Isotopes of barium

Isotopes of barium (₅₆Ba)
Standard atomic weight Ar°(Ba)
	137.327±0.007; 137.33±0.01 (abridged);
	view ; talk ; edit ;

Last updated May 15, 2024

Naturally occurring barium (₅₆Ba) is a mix of six stable isotopes and one very long-lived radioactive primordial isotope, barium-130, identified as being unstable by geochemical means (from analysis of the presence of its daughter xenon-130 in rocks) in 2001.^[4] 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. The longest-lived of these is ¹³³Ba, which has a half-life of 10.51 years. All other radioisotopes have half-lives shorter than two weeks. The longest-lived isomer is ^133mBa, which has a half-life of 38.9 hours. The shorter-lived ^137mBa (half-life 2.55 minutes) arises as the decay product of the common fission product caesium-137.

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 ^{[n 1]}	Z	N	Isotopic mass (Da)^[5] ^{[n 2]}^{[n 3]}	Half-life	Decay mode ^{[n 4]}	Daughter isotope ^{[n 5]}^{[n 6]}	Spin and parity ^{[n 7]}^{[n 8]}	Natural abundance (mole fraction)
Nuclide ^{[n 1]}	Excitation energy			Half-life	Decay mode ^{[n 4]}	Daughter isotope ^{[n 5]}^{[n 6]}	Spin and parity ^{[n 7]}^{[n 8]}	Normal proportion	Range of variation
¹¹⁴Ba	56	58	113.95072(11)	530(230) ms [0.43(+30−15) s]	β⁺, p (99.59%)	¹¹³Xe	0+
					α (.37%)	¹¹⁰Xe
					β⁺ (.04%)	¹¹⁴Cs
					CD (<.0034%)^{[n 9]}	¹⁰²Sn, ¹²C
¹¹⁵Ba	56	59	114.94748(22)#	0.45(5) s	β⁺	¹¹⁵Cs	(5/2+)#
¹¹⁵Ba	56	59	114.94748(22)#	0.45(5) s	β⁺, p	¹¹⁴Xe	(5/2+)#
¹¹⁶Ba	56	60	115.94162(22)#	1.3(2) s	β⁺	¹¹⁶Cs	0+
¹¹⁶Ba	56	60	115.94162(22)#	1.3(2) s	β⁺, p	¹¹⁵Xe	0+
¹¹⁷Ba	56	61	116.93832(27)	1.75(7) s	β⁺	¹¹⁷Cs	(3/2)(+#)
					β⁺, α	¹¹³I
					β⁺, p	¹¹⁶Xe
¹¹⁸Ba	56	62	117.93323(22)#	5.2(2) s	β⁺	¹¹⁸Cs	0+
¹¹⁸Ba	56	62	117.93323(22)#	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	124.914472(12)	3.5(4) min	β⁺	¹²⁵Cs	1/2(+#)
¹²⁶Ba	56	70	125.911250(13)	100(2) min	β⁺	¹²⁶Cs	0+
¹²⁷Ba	56	71	126.911091(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	127.9083524(17)	2.43(5) d	β⁺	¹²⁸Cs	0+
