Isotopes of barium
Naturally occurring barium (Ba) is a mix of six stable isotopes and one very long-lived radioactive primordial isotope, barium-130, recently identified as being unstable by geochemical means (from analysis of the presence of its daughter xenon-130 in rocks). This nuclide decays by double-electron capture (absorbing two electrons and emitting two neutrinos) with a half-life of (0.5-2.7)×1021 years (about 1011 times the age of the universe).
There are a total of thirty-three known radioisotopes in addition to 130Ba, but most of these are highly radioactive with half-lives in the several millisecond to several minute range. and thus never encountered in nature. The only notable exceptions are 133Ba which has a half-life of 10.51 years, and 137mBa (2.55 minutes), which is the decay product of 137Cs (30.17 years, and a common fission product).
Barium-114 is the lightest nuclide known to undergo cluster decay, emitting a nucleus of stable 12C to produce 102Sn in .0034% of decays.
Standard atomic mass: 137.327(7) u
112Ba is the heaviest known atom with equal numbers protons and neutrons. 108Xe is the second-heaviest.
Table
| nuclide symbol |
Z(p) | N(n) | isotopic mass (u) |
half-life[n 1] | decay mode(s)[1][n 2] |
daughter isotope(s)[n 3] |
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] |
β+, p (99.59%) | 113Xe | 0+ | ||
| α (.37%) | 110Xe | ||||||||
| β+ (.04%) | 114Cs | ||||||||
| CD (.0034%)[n 4] | 102Sn, 12C | ||||||||
| 115Ba | 56 | 59 | 114.94737(64)# | 0.45(5) s | β+ | 115Cs | (5/2+)# | ||
| β+, p | 114Xe | ||||||||
| 116Ba | 56 | 60 | 115.94138(43)# | 1.3(2) s | β+ | 116Cs | 0+ | ||
| β+, p | 115Xe | ||||||||
| 117Ba | 56 | 61 | 116.93850(32)# | 1.75(7) s | β+ | 117Cs | (3/2)(+#) | ||
| β+, α | 113I | ||||||||
| β+, p | 116Xe | ||||||||
| 118Ba | 56 | 62 | 117.93304(21)# | 5.2(2) s | β+ | 118Cs | 0+ | ||
| β+, p | 117Xe | ||||||||
| 119Ba | 56 | 63 | 118.93066(21) | 5.4(3) s | β+ | 119Cs | (5/2+) | ||
| β+, p | 118Xe | ||||||||
| 120Ba | 56 | 64 | 119.92604(32) | 24(2) s | β+ | 120Cs | 0+ | ||
| 121Ba | 56 | 65 | 120.92405(15) | 29.7(15) s | β+ (99.98%) | 121Cs | 5/2(+) | ||
| β+, p (.02%) | 120Xe | ||||||||
| 122Ba | 56 | 66 | 121.91990(3) | 1.95(15) min | β+ | 122Cs | 0+ | ||
| 123Ba | 56 | 67 | 122.918781(13) | 2.7(4) min | β+ | 123Cs | 5/2(+) | ||
| 124Ba | 56 | 68 | 123.915094(13) | 11.0(5) min | β+ | 124Cs | 0+ | ||
| 125Ba | 56 | 69 | 124.914473(12) | 3.5(4) min | β+ | 125Cs | 1/2(+#) | ||
| 126Ba | 56 | 70 | 125.911250(13) | 100(2) min | β+ | 126Cs | 0+ | ||
| 127Ba | 56 | 71 | 126.911094(12) | 12.7(4) min | β+ | 127Cs | 1/2+ | ||
| 127mBa | 80.33(12) keV | 1.9(2) s | IT | 127Ba | 7/2− | ||||
| 128Ba | 56 | 72 | 127.908318(11) | 2.43(5) d | β+ | 128Cs | 0+ | ||
| 129Ba | 56 | 73 | 128.908679(12) | 2.23(11) h | β+ | 129Cs | 1/2+ | ||
| 129mBa | 8.42(6) keV | 2.16(2) h | β+ | 129Cs | 7/2+# | ||||
| IT | 129Ba | ||||||||
| 130Ba[n 5] | 56 | 74 | 129.9063208(30) | (0.5-2.7)×1021 yrs | Double EC | 130Xe | 0+ | 0.00106(1) | |
| 130mBa | 2475.12(18) keV | 9.54(14) ms | IT | 130Ba | 8− | ||||
| 131Ba | 56 | 75 | 130.906941(3) | 11.50(6) d | β+ | 131Cs | 1/2+ | ||
