Isotopes of strontium

Isotopes of strontium (₃₈Sr)
β+	83Rb
γ	–
γ	–
Standard atomic weight Ar°(Sr)
	87.62±0.01; 87.62±0.01 (abridged);
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Last updated July 28, 2023

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).

Only ⁸⁷Sr is radiogenic; it is produced by decay from the radioactive alkali metal ⁸⁷ Rb, which has a half-life of 4.88 × 10¹⁰ years (i.e. more than three times longer than the current age of the universe). Thus, there are two sources of ⁸⁷Sr in any material: primordial, formed during nucleosynthesis along with ⁸⁴Sr, ⁸⁶Sr and ⁸⁸Sr; and that formed by radioactive decay of ⁸⁷Rb. The ratio ⁸⁷Sr/⁸⁶Sr is the parameter typically reported in geologic investigations;^[4] ratios in minerals and rocks have values ranging from about 0.7 to greater than 4.0 (see rubidium–strontium dating). Because strontium has an electron configuration similar to that of calcium, it readily substitutes for calcium in minerals.

In addition to the four stable isotopes, thirty-two unstable isotopes of strontium are known to exist, ranging from ⁷³Sr to ¹⁰⁸Sr. Radioactive isotopes of strontium primarily decay into the neighbouring elements yttrium (⁸⁹Sr and heavier isotopes, via beta minus decay) and rubidium (⁸⁵Sr, ⁸³Sr and lighter isotopes, via positron emission or electron capture). The longest-lived of these isotopes, and the most relevantly studied, are ⁹⁰Sr with a half-life of 28.9 years, ⁸⁵Sr with a half-life of 64.853 days, and ⁸⁹Sr (⁸⁹Sr) with a half-life of 50.57 days. All other strontium isotopes have half-lives shorter than 50 days, most under 100 minutes.

Strontium-89 is an artificial radioisotope used in treatment of bone cancer;^[5] this application utilizes its chemical similarity to calcium, which allows it to substitute calcium in bone structures. In circumstances where cancer patients have widespread and painful bony metastases, the administration of ⁸⁹Sr results in the delivery of beta particles directly to the area of bony problem,^{[ further explanation needed ]} where calcium turnover is greatest. Strontium-90 is a by-product of nuclear fission, present in nuclear fallout. The 1986 Chernobyl nuclear accident contaminated a vast area with ⁹⁰Sr.^[6] It causes health problems, as it substitutes for calcium in bone, preventing expulsion from the body. Because it is a long-lived high-energy beta emitter, it is used in SNAP (Systems for Nuclear Auxiliary Power) devices. These devices hold promise for use in spacecraft, remote weather stations, navigational buoys, etc., where a lightweight, long-lived, nuclear-electric power source is required.

In 2020, researchers have found that mirror nuclides ⁷³Sr and ⁷³Br were found to not behave identically to each other as expected.^[7]

