁺ (99.98%) , ¹⁴⁹Gd , rowspan=2, 11/2− , rowspan=2, , - , α (0.022%) , ¹⁴⁵Eu , -id=Terbium-150 , ¹⁵⁰Tb , style="text-align:right" , 65 , style="text-align:right" , 85 , 149.9236648(79) , 3.48(16) h , β⁺ , ¹⁵⁰Gd , (2)− , , -id=Terbium-150m , style="text-indent:1em" , ^150mTb , colspan="3" style="text-indent:2em" , 461(27) keV , 5.8(2) min , β⁺ , ¹⁵⁰Gd , 9+ , , -id=Terbium-151 , rowspan=2, ¹⁵¹Tb , rowspan=2 style="text-align:right" , 65 , rowspan=2 style="text-align:right" , 86 , rowspan=2, 150.9231090(44) , rowspan=2, 17.609(1) h , β⁺ (99.99%) , ¹⁵¹Gd , rowspan=2, 1/2+ , rowspan=2, , - , α (.0095%) , ¹⁴⁷Eu , -id=Terbium-151m , rowspan=2 style="text-indent:1em" , ^151mTb , rowspan=2 colspan="3" style="text-indent:2em" , 99.53(5) keV , rowspan=2, 25(3) s , IT (93.4%) , ¹⁵¹Tb , rowspan=2, 11/2− , rowspan=2, , - , β⁺ (6.6%) , ¹⁵¹Gd , -id=Terbium-152 , rowspan=3, ¹⁵²Tb , rowspan=3 style="text-align:right" , 65 , rowspan=3 style="text-align:right" , 87 , rowspan=3, 151.924082(43) , rowspan=3, 17.8784(95) h , EC (83%) , rowspan=2, ''¹⁵²Gd'' , rowspan=3, 2− , rowspan=3, , - , β⁺ (17%) , - , α (<7×10⁻⁷%) , ¹⁴⁸Eu , -id=Terbium-152m1 , style="text-indent:1em" , ^152m1Tb , colspan="3" style="text-indent:2em" , 342.15(16) keV , 960(10) ns , IT , ¹⁵²Tb , 5− , , -id=Terbium-152m2 , rowspan=2 style="text-indent:1em" , ^152m2Tb , rowspan=2 colspan="3" style="text-indent:2em" , 501.74(19) keV , rowspan=2, 4.2(1) min , IT (78.9%) , ¹⁵²Tb , rowspan=2, 8+ , rowspan=2, , - , β⁺ (21.1%) , ''¹⁵²Gd'' , -id=Terbium-153 , ¹⁵³Tb , style="text-align:right" , 65 , style="text-align:right" , 88 , 152.9234417(42) , 2.34(1) d , β⁺ , ¹⁵³Gd , 5/2+ , , -id=Terbium-153m , style="text-indent:1em" , ^153mTb , colspan="3" style="text-indent:2em" , 163.175(5) keV , 186(4) μs , IT , ¹⁵³Tb , 11/2− , , -id=Terbium-154 , ¹⁵⁴Tb , style="text-align:right" , 65 , style="text-align:right" , 89 , 153.924684(49) , 9.994(39) h , β⁺ , ¹⁵⁴Gd , 3− , , -id=Terbium-154m1 , style="text-indent:1em" , ^154m1Tb , colspan="3" style="text-indent:2em" , 130(50)# keV , 21.5(4) h , β⁺ , ¹⁵⁴Gd , 0− , , -id=Terbium-154m2 , style="text-indent:1em" , ^154m2Tb , colspan="3" style="text-indent:2em" , 200(150)# keV , 22.7(5) h , β⁺ , ¹⁵⁴Gd , 7− , , -id=Terbium-154m3 , style="text-indent:1em" , ^154m3Tb , colspan="3" style="text-indent:2em" , 405(150)# keV , 513(42) ns , IT , ¹⁵⁴Tb , , , -id=Terbium-155 , ¹⁵⁵Tb , style="text-align:right" , 65 , style="text-align:right" , 90 , 154.923510(11) , 5.32(6) d , EC , ¹⁵⁵Gd , 3/2+ , , -id=Terbium-156 , ¹⁵⁶Tb , style="text-align:right" , 65 , style="text-align:right" , 91 , 155.9247542(40) , 5.35(10) d , β⁺ , ¹⁵⁶Gd , 3− , , -id=Terbium-156m1 , style="text-indent:1em" , ^156m1Tb , colspan="3" style="text-indent:2em" , 88.4(2) keV , 5.3(2) h , IT , ¹⁵⁶Tb , (0+) , , -id=Terbium-156m2 , style="text-indent:1em" , ^156m2Tb , colspan="3" style="text-indent:2em" , 100(50)# keV , 24.4(10) h , IT , ¹⁵⁶Tb , (7−) , , -id=Terbium-157 , ¹⁵⁷Tb , style="text-align:right" , 65 , style="text-align:right" , 92 , 156.9240319(11) , 71(7) y , EC , ¹⁵⁷Gd , 3/2+ , , -id=Terbium-158 , rowspan=2, ¹⁵⁸Tb , rowspan=2 style="text-align:right" , 65 , rowspan=2 style="text-align:right" , 93 , rowspan=2, 157.9254199(14) , rowspan=2, 180(11) y , β⁺ (83.4%) , ¹⁵⁸Gd , rowspan=2, 3− , rowspan=2, , - , β⁻ (16.6%) , ¹⁵⁸Dy , -id=Terbium-158m1 , style="text-indent:1em" , ^158m1Tb , colspan="3" style="text-indent:2em" , 110.3(12) keV , 10.70(17) s , IT , ¹⁵⁸Tb , 0− , , -id=Terbium-158m2 , style="text-indent:1em" , ^158m2Tb , colspan="3" style="text-indent:2em" , 