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Isotopes of barium



Naturally occurring Barium (Ba) is a mix of seven stable isotopes. There are twenty-two isotopes known, but most of these are highly radioactive and have half-lives in the several millisecond to several minute range. The only notable exceptions are 133Ba which has a half-life of 10.51 years, and 137mBa (2.55 minutes).

Additional recommended knowledge


Standard atomic mass: 137.327(7) 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
114Ba 56 58 113.95068(15) 530(230) ms [0.43(+30-15) s] 0+
115Ba 56 59 114.94737(64)# 0.45(5) s (5/2+)#
116Ba 56 60 115.94138(43)# 1.3(2) s 0+
117Ba 56 61 116.93850(32)# 1.75(7) s (3/2)(+#)
118Ba 56 62 117.93304(21)# 5.2(2) s 0+
119Ba 56 63 118.93066(21) 5.4(3) s (5/2+)
120Ba 56 64 119.92604(32) 24(2) s 0+
121Ba 56 65 120.92405(15) 29.7(15) s 5/2(+)
122Ba 56 66 121.91990(3) 1.95(15) min 0+
123Ba 56 67 122.918781(13) 2.7(4) min 5/2(+)
124Ba 56 68 123.915094(13) 11.0(5) min 0+
125Ba 56 69 124.914473(12) 3.5(4) min 1/2(+#)
126Ba 56 70 125.911250(13) 100(2) min 0+
127Ba 56 71 126.911094(12) 12.7(4) min 1/2+
127mBa 80.33(12) keV 1.9(2) s 7/2-
128Ba 56 72 127.908318(11) 2.43(5) d 0+
129Ba 56 73 128.908679(12) 2.23(11) h 1/2+
129mBa 8.42(6) keV 2.16(2) h 7/2+#
130Ba 56 74 129.9063208(30) STABLE [>4.0E+21 a] 0+ 0.00106(1)
130mBa 2475.12(18) keV 9.54(14) ms 8-
131Ba 56 75 130.906941(3) 11.50(6) d 1/2+
131mBa 187.14(12) keV 14.6(2) min 9/2-
132Ba 56 76 131.9050613(11) STABLE [>300E+18 a] 0+ 0.00101(1)
133Ba 56 77 132.9060075(11) 10.51(5) a 1/2+
133mBa 288.247(9) keV 38.9(1) h 11/2-
134Ba 56 78 133.9045084(4) STABLE 0+ 0.02417(18)
135Ba 56 79 134.9056886(4) STABLE 3/2+ 0.06592(12)
135mBa 268.22(2) keV 28.7(2) h 11/2-
136Ba 56 80 135.9045759(4) STABLE 0+ 0.07854(24)
136mBa 2030.466(18) keV 308.4(19) ms 7-
137Ba 56 81 136.9058274(5) STABLE 3/2+ 0.11232(24)
137m1Ba 661.659(3) keV 2.552(1) min 11/2-
137m2Ba 2349.1(4) keV 0.59(10) µs (17/2-)
138Ba 56 82 137.9052472(5) STABLE 0+ 0.71698(42)
138mBa 2090.54(6) keV 800(100) ns 6+
139Ba 56 83 138.9088413(5) 83.06(28) min 7/2-
140Ba 56 84 139.910605(9) 12.752(3) d 0+
141Ba 56 85 140.914411(9) 18.27(7) min 3/2-
142Ba 56 86 141.916453(7) 10.6(2) min 0+
143Ba 56 87 142.920627(14) 14.5(3) s 5/2-
144Ba 56 88 143.922953(14) 11.5(2) s 0+
145Ba 56 89 144.92763(8) 4.31(16) s 5/2-
146Ba 56 90 145.93022(8) 2.22(7) s 0+
147Ba 56 91 146.93495(22)# 0.893(1) s (3/2+)
148Ba 56 92 147.93772(9) 0.612(17) s 0+
149Ba 56 93 148.94258(21)# 344(7) ms 3/2-#
150Ba 56 94 149.94568(43)# 300 ms 0+
151Ba 56 95 150.95081(43)# 200# ms [>300 ns] 3/2-#
152Ba 56 96 151.95427(54)# 100# ms 0+
153Ba 56 97 152.95961(86)# 80# ms 5/2-#

Notes

  • Geologically exceptional samples are known in which the isotopic composition lies outside the reported range. The uncertainty in the atomic mass may exceed the stated value for such specimens.
  • 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 caesium Isotopes of barium Isotopes of lanthanum
Index to isotope pages
 
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Isotopes_of_barium". A list of authors is available in Wikipedia.
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