List of isotopes

Nuclide ^{[n 1]}	Z	N	Isotopic mass (Da) ^{[n 2]}^{[n 3]}	Half-life ^{[n 4]}	Decay mode ^{[n 5]}	Daughter isotope ^{[n 6]}^{[n 7]}	Spin and parity ^{[n 8]}^{[n 4]}	Natural abundance (mole fraction)
Nuclide ^{[n 1]}	Excitation energy			Half-life ^{[n 4]}	Decay mode ^{[n 5]}	Daughter isotope ^{[n 6]}^{[n 7]}	Spin and parity ^{[n 8]}^{[n 4]}	Normal proportion	Range of variation
⁷³Sr	38	35	72.96597(64)#	>25 ms	β⁺ (>99.9%)	⁷³Rb	1/2−#
⁷³Sr	38	35	72.96597(64)#	>25 ms	β⁺, p (<.1%)	⁷²Kr	1/2−#
⁷⁴Sr	38	36	73.95631(54)#	50# ms [>1.5 µs]	β⁺	⁷⁴Rb	0+
⁷⁵Sr	38	37	74.94995(24)	88(3) ms	β⁺ (93.5%)	⁷⁵Rb	(3/2−)
⁷⁵Sr	38	37	74.94995(24)	88(3) ms	β⁺, p (6.5%)	⁷⁴Kr	(3/2−)
⁷⁶Sr	38	38	75.94177(4)	7.89(7) s	β⁺	⁷⁶Rb	0+
⁷⁷Sr	38	39	76.937945(10)	9.0(2) s	β⁺ (99.75%)	⁷⁷Rb	5/2+
⁷⁷Sr	38	39	76.937945(10)	9.0(2) s	β⁺, p (.25%)	⁷⁶Kr	5/2+
⁷⁸Sr	38	40	77.932180(8)	159(8) s	β⁺	⁷⁸Rb	0+
⁷⁹Sr	38	41	78.929708(9)	2.25(10) min	β⁺	⁷⁹Rb	3/2(−)
⁸⁰Sr	38	42	79.924521(7)	106.3(15) min	β⁺	⁸⁰Rb	0+
⁸¹Sr	38	43	80.923212(7)	22.3(4) min	β⁺	⁸¹Rb	1/2−
⁸²Sr	38	44	81.918402(6)	25.36(3) d	EC	⁸²Rb	0+
⁸³Sr	38	45	82.917557(11)	32.41(3) h	β⁺	⁸³Rb	7/2+
^83mSr	259.15(9) keV			4.95(12) s	IT	⁸³Sr	1/2−
⁸⁴Sr	38	46	83.913425(3)	Observationally Stable ^{[n 9]}			0+	0.0056	0.0055–0.0058
⁸⁵Sr	38	47	84.912933(3)	64.853(8) d	EC	⁸⁵Rb	9/2+
^85mSr	238.66(6) keV			67.63(4) min	IT (86.6%)	⁸⁵Sr	1/2−
^85mSr	238.66(6) keV			67.63(4) min	β⁺ (13.4%)	⁸⁵Rb	1/2−
⁸⁶Sr	38	48	85.9092607309(91)	Stable			0+	0.0986	0.0975–0.0999
^86mSr	2955.68(21) keV			455(7) ns			8+
⁸⁷Sr^{[n 10]}	38	49	86.9088774970(91)	Stable			9/2+	0.0700	0.0694–0.0714
^87mSr	388.533(3) keV			2.815(12) h	IT (99.7%)	⁸⁷Sr	1/2−
^87mSr	388.533(3) keV			2.815(12) h	EC (.3%)	⁸⁷Rb	1/2−
⁸⁸Sr^{[n 11]}	38	50	87.9056122571(97)	Stable			0+	0.8258	0.8229–0.8275
⁸⁹Sr ^{[n 11]}	38	51	88.9074507(12)	50.57(3) d	β⁻	⁸⁹Y	5/2+
⁹⁰Sr ^{[n 11]}	38	52	89.907738(3)	28.90(3) y	β⁻	⁹⁰Y	0+
⁹¹Sr	38	53	90.910203(5)	9.63(5) h	β⁻	⁹¹Y	5/2+
⁹²Sr	38	54	91.911038(4)	2.66(4) h	β⁻	⁹²Y	0+
⁹³Sr	38	55	92.914026(8)	7.423(24) min	β⁻	⁹³Y	5/2+
⁹⁴Sr	38	56	93.915361(8)	75.3(2) s	β⁻	⁹⁴Y	0+
⁹⁵Sr	38	57	94.919359(8)	23.90(14) s	β⁻	⁹⁵Y	1/2+
⁹⁶Sr	38	58	95.921697(29)	1.07(1) s	β⁻	⁹⁶Y	0+
⁹⁷Sr	38	59	96.926153(21)	429(5) ms	β⁻ (99.95%)	⁹⁷Y	1/2+
⁹⁷Sr	38	59	96.926153(21)	429(5) ms	β⁻, n (.05%)	⁹⁶Y	1/2+
^97m1Sr	308.13(11) keV			170(10) ns			(7/2)+
^97m2Sr	830.8(2) keV			255(10) ns			(11/2−)#
⁹⁸Sr	38	60	97.928453(28)	0.653(2) s	β⁻ (99.75%)	⁹⁸Y	0+
⁹⁸Sr	38	60	97.928453(28)	0.653(2) s	β⁻, n (.25%)	⁹⁷Y	0+
⁹⁹Sr	38	61	98.93324(9)	0.269(1) s	β⁻ (99.9%)	⁹⁹Y	3/2+
⁹⁹Sr	38	61	98.93324(9)	0.269(1) s	β⁻, n (.1%)	⁹⁸Y	3/2+
¹⁰⁰Sr	38	62	99.93535(14)	202(3) ms	β⁻ (99.02%)	¹⁰⁰Y	0+
¹⁰⁰Sr	38	62	99.93535(14)	202(3) ms	β⁻, n (.98%)	⁹⁹Y	0+
¹⁰¹Sr	38	63	100.94052(13)	118(3) ms	β⁻ (97.63%)	¹⁰¹Y	(5/2−)
¹⁰¹Sr	38	63	100.94052(13)	118(3) ms	β⁻, n (2.37%)	¹⁰⁰Y	(5/2−)
¹⁰²Sr	38	64	101.94302(12)	69(6) ms	β⁻ (94.5%)	¹⁰²Y	0+
¹⁰²Sr	38	64	101.94302(12)	69(6) ms	β⁻, n (5.5%)	¹⁰¹Y	0+
¹⁰³Sr	38	65	102.94895(54)#	50# ms [>300 ns]	β⁻	¹⁰³Y
¹⁰⁴Sr	38	66	103.95233(75)#	30# ms [>300 ns]	β⁻	¹⁰⁴Y	0+
¹⁰⁵Sr	38	67	104.95858(75)#	20# ms [>300 ns]
¹⁰⁶Sr^[8]	38	68
¹⁰⁷Sr^[8]	38	69
¹⁰⁸Sr^[9]	38	70
This table header & footer: view