¹²⁹Ba	56	73	128.908683(11)	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 10]}	56	74	129.9063260(3)	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	130.9069463(4)	11.50(6) d	β⁺	¹³¹Cs	1/2+
^131mBa	187.14(12) keV			14.6(2) min	IT	¹³¹Ba	9/2−
¹³²Ba	56	76	131.9050612(11)	Observationally Stable ^{[n 11]}			0+	0.00101(1)
¹³³Ba	56	77	132.9060074(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	133.90450825(27)	Stable			0+	0.02417(18)
¹³⁵Ba	56	79	134.90568845(26)	Stable			3/2+	0.06592(12)
^135mBa	268.22(2) keV			28.7(2) h	IT	¹³⁵Ba	11/2−
¹³⁶Ba	56	80	135.90457580(26)	Stable			0+	0.07854(24)
^136mBa	2030.466(18) keV			308.4(19) ms	IT	¹³⁶Ba	7−
¹³⁷Ba	56	81	136.90582721(27)	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 12]}	56	82	137.90524706(27)	Stable			0+	0.71698(42)
^138mBa	2090.54(6) keV			800(100) ns			6+
¹³⁹Ba^{[n 12]}	56	83	138.90884116(27)	83.06(28) min	β⁻	¹³⁹La	7/2−
¹⁴⁰Ba^{[n 12]}	56	84	139.910608(8)	12.752(3) d	β⁻	¹⁴⁰La	0+
¹⁴¹Ba^{[n 12]}	56	85	140.914404(6)	18.27(7) min	β⁻	¹⁴¹La	3/2−
¹⁴²Ba^{[n 12]}	56	86	141.916433(6)	10.6(2) min	β⁻	¹⁴²La	0+
¹⁴³Ba^{[n 12]}	56	87	142.920625(7)	14.5(3) s	β⁻	¹⁴³La	5/2−
¹⁴⁴Ba^{[n 12]}	56	88	143.922955(8)	11.5(2) s	β⁻	¹⁴⁴La	0+
¹⁴⁵Ba	56	89	144.927518(9)	4.31(16) s	β⁻	¹⁴⁵La	5/2−
¹⁴⁶Ba	56	90	145.9303632(19)	2.22(7) s	β⁻ (99.98%)	¹⁴⁶La	0+
¹⁴⁶Ba	56	90	145.9303632(19)	2.22(7) s	β⁻, n (.02%)	¹⁴⁵La	0+
¹⁴⁷Ba	56	91	146.935304(21)	0.893(1) s	β⁻ (99.94%)	¹⁴⁷La	(3/2+)
¹⁴⁷Ba	56	91	146.935304(21)	0.893(1) s	β⁻, n (.06%)	¹⁴⁶La	(3/2+)
¹⁴⁸Ba	56	92	147.9382230(16)	0.612(17) s	β⁻ (99.6%)	¹⁴⁸La	0+
¹⁴⁸Ba	56	92	147.9382230(16)	0.612(17) s	β⁻, n (.4%)	¹⁴⁷La	0+
¹⁴⁹Ba	56	93	148.9432840(27)	344(7) ms	β⁻ (99.57%)	¹⁴⁹La	3/2−#
¹⁴⁹Ba	56	93	148.9432840(27)	344(7) ms	β⁻, n (.43%)	¹⁴⁸La	3/2−#
¹⁵⁰Ba	56	94	149.946441(6)	300 ms	β⁻	¹⁵⁰La	0+
¹⁵⁰Ba	56	94	149.946441(6)	300 ms	β⁻, n (rare)	¹⁴⁹La	0+
¹⁵¹Ba	56	95	150.95176(43)#	200# ms [>300 ns]	β⁻	¹⁵¹La	3/2−#
¹⁵²Ba	56	96	151.95533(43)#	100# ms	β⁻	¹⁵²La	0+
¹⁵³Ba	56	97	152.96085(43)#	80# ms	β⁻	¹⁵³La	5/2−#
¹⁵⁴Ba	56	98	153.96466(54)#	53(48) ms	β⁻	¹⁵⁴La	0+
This table header & footer: view

