My watch list
my.chemeurope.com  
Login  

Isotopes of terbium



Naturally occurring terbium (Tb) is composed of 1 stable isotope, 159-Tb. 33 radioisotopes have been characterized, with the most stable being 158-Tb with a half-life of 180 years, 157-Tb with a half-life of 71 years, and 160-Tb with a half-life of 72.3 days. All of the remaining radioactive isotopes have half-lifes that are less than 6.907 days, and the majority of these have half lifes that are less than 24 seconds. This element also has 18 meta states, with the most stable being 156m1-Tb (t½ 24.4 hours), 154m2-Tb (t½ 22.7 hours) and 154m1-Tb (t½ 9.4 hours).

The primary decay mode before the most abundant stable isotope, 159-Tb, is electron capture, and the primary mode behind is beta minus decay. The primary decay products before 159-Tb are element Gd (gadolinium) isotopes, and the primary products behind are element Dy (dysprosium) isotopes.


Standard atomic mass: 158.92535(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
135Tb 65 70 0.94(+33-22) ms (7/2-)
136Tb 65 71 135.96138(64)# 0.2# s
137Tb 65 72 136.95598(64)# 600# ms 11/2-#
138Tb 65 73 137.95316(43)# 800# ms [>200 ns]
139Tb 65 74 138.94829(32)# 1.6(2) s 11/2-#
140Tb 65 75 139.94581(86) 2.4(2) s 5
141Tb 65 76 140.94145(11) 3.5(2) s (5/2-)
141mTb 0(200)# keV 7.9(6) s 11/2-#
142Tb 65 77 141.93874(32)# 597(17) ms 1+
142m1Tb 280.2(10) keV 303(17) ms (5-)
142m2Tb 621.4(11) keV 15(4) µs
143Tb 65 78 142.93512(6) 12(1) s (11/2-)
143mTb 0(100)# keV <21 s 5/2+#
144Tb 65 79 143.93305(3) ~1 s 1+
144m1Tb 396.9(5) keV 4.25(15) s (6-)
144m2Tb 476.2(5) keV 2.8(3) µs (8-)
144m3Tb 517.1(5) keV 670(60) ns (9+)
144m4Tb 544.5(6) keV <300 ns (10+)
145Tb 65 80 144.92927(6) 20# min (3/2+)
145mTb 0(100)# keV 30.9(7) s (11/2-)
146Tb 65 81 145.92725(5) 8(4) s 1+
146m1Tb 150(100)# keV 24.1(5) s 5-
146m2Tb 930(100)# keV 1.18(2) ms (10+)
147Tb 65 82 146.924045(13) 1.64(3) h 1/2+#
147mTb 50.6(9) keV 1.87(5) min (11/2)-
148Tb 65 83 147.924272(15) 60(1) min 2-
148m1Tb 90.1(3) keV 2.20(5) min (9)+
148m2Tb 8618.6(10) keV 1.310(7) µs (27+)
149Tb 65 84 148.923246(5) 4.118(25) h 1/2+
149mTb 35.78(13) keV 4.16(4) min 11/2-
150Tb 65 85 149.923660(8) 3.48(16) h (2-)
150mTb 457(29) keV 5.8(2) min 9+
151Tb 65 86 150.923103(5) 17.609(1) h 1/2(+)
151mTb 99.54(6) keV 25(3) s (11/2-)
152Tb 65 87 151.92407(4) 17.5(1) h 2-
152m1Tb 342.15(16) keV 0.96 µs 5-
152m2Tb 501.74(19) keV 4.2(1) min 8+
153Tb 65 88 152.923435(5) 2.34(1) d 5/2+
153mTb 163.175(5) keV 186(4) µs 11/2-
154Tb 65 89 153.92468(5) 21.5(4) h 0(+#)
154m1Tb 12(7) keV 9.4(4) h 3-
154m2Tb 200(150)# keV 22.7(5) h 7-
154m3Tb 0+Z keV 513(42) ns
155Tb 65 90 154.923505(13) 5.32(6) d 3/2+
156Tb 65 91 155.924747(5) 5.35(10) d 3-
156m1Tb 54(3) keV 24.4(10) h (7-)
156m2Tb 88.4(2) keV 5.3(2) h (0+)
157Tb 65 92 156.9240246(27) 71(7) a 3/2+
158Tb 65 93 157.9254131(28) 180(11) a 3-
158m1Tb 110.3(12) keV 10.70(17) s 0-
158m2Tb 388.37(15) keV 0.40(4) ms 7-
159Tb 65 94 158.9253468(27) STABLE 3/2+ 1.0000
160Tb 65 95 159.9271676(27) 72.3(2) d 3-
161Tb 65 96 160.9275699(28) 6.906(19) d 3/2+
162Tb 65 97 161.92949(4) 7.60(15) min 1-
163Tb 65 98 162.930648(5) 19.5(3) min 3/2+
164Tb 65 99 163.93335(11) 3.0(1) min (5+)
165Tb 65 100 164.93488(21)# 2.11(10) min 3/2+#
166Tb 65 101 165.93799(11) 25.6(22) s
167Tb 65 102 166.94005(43)# 19.4(27) s 3/2+#
168Tb 65 103 167.94364(54)# 8.2(13) s 4-#
169Tb 65 104 168.94622(64)# 2# s 3/2+#
170Tb 65 105 169.95025(75)# 3# s
171Tb 65 106 170.95330(86)# 500# ms 3/2+#

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 gadolinium Isotopes of terbium Isotopes of dysprosium
Index to isotope pages
 
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Isotopes_of_terbium". A list of authors is available in Wikipedia.
Your browser is not current. Microsoft Internet Explorer 6.0 does not support some functions on Chemie.DE