↑ ^mSr – 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).
1 2 # – Values marked # are not purely derived from experimental data, but at least partly from trends of neighboring nuclides (TNN).
↑ Modes of 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.
↑ Believed to decay by β⁺β⁺ to ⁸⁴Kr
↑ Used in rubidium–strontium dating
1 2 3 Fission product

Related Research Articles

Strontium-89 is a radioactive isotope of strontium produced by nuclear fission, with a half-life of 50.57 days. It undergoes β⁻ decay into yttrium-89. Strontium-89 has an application in medicine.

Francium (₈₇Fr) has no stable isotopes. A standard atomic weight cannot be given. Its most stable isotope is ²²³Fr with a half-life of 22 minutes, occurring in trace quantities in nature as an intermediate decay product of ²³⁵U.

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 gadolinium (₆₄Gd) is composed of 6 stable isotopes, ¹⁵⁴Gd, ¹⁵⁵Gd, ¹⁵⁶Gd, ¹⁵⁷Gd, ¹⁵⁸Gd and ¹⁶⁰Gd, and 1 radioisotope, ¹⁵²Gd, with ¹⁵⁸Gd being the most abundant (24.84% natural abundance). The predicted double beta decay of ¹⁶⁰Gd has never been observed; only a lower limit on its half-life of more than 1.3×10²¹ years has been set experimentally.

Promethium (₆₁Pm) is an artificial element, except in trace quantities as a product of spontaneous fission of ²³⁸U and ²³⁵U and alpha decay of ¹⁵¹Eu, and thus a standard atomic weight cannot be given. Like all artificial elements, it has no stable isotopes. It was first synthesized in 1945.

Naturally occurring praseodymium (₅₉Pr) is composed of one stable isotope, ¹⁴¹Pr. Thirty-eight radioisotopes have been characterized with the most stable being ¹⁴³Pr, with a half-life of 13.57 days and ¹⁴²Pr, with a half-life of 19.12 hours. All of the remaining radioactive isotopes have half-lives that are less than 5.985 hours and the majority of these have half-lives that are less than 33 seconds. This element also has 15 meta states with the most stable being ^138mPr, ^142mPr and ^134mPr.

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.

Antimony (₅₁Sb) occurs in two stable isotopes, ¹²¹Sb and ¹²³Sb. There are 35 artificial radioactive isotopes, the longest-lived of which are ¹²⁵Sb, with a half-life of 2.75856 years; ¹²⁴Sb, with a half-life of 60.2 days; and ¹²⁶Sb, with a half-life of 12.35 days. All other isotopes have half-lives less than 4 days, most less than an hour.

