Isotopes of barium

Isotopes of barium (₅₆Ba)
Standard atomic weight Ar°(Ba)
	137.327±0.007; 137.33±0.01 (abridged);
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Naturally occurring barium (₅₆Ba) 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. The only notable exceptions are ¹³³Ba, which has a half-life of 10.51 years, ¹³¹Ba (11.5 days), and ^137mBa (2.55 minutes), which is the decay product of ¹³⁷Cs (30.17 years, and a common fission product).

Barium-114 is predicted to undergo cluster decay, emitting a nucleus of stable ¹²C to produce ¹⁰²Sn. However this decay is not yet observed; the upper limit on the branching ratio of such decay is 0.0034%.

List of isotopes

nuclide symbol	Z(p)	N(n)	isotopic mass (u)	half-life^{[n 1]}	decay mode(s)^[4]^{[n 2]}	daughter isotope(s)^{[n 3]}	nuclear spin and parity	representative isotopic composition (mole fraction)	range of natural variation (mole fraction)
nuclide symbol	excitation energy			half-life^{[n 1]}	decay mode(s)^[4]^{[n 2]}	daughter isotope(s)^{[n 3]}	nuclear spin and parity	representative isotopic composition (mole fraction)	range of natural variation (mole fraction)
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+)#
¹¹⁵Ba	56	59	114.94737(64)#	0.45(5) s	β⁺, p	¹¹⁴Xe	(5/2+)#
¹¹⁶Ba	56	60	115.94138(43)#	1.3(2) s	β⁺	¹¹⁶Cs	0+
¹¹⁶Ba	56	60	115.94138(43)#	1.3(2) s	β⁺, p	¹¹⁵Xe	0+
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+
¹¹⁸Ba	56	62	117.93304(21)#	5.2(2) s	β⁺, p	¹¹⁷Xe	0+
¹¹⁹Ba	56	63	118.93066(21)	5.4(3) s	β⁺	¹¹⁹Cs	(5/2+)
¹¹⁹Ba	56	63	118.93066(21)	5.4(3) s	β⁺, p	¹¹⁸Xe	(5/2+)
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(+)
¹²¹Ba	56	65	120.92405(15)	29.7(15) s	β⁺, p (.02%)	¹²⁰Xe	5/2(+)
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+#
^129mBa	8.42(6) keV			2.16(2) h	IT	¹²⁹Ba	7/2+#
¹³⁰Ba^{[n 5]}	56	74	129.9063208(30)	1.6(±1.1)×10²¹ y	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) y	EC	¹³³Cs	1/2+
^133mBa	288.247(9) keV			38.9(1) h	IT (99.99%)	¹³³Ba	11/2−
^133mBa	288.247(9) keV			38.9(1) h	EC (.0096%)	¹³³Cs	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	IT	¹³⁵Ba	11/2−
¹³⁶Ba	56	80	135.9045759(4)	Stable			0+	0.07854(24)
^136mBa	2030.466(18) keV			308.4(19) ms	IT	¹³⁶Ba	7−
¹³⁷Ba	56	81	136.9058274(5)	Stable			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 7]}	56	82	137.9052472(5)	Stable			0+	0.71698(42)
^138mBa	2090.54(6) keV			800(100) ns			6+
¹³⁹Ba^{[n 7]}	56	83	138.9088413(5)	83.06(28) min	β⁻	¹³⁹La	7/2−
¹⁴⁰Ba^{[n 7]}	56	84	139.910605(9)	12.752(3) d	β⁻	¹⁴⁰La	0+
¹⁴¹Ba^{[n 7]}	56	85	140.914411(9)	18.27(7) min	β⁻	¹⁴¹La	3/2−
¹⁴²Ba^{[n 7]}	56	86	141.916453(7)	10.6(2) min	β⁻	¹⁴²La	0+
¹⁴³Ba^{[n 7]}	56	87	142.920627(14)	14.5(3) s	β⁻	¹⁴³La	5/2−
¹⁴⁴Ba^{[n 7]}	56	88	143.922953(14)	11.5(2) s	β⁻	¹⁴⁴La	0+
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+
¹⁴⁶Ba	56	90	145.93022(8)	2.22(7) s	β⁻, n (.02%)	¹⁴⁵La	0+
¹⁴⁷Ba	56	91	146.93495(22)#	0.893(1) s	β⁻ (99.94%)	¹⁴⁷La	(3/2+)
¹⁴⁷Ba	56	91	146.93495(22)#	0.893(1) s	β⁻, n (.06%)	¹⁴⁶La	(3/2+)
¹⁴⁸Ba	56	92	147.93772(9)	0.612(17) s	β⁻ (99.6%)	¹⁴⁸La	0+
¹⁴⁸Ba	56	92	147.93772(9)	0.612(17) s	β⁻, n (.4%)	¹⁴⁷La	0+
¹⁴⁹Ba	56	93	148.94258(21)#	344(7) ms	β⁻ (99.57%)	¹⁴⁹La	3/2−#
¹⁴⁹Ba	56	93	148.94258(21)#	344(7) ms	β⁻, n (.43%)	¹⁴⁸La	3/2−#
¹⁵⁰Ba	56	94	149.94568(43)#	300 ms	β⁻	¹⁵⁰La	0+
¹⁵⁰Ba	56	94	149.94568(43)#	300 ms	β⁻, n (rare)	¹⁴⁹La	0+
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)
^ Cluster decay is predicted but had never been observed.
^ Primordial radioisotope
^ Believed to undergo β⁺β⁺ decay to ¹³²Xe with a half-life over 300×10¹⁸ years
^ ^a ^b ^c ^d ^e ^f ^g 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

