Isotopes of tin

Tin (Sn) is the element with the greatest number of stable isotopes (ten), which is probably related to the fact that 50 is a "magic number" of protons. 29 additional unstable isotopes are known, including the "doubly magic" tin-100 (¹⁰⁰Sn) (discovered in 1994)^[1] and tin-132 (¹³²Sn). The longest-lived radioisotope is ¹²⁶Sn with a half-life of 230,000 years. All other radioisotopes have half-lives less than a year.

1 Tin-121m
2 Tin-126
3 Table
- 3.1 Notes
4 References

Tin-121m

Medium-lived
fission products
Prop: Unit:	t^½ a	Yield %	Q * keV	βγ *
¹⁵⁵Eu	4.76	.0803	252	βγ
⁸⁵Kr	10.76	.2180	687	βγ
^113mCd	14.1	.0008	316	β
⁹⁰Sr	28.9	4.505	2826	β
¹³⁷Cs	30.23	6.337	1176	βγ
^121mSn	43.9	.00005	390	βγ
¹⁵¹Sm	90	.5314	77	β

Tin-121m is a radioisotope and nuclear isomer of tin with a halflife of 43.9 years. In a normal thermal reactor, it has a very low fission product yield; thus, this isotope is not a significant contributor to nuclear waste.

Fast fission or fission of some heavier actinides will produce ^121mSn at higher yields.

Tin-126

Long-lived
fission products
Prop: Unit:	t^½ Ma	Yield %	Q * KeV	βγ *
⁹⁹Tc	0.211	6.1385	294	β
¹²⁶Sn	0.230	0.1084	4050	βγ
⁷⁹Se	0.327	0.0447	151	β
⁹³Zr	1.53	5.4575	91	βγ
¹³⁵Cs	2.3	6.9110	269	β
¹⁰⁷Pd	6.5	1.2499	33	β
¹²⁹I	15.7	0.8410	194	βγ

Chain yield, % per fission^[2]
	Thermal	Fast	14 MeV
²³²Th	not fissile	.0593±.0087	1.08 ± .17
²³³U	.233 ± .032	.325 ± .075	1.79 ± .24
²³⁵U	.0594±.0052	.098 ± .020	1.62 ± .49
²³⁸U	not fissile	.093 ± .020	1.38 ± .25
²³⁹Pu	.314 ± .049	.209 ± .044	?
²⁴¹Pu	.362 ± .089	.157 ± .031	?

Tin-126 is a radioisotope of tin and one of only 7 long-lived fission products. While tin-126's halflife of 230,000 years translates to a low specific activity that limits its radioactive hazard, its short-lived decay product, antimony-126, emits high-energy gamma radiation, making external exposure to tin-126 a potential concern.

¹²⁶Sn is in the middle of the mass range for fission products. Thermal reactors, which make up almost all current nuclear power plants, produce it at a very low yield (such as 0.0236% or 0.06%), since slow neutrons almost always fission ²³⁵U or ²³⁹Pu into unequal halves. Fast fission in a fast reactor or nuclear weapon, or fission of some heavy minor actinides like californium, will produce it at higher yields.

ANL factsheet

Actinides				Half-life	Fission products
²⁴⁴Cm	²⁴¹Pu ^f	²⁵⁰Cf	²⁴³Cm^f	10–30 y	¹³⁷Cs	⁹⁰Sr	⁸⁵Kr
²³²U ^f		²³⁸Pu	f is for fissile	69–90 y			¹⁵¹Sm nc➔
4n	²⁴⁹Cf ^f	²⁴²Am^f	f is for fissile	141–351	No fission product has half-life 10² to 2×10⁵ years
4n	²⁴¹Am		²⁵¹Cf ^f	431–898
²⁴⁰Pu	²²⁹Th	²⁴⁶Cm	²⁴³Am	5–7 ky
4n	²⁴⁵Cm^f	²⁵⁰Cm	²³⁹Pu ^f	8–24 ky
	²³³U ^f	²³⁰Th	²³¹Pa	32–160
	4n+1	²³⁴U	4n+3	211–290	⁹⁹Tc		¹²⁶Sn	⁷⁹Se
²⁴⁸Cm	4n+1	²⁴²Pu		340–373	Long-lived fission products
	²³⁷Np	4n+2		1–2 My	⁹³Zr	¹³⁵Cs nc➔
²³⁶U	4n+1		²⁴⁷Cm^f	6–23 My		¹⁰⁷Pd	¹²⁹I
²⁴⁴Pu				80 My	>7%	>5%	>1%	>.1%
²³²Th		²³⁸U	²³⁵U ^f	0.7–12 Gy	fission product yield

