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Isotopes of thulium



Naturally occurring thulium (Tm) is composed of 1 stable isotope, Tm-169 (100% natural abundance). 31 radioisotopes have been characterized, with the most stable being Tm-171 with a half-life of 1.92 years, Tm-170 with a half-life of 128.6 days, Tm-168 with a half-life of 93.1 days, and Tm-167 with a half-life of 9.25 days. All of the remaining radioactive isotopes have half-lifes that are less than 64 hours, and the majority of these have half lifes that are less than 2 minutes. This element also has 14 meta states, with the most stable being Tm-164m (t½ 5.1 minutes), Tm-160m (t½ 74.5 seconds) and Tm-155m (t½ 45 seconds).

Additional recommended knowledge

The isotopes of thulium range in atomic weight from 145.966 u (Tm-146) to 176.949 u (Tm-177). The primary decay mode before the most abundant stable isotope, Tm-169, is electron capture, and the primary mode after is beta emission. The primary decay products before Tm-169 are element 68 (erbium) isotopes, and the primary products after are element 70 (ytterbium) isotopes.
Standard atomic mass: 168.93421(2) u

Table

nuclide
symbol
Z(p) N(n)  
isotopic mass (u)
 
half-life nuclear
spin
representative
isotopic
composition
(mole fraction)
range of natural
variation
(mole fraction)
excitation energy
145Tm 69 76 144.97007(43)# 3.1(3) µs (11/2-)
146Tm 69 77 145.96643(43)# 240(30) ms (6-)
146mTm 71(6) keV 72(23) ms (10+)
147Tm 69 78 146.96096(32)# 0.58(3) s 11/2-
147mTm 60(5) keV 360(40) µs 3/2+
148Tm 69 79 147.95784(43)# 0.7(2) s (10+)
148mTm 0.7 s
149Tm 69 80 148.95272(32)# 0.9(2) s (11/2-)
150Tm 69 81 149.94996(21)# 3# s (1+)
150m1Tm 140(140)# keV 2.20(6) s (6-)
150m2Tm 810(140)# keV 5.2(3) ms (10+)
151Tm 69 82 150.945483(22) 4.17(10) s (11/2-)
151m1Tm 92(7) keV 6.6(14) s (1/2+)
151m2Tm 2655.67(22) keV 451(24) ns (27/2-)
152Tm 69 83 151.94442(8) 8.0(10) s (2#)-
152m1Tm 100(80)# keV 5.2(6) s (9)+
152m2Tm 2555.05(19)+X keV 294(12) ns (17+)
153Tm 69 84 152.942012(20) 1.48(1) s (11/2-)
153mTm 43.2(2) keV 2.5(2) s (1/2+)
154Tm 69 85 153.941568(15) 8.1(3) s (2-)
154mTm 70(50) keV 3.30(7) s (9+)
155Tm 69 86 154.939199(14) 21.6(2) s (11/2-)
155mTm 41(6) keV 45(3) s (1/2+)
156Tm 69 87 155.938980(17) 83.8(18) s 2-
156mTm 203.6(5) keV ~400 ns (11-)
157Tm 69 88 156.93697(3) 3.63(9) min 1/2+
158Tm 69 89 157.936980(27) 3.98(6) min 2-
158mTm 50(100)# keV ~20 ns (5+)
159Tm 69 90 158.93498(3) 9.13(16) min 5/2+
160Tm 69 91 159.93526(4) 9.4(3) min 1-
160m1Tm 70(20) keV 74.5(15) s 5(+#)
160m2Tm 98.2+X keV ~200 ns (8)
161Tm 69 92 160.93355(3) 30.2(8) min 7/2+
161m1Tm 7.4(2) keV 5# min 1/2+
161m2Tm 78.20(3) keV 110(3) ns 7/2-
162Tm 69 93 161.933995(28) 21.70(19) min 1-
162mTm 130(40) keV 24.3(17) s 5+
163Tm 69 94 162.932651(6) 1.810(5) h 1/2+
164Tm 69 95 163.93356(3) 2.0(1) min 1+
164mTm 10(6) keV 5.1(1) min 6-
165Tm 69 96 164.932435(4) 30.06(3) h 1/2+
166Tm 69 97 165.933554(13) 7.70(3) h 2+
166mTm 122(8) keV 340(25) ms 6-
167Tm 69 98 166.9328516(29) 9.25(2) d 1/2+
167m1Tm 179.480(19) keV 1.16(6) µs (7/2)+
167m2Tm 292.820(20) keV 0.9(1) µs 7/2-
168Tm 69 99 167.934173(3) 93.1(2) d 3+
169Tm 69 100 168.9342133(27) STABLE 1/2+ 1.0000
170Tm 69 101 169.9358014(27) 128.6(3) d 1-
170mTm 183.197(4) keV 4.12(13) µs (3)+
171Tm 69 102 170.9364294(28) 1.92(1) a 1/2+
171mTm 424.9560(15) keV 2.60(2) µs 7/2-
172Tm 69 103 171.938400(6) 63.6(2) h 2-
173Tm 69 104 172.939604(5) 8.24(8) h (1/2+)
173mTm 317.73(20) keV 10(3) µs (7/2-)
174Tm 69 105 173.94217(5) 5.4(1) min (4)-
175Tm 69 106 174.94384(5) 15.2(5) min (1/2+)
176Tm 69 107 175.94699(11) 1.85(3) min (4+)
177Tm 69 108 176.94904(32)# 90(6) s (7/2-)
178Tm 69 109 177.95264(43)# 30# s
179Tm 69 110 178.95534(54)# 20# s 1/2+#

Notes

  • Values marked # are not purely derived from experimental data, but at least partly from systematic trends. Spins with weak assignment arguments are enclosed in parentheses.
  • Uncertainties are given in concise form in parentheses after the corresponding last digits. Uncertainty values denote one standard deviation, except isotopic composition and standard atomic mass from IUPAC which use expanded uncertainties.

References

  • Isotope masses from Ame2003 Atomic Mass Evaluation by G. Audi, A.H. Wapstra, C. Thibault, J. Blachot and O. Bersillon in Nuclear Physics A729 (2003).
  • Isotopic compositions and standard atomic masses from Atomic weights of the elements. Review 2000 (IUPAC Technical Report). Pure Appl. Chem. Vol. 75, No. 6, pp. 683-800, (2003) and Atomic Weights Revised (2005).
  • Half-life, spin, and isomer data selected from these sources. Editing notes on this article's talk page.
    • Audi, Bersillon, Blachot, Wapstra. The Nubase2003 evaluation of nuclear and decay properties, Nuc. Phys. A 729, pp. 3-128 (2003).
    • National Nuclear Data Center, Brookhaven National Laboratory. Information extracted from the NuDat 2.1 database (retrieved Sept. 2005).
    • David R. Lide (ed.), Norman E. Holden in CRC Handbook of Chemistry and Physics, 85th Edition, online version. CRC Press. Boca Raton, Florida (2005). Section 11, Table of the Isotopes.


Isotopes of erbium Isotopes of thulium Isotopes of ytterbium
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This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Isotopes_of_thulium". A list of authors is available in Wikipedia.
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