↑ ^mBa – Excited nuclear isomer.
↑ ( ) – Uncertainty (1σ) is given in concise form in parentheses after the corresponding last digits.
↑ # – Atomic mass marked #: value and uncertainty derived not from purely experimental data, but at least partly from trends from the Mass Surface (TMS).
↑ Modes of decay:
CD: Cluster decay
EC: Electron capture
IT: Isomeric transition
n: Neutron emission
p: Proton emission
↑ Bold italics symbol as daughter – Daughter product is nearly stable.
↑ Bold symbol as daughter – Daughter product is stable.
↑ ( ) spin value – Indicates spin with weak assignment arguments.
↑ # – Values marked # are not purely derived from experimental data, but at least partly from trends of neighboring nuclides (TNN).
↑ 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
1 2 3 4 5 6 7 Fission product

Related Research Articles

Protactinium (₉₁Pa) has no stable isotopes. The four naturally occurring isotopes allow a standard atomic weight to be given.

There are seven stable isotopes of mercury (₈₀Hg) with ²⁰²Hg being the most abundant (29.86%). The longest-lived radioisotopes are ¹⁹⁴Hg with a half-life of 444 years, and ²⁰³Hg with a half-life of 46.612 days. Most of the remaining 40 radioisotopes have half-lives that are less than a day. ¹⁹⁹Hg and ²⁰¹Hg are the most often studied NMR-active nuclei, having spin quantum numbers of 1/2 and 3/2 respectively. All isotopes of mercury are either radioactive or observationally stable, meaning that they are predicted to be radioactive but no actual decay has been observed. These isotopes are predicted to undergo either alpha decay or double beta decay.

Naturally occurring platinum (₇₈Pt) consists of five stable isotopes (¹⁹²Pt, ¹⁹⁴Pt, ¹⁹⁵Pt, ¹⁹⁶Pt, ¹⁹⁸Pt) and one very long-lived (half-life 4.83×10¹¹ years) radioisotope (¹⁹⁰Pt). There are also 34 known synthetic radioisotopes, the longest-lived of which is ¹⁹³Pt with a half-life of 50 years. All other isotopes have half-lives under a year, most under a day. All isotopes of platinum are either radioactive or observationally stable, meaning that they are predicted to be radioactive but no actual decay has been observed. Platinum-195 is the most abundant isotope.

Naturally occurring tungsten (₇₄W) consists of five isotopes. Four are considered stable (¹⁸²W, ¹⁸³W, ¹⁸⁴W, and ¹⁸⁶W) and one is slightly radioactive, ¹⁸⁰W, with an extremely long half-life of 1.8 ± 0.2 exayears (10¹⁸ years). On average, two alpha decays of ¹⁸⁰W occur per gram of natural tungsten per year, so for most practical purposes, ¹⁸⁰W can be considered stable. Theoretically, all five can decay into isotopes of element 72 (hafnium) by alpha emission, but only ¹⁸⁰W has been observed to do so. The other naturally occurring isotopes have not been observed to decay (they are observationally stable), and lower bounds for their half-lives have been established:

Natural hafnium (₇₂Hf) consists of five observationally stable isotopes (¹⁷⁶Hf, ¹⁷⁷Hf, ¹⁷⁸Hf, ¹⁷⁹Hf, and ¹⁸⁰Hf) and one very long-lived radioisotope, ¹⁷⁴Hf, with a half-life of 7.0×10¹⁶ years. In addition, there are 34 known synthetic radioisotopes, the most stable of which is ¹⁸²Hf with a half-life of 8.9×10⁶ years. This extinct radionuclide is used in hafnium–tungsten dating to study the chronology of planetary differentiation.

Naturally occurring lutetium (₇₁Lu) is composed of one stable isotope ¹⁷⁵Lu (97.41% natural abundance) and one long-lived radioisotope, ¹⁷⁶Lu with a half-life of 3.78 × 10¹⁰ years (2.59% natural abundance). Forty radioisotopes have been characterized, with the most stable, besides ¹⁷⁶Lu, being ¹⁷⁴Lu with a half-life of 3.31 years, and ¹⁷³Lu with a half-life of 1.37 years. All of the remaining radioactive isotopes have half-lives that are less than 9 days, and the majority of these have half-lives that are less than half an hour. This element also has 18 meta states, with the most stable being ^177mLu (t_1/2 160.4 days), ^174mLu (t_1/2 142 days) and ^178mLu (t_1/2 23.1 minutes).

Naturally occurring ytterbium (₇₀Yb) is composed of seven stable isotopes: ¹⁶⁸Yb, ¹⁷⁰Yb–¹⁷⁴Yb, and ¹⁷⁶Yb, with ¹⁷⁴Yb being the most abundant. 30 radioisotopes have been characterized, with the most stable being ¹⁶⁹Yb with a half-life of 32.014 days, ¹⁷⁵Yb with a half-life of 4.185 days, and ¹⁶⁶Yb with a half-life of 56.7 hours. All of the remaining radioactive isotopes have half-lives that are less than 2 hours, and the majority of these have half-lives that are less than 20 minutes. This element also has 18 meta states, with the most stable being ^169mYb.