^ Kondev, F. G.; Wang, M.; Huang, W. J.; Naimi, S.; Audi, G. (2021). "The NUBASE2020 evaluation of nuclear properties" (PDF). Chinese Physics C. 45 (3): 030001. doi:10.1088/1674-1137/abddae.
^ "Standard Atomic Weights: Barium". CIAAW. 1985.
^ Prohaska, Thomas; Irrgeher, Johanna; Benefield, Jacqueline; Böhlke, John K.; Chesson, Lesley A.; Coplen, Tyler B.; Ding, Tiping; Dunn, Philip J. H.; Gröning, Manfred; Holden, Norman E.; Meijer, Harro A. J. (2022-05-04). "Standard atomic weights of the elements 2021 (IUPAC Technical Report)". Pure and Applied Chemistry. doi:10.1515/pac-2019-0603. ISSN 1365-3075.
^ "Universal Nuclide Chart". nucleonica. {{cite web}}: Unknown parameter |registration= ignored (|url-access= suggested) (help)

Isotope masses from:
- G. Audi; A. H. Wapstra; C. Thibault; J. Blachot; O. Bersillon (2003). "The NUBASE evaluation of nuclear and decay properties" (PDF). Nuclear Physics A. 729: 3–128. Bibcode:2003NuPhA.729....3A. doi:10.1016/j.nuclphysa.2003.11.001. Archived from the original (PDF) on 2008-09-23. {{cite journal}}: Unknown parameter |deadurl= ignored (|url-status= suggested) (help)
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; 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. {{cite journal}}: Unknown parameter |laysummary= ignored (help)
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; O. Bersillon (2003). "The NUBASE evaluation of nuclear and decay properties" (PDF). Nuclear Physics A. 729: 3–128. Bibcode:2003NuPhA.729....3A. doi:10.1016/j.nuclphysa.2003.11.001. Archived from the original (PDF) on 2008-09-23. {{cite journal}}: Unknown parameter |deadurl= ignored (|url-status= suggested) (help)
- National Nuclear Data Center. "NuDat 2.1 database". Brookhaven National Laboratory. Retrieved September 2005. {{cite web}}: Check date values in: |accessdate= (help)
- N. E. Holden (2004). "Table of the Isotopes". In D. R. Lide (ed.). CRC Handbook of Chemistry and Physics (85th ed.). CRC Press. Section 11. ISBN 978-0-8493-0485-9. {{cite book}}: Unknown parameter |nopp= ignored (|no-pp= suggested) (help)
Half-life of ¹³⁰Ba from:
- A. P. Meshik; C. M. Hohenberg; O. V. Pravdivtseva; 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; 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.

[4] Bold for isotopes with half-lives longer than the age of the universe (nearly stable)

[6] Abbreviations:
CD: Cluster decay
EC: Electron capture
IT: Isomeric transition

[7] Bold for stable isotopes, bold italics for nearly-stable isotopes (half-life longer than the age of the universe)

[8] Cluster decay is predicted but had never been observed.

[9] Primordial radioisotope

[10] Believed to undergo β⁺β⁺ decay to ¹³²Xe with a half-life over 300×10¹⁸ years

[FP-11] ^ ^a ^b ^c ^d ^e ^f ^g Fission product

[NUBASE2020-1] Kondev, F. G.; Wang, M.; Huang, W. J.; Naimi, S.; Audi, G. (2021). "The NUBASE2020 evaluation of nuclear properties" (PDF). Chinese Physics C. 45 (3): 030001. doi:10.1088/1674-1137/abddae.

[2] "Standard Atomic Weights: Barium". CIAAW. 1985.

[CIAAW2021-3] Prohaska, Thomas; Irrgeher, Johanna; Benefield, Jacqueline; Böhlke, John K.; Chesson, Lesley A.; Coplen, Tyler B.; Ding, Tiping; Dunn, Philip J. H.; Gröning, Manfred; Holden, Norman E.; Meijer, Harro A. J. (2022-05-04). "Standard atomic weights of the elements 2021 (IUPAC Technical Report)". Pure and Applied Chemistry. doi:10.1515/pac-2019-0603. ISSN 1365-3075.

[5] "Universal Nuclide Chart". nucleonica. {{cite web}}: Unknown parameter |registration= ignored (|url-access= suggested) (help)

[1]

[2]

[3]

[n 1]

[4]

[n 2]

[n 3]

[n 4]

[n 5]

[n 6]

[n 7]

List of isotopes

Notes

See also

References