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.

Naturally occurring 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.

Naturally occurring rhodium (₄₅Rh) is composed of only one stable isotope, ¹⁰³Rh. The most stable radioisotopes are ¹⁰¹Rh with a half-life of 3.3 years, ¹⁰²Rh with a half-life of 207 days, and ⁹⁹Rh with a half-life of 16.1 days. Thirty other radioisotopes have been characterized with atomic weights ranging from 88.949 u (⁸⁹Rh) to 121.943 u (¹²²Rh). Most of these have half-lives that are less than an hour except ¹⁰⁰Rh and ¹⁰⁵Rh. There are also numerous meta states with the most stable being ^102mRh (0.141 MeV) with a half-life of about 3.7 years and ^101mRh (0.157 MeV) with a half-life of 4.34 days.

Naturally occurring zirconium (₄₀Zr) is composed of four stable isotopes (of which one may in the future be found radioactive), and one very long-lived radioisotope (⁹⁶Zr), a primordial nuclide that decays via double beta decay with an observed half-life of 2.0×10¹⁹ years; it can also undergo single beta decay, which is not yet observed, but the theoretically predicted value of t_1/2 is 2.4×10²⁰ years. The second most stable radioisotope is ⁹³Zr, which has a half-life of 1.53 million years. Thirty other radioisotopes have been observed. All have half-lives less than a day except for ⁹⁵Zr (64.02 days), ⁸⁸Zr (83.4 days), and ⁸⁹Zr (78.41 hours). The primary decay mode is electron capture for isotopes lighter than ⁹²Zr, and the primary mode for heavier isotopes is beta decay.

Natural yttrium (₃₉Y) is composed of a single isotope yttrium-89. The most stable radioisotopes are ⁸⁸Y, which has a half-life of 106.6 days and ⁹¹Y with a half-life of 58.51 days. All the other isotopes have half-lives of less than a day, except ⁸⁷Y, which has a half-life of 79.8 hours, and ⁹⁰Y, with 64 hours. The dominant decay mode below the stable ⁸⁹Y is electron capture and the dominant mode after it is beta emission. Thirty-five unstable isotopes have been characterized.

Rubidium (₃₇Rb) has 36 isotopes, with naturally occurring rubidium being composed of just two isotopes; ⁸⁵Rb (72.2%) and the radioactive ⁸⁷Rb (27.8%). Normal mixes of rubidium are radioactive enough to fog photographic film in approximately 30 to 60 days.

Bromine (₃₅Br) has two stable isotopes, ⁷⁹Br and ⁸¹Br, and 32 known radioisotopes, the most stable of which is ⁷⁷Br, with a half-life of 57.036 hours.

Germanium (₃₂Ge) has five naturally occurring isotopes, ⁷⁰Ge, ⁷²Ge, ⁷³Ge, ⁷⁴Ge, and ⁷⁶Ge. Of these, ⁷⁶Ge is very slightly radioactive, decaying by double beta decay with a half-life of 1.78 × 10²¹ years (130 billion times the age of the universe).

Naturally occurring zinc (₃₀Zn) is composed of the 5 stable isotopes ⁶⁴Zn, ⁶⁶Zn, ⁶⁷Zn, ⁶⁸Zn, and ⁷⁰Zn with ⁶⁴Zn being the most abundant. Twenty-five radioisotopes have been characterised with the most abundant and stable being ⁶⁵Zn with a half-life of 244.26 days, and ⁷²Zn with a half-life of 46.5 hours. All of the remaining radioactive isotopes have half-lives that are less than 14 hours and the majority of these have half-lives that are less than 1 second. This element also has 10 meta states.

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 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.