Naturally occurring terbium (₆₅Tb) is composed of one stable isotope, ¹⁵⁹Tb. Thirty-seven radioisotopes have been characterized, with the most stable being ¹⁵⁸Tb with a half-life of 180 years, ¹⁵⁷Tb with a half-life of 71 years, and ¹⁶⁰Tb with a half-life of 72.3 days. All of the remaining radioactive isotopes have half-lives that are less than 6.907 days, and the majority of these have half-lives that are less than 24 seconds. This element also has 27 meta states, with the most stable being ^156m1Tb, ^154m2Tb and ^154m1Tb.

Naturally occurring cerium (₅₈Ce) is composed of 4 stable isotopes: ¹³⁶Ce, ¹³⁸Ce, ¹⁴⁰Ce, and ¹⁴²Ce, with ¹⁴⁰Ce being the most abundant and the only one theoretically stable; ¹³⁶Ce, ¹³⁸Ce, and ¹⁴²Ce are predicted to undergo double beta decay but this process has never been observed. There are 35 radioisotopes that have been characterized, with the most stable being ¹⁴⁴Ce, with a half-life of 284.893 days; ¹³⁹Ce, with a half-life of 137.640 days and ¹⁴¹Ce, with a half-life of 32.501 days. All of the remaining radioactive isotopes have half-lives that are less than 4 days and the majority of these have half-lives that are less than 10 minutes. This element also has 10 meta states.

Naturally occurring lanthanum (₅₇La) is composed of one stable (¹³⁹La) and one radioactive (¹³⁸La) isotope, with the stable isotope, ¹³⁹La, being the most abundant (99.91% natural abundance). There are 39 radioisotopes that have been characterized, with the most stable being ¹³⁸La, with a half-life of 1.02×10¹¹ years; ¹³⁷La, with a half-life of 60,000 years and ¹⁴⁰La, with a half-life of 1.6781 days. The remaining radioactive isotopes have half-lives that are less than a day and the majority of these have half-lives that are less than 1 minute. This element also has 12 nuclear isomers, the longest-lived of which is ^132mLa, with a half-life of 24.3 minutes. Lighter isotopes mostly decay to isotopes of barium and heavy ones mostly decay to isotopes of cerium. ¹³⁸La can decay to both.

Tin (₅₀Sn) is the element with the greatest number of stable isotopes. This is probably related to the fact that 50 is a "magic number" of protons. In addition, twenty-nine unstable tin isotopes are known, including tin-100 (¹⁰⁰Sn) and tin-132 (¹³²Sn), which are both "doubly magic". The longest-lived tin radioisotope is tin-126 (¹²⁶Sn), with a half-life of 230,000 years. The other 28 radioisotopes have half-lives of less than a year.

Indium (₄₉In) consists of two primordial nuclides, with the most common (~ 95.7%) nuclide (¹¹⁵In) being measurably though weakly radioactive. Its spin-forbidden decay has a half-life of 4.41×10¹⁴ years, much longer than the currently accepted age of the Universe.

Natural palladium (₄₆Pd) is composed of six stable isotopes, ¹⁰²Pd, ¹⁰⁴Pd, ¹⁰⁵Pd, ¹⁰⁶Pd, ¹⁰⁸Pd, and ¹¹⁰Pd, although ¹⁰²Pd and ¹¹⁰Pd are theoretically unstable. The most stable radioisotopes are ¹⁰⁷Pd with a half-life of 6.5 million years, ¹⁰³Pd with a half-life of 17 days, and ¹⁰⁰Pd with a half-life of 3.63 days. Twenty-three other radioisotopes have been characterized with atomic weights ranging from 90.949 u (⁹¹Pd) to 128.96 u (¹²⁹Pd). Most of these have half-lives that are less than a half an hour except ¹⁰¹Pd, ¹⁰⁹Pd, and ¹¹²Pd.