| 131mBa | 187.14(12) keV | 14.6(2) min | IT | 131Ba | 9/2− | ||||
| 132Ba | 56 | 76 | 131.9050613(11) | Observationally Stable[n 6] | 0+ | 0.00101(1) | |||
| 133Ba | 56 | 77 | 132.9060075(11) | 10.51(5) yrs | EC | 133Cs | 1/2+ | ||
| 133mBa | 288.247(9) keV | 38.9(1) h | IT (99.99%) | 133Ba | 11/2− | ||||
| EC (.0096%) | 133Cs | ||||||||
| 134Ba | 56 | 78 | 133.9045084(4) | Stable[n 7] | 0+ | 0.02417(18) | |||
| 135Ba | 56 | 79 | 134.9056886(4) | Stable[n 7] | 3/2+ | 0.06592(12) | |||
| 135mBa | 268.22(2) keV | 28.7(2) h | IT | 135Ba | 11/2− | ||||
| 136Ba | 56 | 80 | 135.9045759(4) | Stable[n 7] | 0+ | 0.07854(24) | |||
| 136mBa | 2030.466(18) keV | 308.4(19) ms | IT | 136Ba | 7− | ||||
| 137Ba | 56 | 81 | 136.9058274(5) | Stable[n 7] | 3/2+ | 0.11232(24) | |||
| 137m1Ba | 661.659(3) keV | 2.552(1) min | IT | 137Ba | 11/2− | ||||
| 137m2Ba | 2349.1(4) keV | 0.59(10) µs | (17/2−) | ||||||
| 138Ba[n 8] | 56 | 82 | 137.9052472(5) | Stable[n 7] | 0+ | 0.71698(42) | |||
| 138mBa | 2090.54(6) keV | 800(100) ns | 6+ | ||||||
| 139Ba[n 8] | 56 | 83 | 138.9088413(5) | 83.06(28) min | β- | 139La | 7/2− | ||
| 140Ba[n 8] | 56 | 84 | 139.910605(9) | 12.752(3) d | β- | 140La | 0+ | ||
| 141Ba | 56 | 85 | 140.914411(9) | 18.27(7) min | β- | 141La | 3/2− | ||
| 142Ba | 56 | 86 | 141.916453(7) | 10.6(2) min | β- | 142La | 0+ | ||
| 143Ba | 56 | 87 | 142.920627(14) | 14.5(3) s | β- | 143La | 5/2− | ||
| 144Ba | 56 | 88 | 143.922953(14) | 11.5(2) s | β- (96.4%) | 144La | 0+ | ||
| β+ (3.59%) | 144Cs | ||||||||
| 145Ba | 56 | 89 | 144.92763(8) | 4.31(16) s | β- | 145La | 5/2− | ||
| 146Ba | 56 | 90 | 145.93022(8) | 2.22(7) s | β- (99.98%) | 146La | 0+ | ||
| β-, n (.02%) | 145La | ||||||||
| 147Ba | 56 | 91 | 146.93495(22)# | 0.893(1) s | β- (99.94%) | 147La | (3/2+) | ||
| β-, n (.06%) | 146La | ||||||||
| 148Ba | 56 | 92 | 147.93772(9) | 0.612(17) s | β- (99.6%) | 148La | 0+ | ||
| β-, n (.4%) | 147La | ||||||||
| 149Ba | 56 | 93 | 148.94258(21)# | 344(7) ms | β- (99.57%) | 149La | 3/2−# | ||
| β-, n (.43%) | 148La | ||||||||
| 150Ba | 56 | 94 | 149.94568(43)# | 300 ms | β- | 150La | 0+ | ||
| β-, n (rare) | 149La | ||||||||
| 151Ba | 56 | 95 | 150.95081(43)# | 200# ms [>300 ns] | β- | 151La | 3/2−# | ||
| 152Ba | 56 | 96 | 151.95427(54)# | 100# ms | β- | 152La | 0+ | ||
| 153Ba | 56 | 97 | 152.95961(86)# | 80# ms | β- | 153La | 5/2−# | ||
- ^ Bold for isotopes with half-lives longer than the age of the universe (nearly stable)
- ^ Abbreviations:
CD: Cluster decay
EC: Electron capture
IT: Isomeric transition - ^ Bold for stable isotopes, bold italics for nearly-stable isotopes (half-life longer than the age of the universe)
- ^ Lightest nuclide known to undergo cluster decay
- ^ Primordial radioisotope
- ^ Believed to undergo β+β+ decay to 132Xe with a half-life over 300×1018 years
- ^ a b c d e Theoretically capable of spontaneous fission
- ^ a b c Fission product
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:
- G. Audi, A. H. Wapstra, C. Thibault, J. Blachot and O. Bersillon (2003). "The NUBASE evaluation of nuclear and decay properties". Nuclear Physics A 729: 3–128. Bibcode:2003NuPhA.729....3A. doi:10.1016/j.nuclphysa.2003.11.001.