388.39(11) keV , 0.40(4) ms , IT , ¹⁵⁸Tb , 7− , , -id=Terbium-159 , ¹⁵⁹Tb Fission product , style="text-align:right" , 65 , style="text-align:right" , 94 , 158.9253537(12) , colspan=3 align=center, Stable , 3/2+ , 1.0000 , -id=Terbium-160 , ¹⁶⁰Tb , style="text-align:right" , 65 , style="text-align:right" , 95 , 159.9271746(12) , 72.3(2) d , β⁻ , ¹⁶⁰Dy , 3− , , -id=Terbium-161 , ¹⁶¹Tb , style="text-align:right" , 65 , style="text-align:right" , 96 , 160.9275768(13) , 6.948(5) d , β⁻ , ¹⁶¹Dy , 3/2+ , , -id=Terbium-162 , ¹⁶²Tb , style="text-align:right" , 65 , style="text-align:right" , 97 , 161.9292754(22) , 7.60(15) min , β⁻ , ¹⁶²Dy , (1−) , , -id=Terbium-162m , style="text-indent:1em" , ^162mTb , colspan="3" style="text-indent:2em" , 286(3) keV , 10# min , , , 4−# , , -id=Terbium-163 , ¹⁶³Tb , style="text-align:right" , 65 , style="text-align:right" , 98 , 162.9306536(44) , 19.5(3) min , β⁻ , ¹⁶³Dy , 3/2+ , , -id=Terbium-164 , ¹⁶⁴Tb , style="text-align:right" , 65 , style="text-align:right" , 99 , 163.9333276(20) , 3.0(1) min , β⁻ , ¹⁶⁴Dy , (5+) , , -id=Terbium-164m , style="text-indent:1em" , ^164mTb , colspan="3" style="text-indent:2em" , 145(12) keV , 2# min , , , 2+# , , -id=Terbium-165 , ¹⁶⁵Tb , style="text-align:right" , 65 , style="text-align:right" , 100 , 164.9349552(17) , 2.11(10) min , β⁻ , ¹⁶⁵Dy , (3/2+) , , -id=Terbium-165m , style="text-indent:1em" , ^165mTb , colspan="3" style="text-indent:2em" , 207(5) keV , 0.81(8) μs , IT , ¹⁶⁵Tb , (7/2−) , , -id=Terbium-166 , ¹⁶⁶Tb , style="text-align:right" , 65 , style="text-align:right" , 101 , 165.9379397(16) , 27.1(15) s , β⁻ , ¹⁶⁶Dy , (1−) , , -id=Terbium-166m , style="text-indent:1em" , ^166mTb , colspan="3" style="text-indent:2em" , 159.0(15) keV , 3.5(4) μs , IT , ¹⁶⁶Tb , 4−# , , -id=Terbium-167 , ¹⁶⁷Tb , style="text-align:right" , 65 , style="text-align:right" , 102 , 166.9400070(21) , 18.9(16) s , β⁻ , ¹⁶⁷Dy , (3/2+) , , -id=Terbium-167m , style="text-indent:1em" , ^167mTb , colspan="3" style="text-indent:2em" , 200(6) keV , 1.2(1) μs , IT , ¹⁶⁷Tb , (7/2−) , , -id=Terbium-168 , ¹⁶⁸Tb , style="text-align:right" , 65 , style="text-align:right" , 103 , 167.9433371(45) , 9.4(4) s , β⁻ , ¹⁶⁸Dy , (4−) , , -id=Terbium-168m , style="text-indent:1em" , ^168mTb , colspan="3" style="text-indent:2em" , 211(1) keV , 0.71(3) μs , IT , ¹⁶⁸Tb , (6+) , , -id=Terbium-169 , ¹⁶⁹Tb , style="text-align:right" , 65 , style="text-align:right" , 104 , 168.94581(32)# , 5.13(32) s , β⁻ , ¹⁶⁹Dy , 3/2+# , , -id=Terbium-170 , ¹⁷⁰Tb , style="text-align:right" , 65 , style="text-align:right" , 105 , 169.94986(32)# , 960(78) ms , β⁻ , ¹⁷⁰Dy , 2−# , , -id=Terbium-171 , ¹⁷¹Tb , style="text-align:right" , 65 , style="text-align:right" , 106 , 170.95301(43)# , 1.23(10) s , β⁻ , ¹⁷¹Dy , 3/2+# , , -id=Terbium-172 , ¹⁷²Tb , style="text-align:right" , 65 , style="text-align:right" , 107 , 171.95739(54)# , 760(190) ms , β⁻ , ¹⁷²Dy , 6+# , , -id=Terbium-173 , ¹⁷³Tb , style="text-align:right" , 65 , style="text-align:right" , 108 , 172.96081(54)# , 400# ms
550 ns, , , 3/2+# , , -id=Terbium-174 , ¹⁷⁴Tb , style="text-align:right" , 65 , style="text-align:right" , 109 , 173.96568(54)# , 240# ms
550 ns, , , 2−# ,

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 Terbium

Terbium Terbium is a chemical element; it has Symbol (chemistry), symbol Tb and atomic number 65. It is a silvery-white, rare earth element, rare earth metal that is malleable and ductile. The ninth member of the lanthanide series, terbium is a fairly ele ...

List of isotopes

See also

References