Table

nuclide symbol	Z(p)	N(n)	isotopic mass (u)	half-life	decay mode(s)^[3]^{[n 1]}	daughter isotope(s)^{[n 2]}	nuclear spin	representative isotopic composition (mole fraction)	range of natural variation (mole fraction)
nuclide symbol	excitation energy			half-life	decay mode(s)^[3]^{[n 1]}	daughter isotope(s)^{[n 2]}	nuclear spin	representative isotopic composition (mole fraction)	range of natural variation (mole fraction)
⁹⁹Sn^{[n 3]}	50	49	98.94933(64)#	5# ms			9/2+#
¹⁰⁰Sn^{[n 4]}	50	50	99.93904(76)	1.1(4) s [0.94(+54-27) s]	β⁺ (83%)	¹⁰⁰In	0+
¹⁰⁰Sn^{[n 4]}	50	50	99.93904(76)	1.1(4) s [0.94(+54-27) s]	β⁺, p (17%)	⁹⁹Cd	0+
¹⁰¹Sn	50	51	100.93606(32)#	3(1) s	β⁺	¹⁰¹In	5/2+#
¹⁰¹Sn	50	51	100.93606(32)#	3(1) s	β⁺, p (rare)	¹⁰⁰Cd	5/2+#
¹⁰²Sn	50	52	101.93030(14)	4.5(7) s	β⁺	¹⁰²In	0+
¹⁰²Sn	50	52	101.93030(14)	4.5(7) s	β⁺, p (rare)	¹⁰¹Cd	0+
^102mSn	2017(2) keV			720(220) ns			(6+)
¹⁰³Sn	50	53	102.92810(32)#	7.0(6) s	β⁺	¹⁰³In	5/2+#
¹⁰³Sn	50	53	102.92810(32)#	7.0(6) s	β⁺, p (rare)	¹⁰²Cd	5/2+#
¹⁰⁴Sn	50	54	103.92314(11)	20.8(5) s	β⁺	¹⁰⁴In	0+
¹⁰⁵Sn	50	55	104.92135(9)	34(1) s	β⁺	¹⁰⁵In	(5/2+)
¹⁰⁵Sn	50	55	104.92135(9)	34(1) s	β⁺, p (rare)	¹⁰⁵Cd	(5/2+)
¹⁰⁶Sn	50	56	105.91688(5)	115(5) s	β⁺	¹⁰⁶In	0+
¹⁰⁷Sn	50	57	106.91564(9)	2.90(5) min	β⁺	¹⁰⁷In	(5/2+)
¹⁰⁸Sn	50	58	107.911925(21)	10.30(8) min	β⁺	¹⁰⁸In	0+
¹⁰⁹Sn	50	59	108.911283(11)	18.0(2) min	β⁺	¹⁰⁹In	5/2(+)
¹¹⁰Sn	50	60	109.907843(15)	4.11(10) h	EC	¹¹⁰In	0+
¹¹¹Sn	50	61	110.907734(7)	35.3(6) min	β⁺	¹¹¹In	7/2+
^111mSn	254.72(8) keV			12.5(10) µs			1/2+
¹¹²Sn	50	62	111.904818(5)	Observationally Stable^{[n 5]}			0+	0.0097(1)
¹¹³Sn	50	63	112.905171(4)	115.09(3) d	β⁺	¹¹³In	1/2+
^113mSn	77.386(19) keV			21.4(4) min	IT (91.1%)	¹¹³Sn	7/2+
^113mSn	77.386(19) keV			21.4(4) min	β⁺ (8.9%)	¹¹³In	7/2+
¹¹⁴Sn	50	64	113.902779(3)	Observationally Stable^{[n 6]}			0+	0.0066(1)
^114mSn	3087.37(7) keV			733(14) ns			7-
¹¹⁵Sn	50	65	114.903342(3)	Observationally Stable^{[n 6]}			1/2+	0.0034(1)
^115m1Sn	612.81(4) keV			3.26(8) µs			7/2+
^115m2Sn	713.64(12) keV			159(1) µs			11/2-
¹¹⁶Sn	50	66	115.901741(3)	Observationally Stable^{[n 6]}			0+	0.1454(9)