- Isotopic compositions and standard atomic masses from:
- J. R. de Laeter, J. K. Böhlke, P. De Bièvre, H. Hidaka, H. S. Peiser, K. J. R. Rosman and P. D. P. Taylor (2003). "Atomic weights of the elements. Review 2000 (IUPAC Technical Report)". Pure and Applied Chemistry 75 (6): 683–800. doi:10.1351/pac200375060683.
- M. E. Wieser (2006). "Atomic weights of the elements 2005 (IUPAC Technical Report)". Pure and Applied Chemistry 78 (11): 2051–2066. doi:10.1351/pac200678112051. Lay summary.
- Half-life, spin, and isomer data selected from the following sources. See editing notes on this article's talk page.
- G. Audi, A. H. Wapstra, C. Thibault, J. Blachot and O. Bersillon (2003). "The NUBASE evaluation of nuclear and decay properties". Nuclear Physics A 729: 3–128. Bibcode:2003NuPhA.729....3A. doi:10.1016/j.nuclphysa.2003.11.001.
- National Nuclear Data Center. "NuDat 2.1 database". Brookhaven National Laboratory. Retrieved September 2005.
- N. E. Holden (2004). "Table of the Isotopes". In D. R. Lide. CRC Handbook of Chemistry and Physics (85th ed.). CRC Press. Section 11. ISBN 978-0-8493-0485-9.
- Half-life of 130Ba from:
- A. P. Meshik, C.M. Hohenberg, O.V. Pravdivtseva, and Ya.S. Kapusta (2001). "Weak decay of 130Ba and 132Ba: Geochemical measurements". Physical Review C 64 (3): 035205 [6 pages]. Bibcode:2001PhRvC..64c5205M. doi:10.1103/PhysRevC.64.035205.
- M. Pujol, B. Marty, P. Burnard and P. Philippot (2009). "Xenon in Archean barite: Weak decay of 130Ba, mass-dependent isotopic fractionation and implication for barite formation". Geochimica et Cosmochimica Acta 73 (22): 6834–6846. Bibcode:2009GeCoA..73.6834P. doi:10.1016/j.gca.2009.08.002.
| Isotopes of caesium | Isotopes of barium | Isotopes of lanthanum |
| Table of nuclides | ||
| Isotopes of the chemical elements | |||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 H |
2 He |
||||||||||||||||
| 3 Li |
4 Be |
5 B |
6 C |
7 N |
8 O |
9 F |
10 Ne |
||||||||||
| 11 Na |
12 Mg |
13 Al |
14 Si |
15 P |
16 S |
17 Cl |
18 Ar |
||||||||||
| 19 K |
20 Ca |
21 Sc |
22 Ti |
23 V |
24 Cr |
25 Mn |
26 Fe |
27 Co |
28 Ni |
29 Cu |
30 Zn |
31 Ga |
32 Ge |
33 As |
34 Se |
35 Br |
36 Kr |
| 37 Rb |
38 Sr |
39 Y |
40 Zr |
41 Nb |
42 Mo |
43 Tc |
44 Ru |
45 Rh |
46 Pd |
47 Ag |
48 Cd |
49 In |
50 Sn |
51 Sb |
52 Te |
53 I |
54 Xe |
| 55 Cs |
56 Ba |
* | 72 Hf |
73 Ta |
74 W |
75 Re |
76 Os |
77 Ir |
78 Pt |
79 Au |
80 Hg |
81 Tl |
82 Pb |
83 Bi |
84 Po |
85 At |
86 Rn |
| 87 Fr |
88 Ra |
** | 104 Rf |
105 Db |
106 Sg |
107 Bh |
108 Hs |
109 Mt |
110 Ds |
111 Rg |
112 Cn |
113 Uut |
114 Fl |
115 Uup |
116 Lv |
117 Uus |
118 Uuo |
| * | 57 La |
58 Ce |
59 Pr |
60 Nd |
61 Pm |
62 Sm |
63 Eu |
64 Gd |
65 Tb |
66 Dy |
67 Ho |
68 Er |
69 Tm |
70 Yb |
71 Lu |
||
| ** | 89 Ac |
90 Th |
91 Pa |
92 U |
93 Np |
94 Pu |
95 Am |
96 Cm |
97 Bk |
98 Cf |
99 Es |
100 Fm |
101 Md |
102 No |
103 Lr |
||