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: Strontium". CIAAW. 1969.
↑ Prohaska, Thomas; Irrgeher, Johanna; Benefield, Jacqueline; et al. (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.
↑ Dickin, Alan P. (2018). Radiogenic Isotope Geology (3 ed.). Cambridge: Cambridge University Press. ISBN 978-1-107-09944-9.
↑ Reddy, Eashwer K.; Robinson, Ralph G.; Mansfield, Carl M. (January 1986). "Strontium 89 for Palliation of Bone Metastases". Journal of the National Medical Association. 78 (1): 27–32. ISSN 0027-9684. PMC 2571189 . PMID 2419578.
↑ Wilken, R.D.; Diehl, R. (1987). "Strontium-90 in environmental samples from Northern Germany before and after the Chernobyl accident". Radiochimica Acta. 41 (4): 157–162. doi:10.1524/ract.1987.41.4.157. S2CID 99369165.
↑ "Discovery by UMass Lowell-led team challenges nuclear theory". Space Daily. Retrieved 2022-06-26.
1 2 Ohnishi, Tetsuya; Kubo, Toshiyuki; Kusaka, Kensuke; et al. (2010). "Identification of 45 New Neutron-Rich Isotopes Produced by In-Flight Fission of a ²³⁸U Beam at 345 MeV/nucleon". J. Phys. Soc. Jpn. Physical Society of Japan. 79 (7): 073201. arXiv: 1006.0305 . Bibcode:2010JPSJ...79g3201T. doi: 10.1143/JPSJ.79.073201 .
↑ Sumikama, T.; et al. (2021). "Observation of new neutron-rich isotopes in the vicinity of ¹¹⁰Zr". Physical Review C. 103 (1): 014614. Bibcode:2021PhRvC.103a4614S. doi:10.1103/PhysRevC.103.014614. hdl: 10261/260248 . S2CID 234019083.

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.

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[8] Sr – Excited nuclear isomer.

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

[TMS-10] # – Atomic mass marked #: value and uncertainty derived not from purely experimental data, but at least partly from trends from the Mass Surface (TMS).

[TNN-11] 1 2 # – Values marked # are not purely derived from experimental data, but at least partly from trends of neighboring nuclides (TNN).

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

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

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

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

[16] Believed to decay by β⁺β⁺ to ⁸⁴Kr

[17] Used in rubidium–strontium dating

[FP-18] 1 2 3 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: Strontium". CIAAW. 1969.

[CIAAW2021-3] Prohaska, Thomas; Irrgeher, Johanna; Benefield, Jacqueline; et al. (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.

[4] Dickin, Alan P. (2018). Radiogenic Isotope Geology (3 ed.). Cambridge: Cambridge University Press. ISBN 978-1-107-09944-9.

[5] Reddy, Eashwer K.; Robinson, Ralph G.; Mansfield, Carl M. (January 1986). "Strontium 89 for Palliation of Bone Metastases". Journal of the National Medical Association. 78 (1): 27–32. ISSN 0027-9684. PMC 2571189 . PMID 2419578.

[6] Wilken, R.D.; Diehl, R. (1987). "Strontium-90 in environmental samples from Northern Germany before and after the Chernobyl accident". Radiochimica Acta. 41 (4): 157–162. doi:10.1524/ract.1987.41.4.157. S2CID 99369165.

[7] "Discovery by UMass Lowell-led team challenges nuclear theory". Space Daily. Retrieved 2022-06-26.

[Ohnishi-19] 1 2 Ohnishi, Tetsuya; Kubo, Toshiyuki; Kusaka, Kensuke; et al. (2010). "Identification of 45 New Neutron-Rich Isotopes Produced by In-Flight Fission of a ²³⁸U Beam at 345 MeV/nucleon". J. Phys. Soc. Jpn. Physical Society of Japan. 79 (7): 073201. arXiv: 1006.0305 . Bibcode:2010JPSJ...79g3201T. doi: 10.1143/JPSJ.79.073201 .

[20] Sumikama, T.; et al. (2021). "Observation of new neutron-rich isotopes in the vicinity of ¹¹⁰Zr". Physical Review C. 103 (1): 014614. Bibcode:2021PhRvC.103a4614S. doi:10.1103/PhysRevC.103.014614. hdl: 10261/260248 . S2CID 234019083.

[1]

[2]

[3]

[4]

[5]

[6]

[7]

[n 1]

[n 2]

[n 3]

[n 4]

[n 5]

[n 6]

[n 7]

[n 8]

[n 9]

[n 10]

[n 11]

[8]

[9]

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