¹¹⁷Sn	50	67	116.902952(3)	Observationally Stable^{[n 6]}			1/2+	0.0768(7)
^117m1Sn	314.58(4) keV			13.76(4) d	IT	¹¹⁷Sn	11/2-
^117m2Sn	2406.4(4) keV			1.75(7) µs			(19/2+)
¹¹⁸Sn	50	68	117.901603(3)	Observationally Stable^{[n 6]}			0+	0.2422(9)
¹¹⁹Sn	50	69	118.903308(3)	Observationally Stable^{[n 6]}			1/2+	0.0859(4)
^119m1Sn	89.531(13) keV			293.1(7) d	IT	¹¹⁹Sn	11/2-
^119m2Sn	2127.0(10) keV			9.6(12) µs			(19/2+)
¹²⁰Sn	50	70	119.9021947(27)	Observationally Stable^{[n 6]}			0+	0.3258(9)
^120m1Sn	2481.63(6) keV			11.8(5) µs			(7-)
^120m2Sn	2902.22(22) keV			6.26(11) µs			(10+)#
¹²¹Sn^{[n 7]}	50	71	120.9042355(27)	27.03(4) h	β^-	¹²¹Sb	3/2+
^121m1Sn	6.30(6) keV			43.9(5) a	IT (77.6%)	¹²¹Sn	11/2-
^121m1Sn	6.30(6) keV			43.9(5) a	β^- (22.4%)	¹²¹Sb	11/2-
^121m2Sn	1998.8(9) keV			5.3(5) µs			(19/2+)#
^121m3Sn	2834.6(18) keV			0.167(25) µs			(27/2-)
¹²²Sn^{[n 7]}	50	72	121.9034390(29)	Observationally Stable^{[n 8]}			0+	0.0463(3)
¹²³Sn^{[n 7]}	50	73	122.9057208(29)	129.2(4) d	β^-	¹²³Sb	11/2-
^123m1Sn	24.6(4) keV			40.06(1) min	β^-	¹²³Sb	3/2+
^123m2Sn	1945.0(10) keV			7.4(26) µs			(19/2+)
^123m3Sn	2153.0(12) keV			6 µs			(23/2+)
^123m4Sn	2713.0(14) keV			34 µs			(27/2-)
¹²⁴Sn^{[n 7]}	50	74	123.9052739(15)	Observationally Stable^{[n 9]}			0+	0.0579(5)
^124m1Sn	2204.622(23) keV			0.27(6) µs			5-
^124m2Sn	2325.01(4) keV			3.1(5) µs			7-
^124m3Sn	2656.6(5) keV			45(5) µs			(10+)#
¹²⁵Sn^{[n 7]}	50	75	124.9077841(16)	9.64(3) d	β^-	¹²⁵Sb	11/2-
^125mSn	27.50(14) keV			9.52(5) min			3/2+
¹²⁶Sn^{[n 10]}	50	76	125.907653(11)	2.30(14)×10⁵ a	β^- (66.5%)	^126m2Sb	0+
¹²⁶Sn^{[n 10]}	50	76	125.907653(11)	2.30(14)×10⁵ a	β^- (33.5%)	^126m1Sb	0+
^126m1Sn	2218.99(8) keV			6.6(14) µs			7-
^126m2Sn	2564.5(5) keV			7.7(5) µs			(10+)#
¹²⁷Sn	50	77	126.910360(26)	2.10(4) h	β^-	¹²⁷Sb	(11/2-)
^127mSn	4.7(3) keV			4.13(3) min	β^-	¹²⁷Sb	(3/2+)
¹²⁸Sn	50	78	127.910537(29)	59.07(14) min	β^-	¹²⁸Sb	0+
^128mSn	2091.50(11) keV			6.5(5) s	IT	¹²⁸Sn	(7-)
¹²⁹Sn	50	79	128.91348(3)	2.23(4) min	β^-	¹²⁹Sb	(3/2+)#
^129mSn	35.2(3) keV			6.9(1) min	β^- (99.99%)	¹²⁹Sb	(11/2-)#