The alkaline earth metal strontium (₃₈Sr) has four stable, naturally occurring isotopes: ⁸⁴Sr (0.56%), ⁸⁶Sr (9.86%), ⁸⁷Sr (7.0%) and ⁸⁸Sr (82.58%). Its standard atomic weight is 87.62(1).

Selenium (₃₄Se) has six natural isotopes that occur in significant quantities, along with the trace isotope ⁷⁹Se, which occurs in minute quantities in uranium ores. Five of these isotopes are stable: ⁷⁴Se, ⁷⁶Se, ⁷⁷Se, ⁷⁸Se, and ⁸⁰Se. The last three also occur as fission products, along with ⁷⁹Se, which has a half-life of 327,000 years, and ⁸²Se, which has a very long half-life (~10²⁰ years, decaying via double beta decay to ⁸²Kr) and for practical purposes can be considered to be stable. There are 23 other unstable isotopes that have been characterized, the longest-lived being ⁷⁹Se with a half-life 327,000 years, ⁷⁵Se with a half-life of 120 days, and ⁷²Se with a half-life of 8.40 days. Of the other isotopes, ⁷³Se has the longest half-life, 7.15 hours; most others have half-lives not exceeding 38 seconds.

Natural gallium (₃₁Ga) consists of a mixture of two stable isotopes: gallium-69 and gallium-71. Twenty-nine radioisotopes are known, all synthetic, with atomic masses ranging from 56 to 86; along with three nuclear isomers, ^64mGa, ^72mGa and ^74mGa. Most of the isotopes with atomic mass numbers below 69 decay to isotopes of zinc, while most of the isotopes with masses above 71 decay to isotopes of germanium. Among them, the most commercially important radioisotopes are gallium-67 and gallium-68.

Naturally occurring manganese (₂₅Mn) is composed of one stable isotope, ⁵⁵Mn. 26 radioisotopes have been characterized, with the most stable being ⁵³Mn with a half-life of 3.7 million years, ⁵⁴Mn with a half-life of 312.3 days, and ⁵²Mn with a half-life of 5.591 days. All of the remaining radioactive isotopes have half-lives that are less than 3 hours and the majority of these have half-lives that are less than a minute. This element also has 3 meta states.

Naturally occurring chromium (₂₄Cr) is composed of four stable isotopes; ⁵⁰Cr, ⁵²Cr, ⁵³Cr, and ⁵⁴Cr with ⁵²Cr being the most abundant (83.789% natural abundance). ⁵⁰Cr is suspected of decaying by β⁺β⁺ to ⁵⁰Ti with a half-life of (more than) 1.8×10¹⁷ years. Twenty-two radioisotopes, all of which are entirely synthetic, have been characterized, the most stable being ⁵¹Cr with a half-life of 27.7 days. All of the remaining radioactive isotopes have half-lives that are less than 24 hours and the majority of these have half-lives that are less than 1 minute. This element also has two meta states, ^45mCr, the more stable one, and ^59mCr, the least stable isotope or isomer.

Naturally occurring scandium (₂₁Sc) is composed of one stable isotope, ⁴⁵Sc. Twenty-five radioisotopes have been characterized, with the most stable being ⁴⁶Sc with a half-life of 83.8 days, ⁴⁷Sc with a half-life of 3.35 days, and ⁴⁸Sc with a half-life of 43.7 hours and ⁴⁴Sc with a half-life of 3.97 hours. All the remaining isotopes have half-lives that are less than four hours, and the majority of these have half-lives that are less than two minutes, the least stable being proton unbound ³⁹Sc with a half-life shorter than 300 nanoseconds. This element also has 13 meta states with the most stable being ^44m2Sc.

Einsteinium (₉₉Es) is a synthetic element, and thus a standard atomic weight cannot be given. Like all synthetic elements, it has no stable isotopes. The first isotope to be discovered was ²⁵³Es in 1952. There are 18 known radioisotopes from ²⁴⁰Es to ²⁵⁷Es, and 5 nuclear isomers. The longest-lived isotope is ²⁵²Es with a half-life of 471.7 days, or around 1.293 years.

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.
↑ Meshik, A.P.; Hohenberg, C.M.; Pravdivtseva, O.V.; Kapusta, Y.S. (2001). "Weak decay of ¹³⁰Ba and ¹³²Ba: Geochemical measurements". Physical Review C. 64 (3): 035205–1–035205–6. Bibcode:2001PhRvC..64c5205M. doi:10.1103/PhysRevC.64.035205.
↑ Wang, Meng; Huang, W.J.; Kondev, F.G.; Audi, G.; Naimi, S. (2021). "The AME 2020 atomic mass evaluation (II). Tables, graphs and references*". Chinese Physics C. 45 (3): 030003. doi:10.1088/1674-1137/abddaf.

Isotope masses from:
- Audi, Georges; Bersillon, Olivier; Blachot, Jean; Wapstra, Aaldert Hendrik (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:
- de Laeter, John Robert; Böhlke, John Karl; De Bièvre, Paul; Hidaka, Hiroshi; Peiser, H. Steffen; Rosman, Kevin J. R.; Taylor, Philip D. P. (2003). "Atomic weights of the elements. Review 2000 (IUPAC Technical Report)". Pure and Applied Chemistry . 75 (6): 683–800. doi: 10.1351/pac200375060683 .
- Wieser, Michael E. (2006). "Atomic weights of the elements 2005 (IUPAC Technical Report)". Pure and Applied Chemistry . 78 (11): 2051–2066. doi: 10.1351/pac200678112051 .

"News & Notices: Standard Atomic Weights Revised". International Union of Pure and Applied Chemistry. 19 October 2005.
Half-life, spin, and isomer data selected from the following sources.
- Audi, Georges; Bersillon, Olivier; Blachot, Jean; Wapstra, Aaldert Hendrik (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.x database". Brookhaven National Laboratory.
- Holden, Norman E. (2004). "11. Table of the Isotopes". In Lide, David R. (ed.). CRC Handbook of Chemistry and Physics (85th ed.). Boca Raton, Florida: CRC Press. ISBN 978-0-8493-0485-9.
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.

This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.

[5] Ba – Excited nuclear isomer.

[7] ( ) – Uncertainty (1σ) is given in concise form in parentheses after the corresponding last digits.

[TMS-8] # – Atomic mass marked #: value and uncertainty derived not from purely experimental data, but at least partly from trends from the Mass Surface (TMS).

[9] Modes of decay:
CD: Cluster decay
EC: Electron capture
IT: Isomeric transition
n: Neutron emission
p: Proton emission

[10] Bold italics symbol as daughter – Daughter product is nearly stable.

[11] Bold symbol as daughter – Daughter product is stable.

[12] ( ) spin value – Indicates spin with weak assignment arguments.

[TNN-13] # – Values marked # are not purely derived from experimental data, but at least partly from trends of neighboring nuclides (TNN).

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

[15] Primordial radioisotope

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

[FP-17] 1 2 3 4 5 6 7 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.

[Ba130-4] Meshik, A.P.; Hohenberg, C.M.; Pravdivtseva, O.V.; Kapusta, Y.S. (2001). "Weak decay of ¹³⁰Ba and ¹³²Ba: Geochemical measurements". Physical Review C. 64 (3): 035205–1–035205–6. Bibcode:2001PhRvC..64c5205M. doi:10.1103/PhysRevC.64.035205.

[AME2020_II-6] Wang, Meng; Huang, W.J.; Kondev, F.G.; Audi, G.; Naimi, S. (2021). "The AME 2020 atomic mass evaluation (II). Tables, graphs and references*". Chinese Physics C. 45 (3): 030003. doi:10.1088/1674-1137/abddaf.

[1]

[2]

[3]

[4]

[n 1]

[5]

[n 2]

[n 3]

[n 4]

[n 5]

[n 6]

[n 7]

[n 8]

[n 9]

[n 10]

[n 11]

[n 12]

CD:	Cluster decay
EC:	Electron capture
IT:	Isomeric transition
n:	Neutron emission
p:	Proton emission