^129mSn	35.2(3) keV			6.9(1) min	IT (.002%)	¹²⁹Sn	(11/2-)#
¹³⁰Sn	50	80	129.913967(11)	3.72(7) min	β^-	¹³⁰Sb	0+
^130m1Sn	1946.88(10) keV			1.7(1) min	β^-	¹³⁰Sb	(7-)#
^130m2Sn	2434.79(12) keV			1.61(15) µs			(10+)
¹³¹Sn	50	81	130.917000(23)	56.0(5) s	β^-	¹³¹Sb	(3/2+)
^131m1Sn	80(30)# keV			58.4(5) s	β^- (99.99%)	¹³¹Sb	(11/2-)
^131m1Sn	80(30)# keV			58.4(5) s	IT (.0004%)	¹³¹Sn	(11/2-)
^131m2Sn	4846.7(9) keV			300(20) ns			(19/2- to 23/2-)
¹³²Sn	50	82	131.917816(15)	39.7(8) s	β^-	¹³²Sb	0+
¹³³Sn	50	83	132.92383(4)	1.45(3) s	β^- (99.97%)	¹³³Sb	(7/2-)#
¹³³Sn	50	83	132.92383(4)	1.45(3) s	β^-, n (.0294%)	¹³²Sb	(7/2-)#
¹³⁴Sn	50	84	133.92829(11)	1.050(11) s	β^- (83%)	¹³⁴Sb	0+
¹³⁴Sn	50	84	133.92829(11)	1.050(11) s	β^-, n (17%)	¹³³Sb	0+
¹³⁵Sn	50	85	134.93473(43)#	530(20) ms	β^-	¹³⁵Sb	(7/2-)
¹³⁵Sn	50	85	134.93473(43)#	530(20) ms	β^-, n	¹³⁴Sb	(7/2-)
¹³⁶Sn	50	86	135.93934(54)#	0.25(3) s	β^-	¹³⁶Sb	0+
¹³⁶Sn	50	86	135.93934(54)#	0.25(3) s	β^-, n	¹³⁵Sb	0+
¹³⁷Sn	50	87	136.94599(64)#	190(60) ms	β^-	¹³⁷Sb	5/2-#

^ Abbreviations:
EC: Electron capture
IT: Isomeric transition
^ Bold for stable isotopes
^ Heaviest known nuclide with more protons than neutrons
^ Heaviest known nuclide with equal numbers of protons and neutrons
^ Believed to decay by β⁺β⁺ to ¹¹²Cd
^ ^a ^b ^c ^d ^e ^f ^g Theoretically capable of spontaneous fission
^ ^a ^b ^c ^d ^e Fission product
^ Believed to undergo β^-β^- decay to ¹²²Te
^ Believed to undergo β^-β^- decay to ¹²⁴Te with a half-life over 100×10¹⁵ years
^ Long-lived 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

^ Identification and decay spectroscopy of 100Sn at the GSI projectile fragment separator FRS, K. Sümmerer et al., Nucl. Phys. A616, 341 (1997).
^ http://www-nds.iaea.org/sgnucdat/c1.htm Chain Fission Yields, IAEA
^ http://www.nucleonica.net/unc.aspx

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. http://www.nndc.bnl.gov/amdc/nubase/Nubase2003.pdf.
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. http://www.iupac.org/publications/pac/75/6/0683/pdf/.
- 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. http://iupac.org/publications/pac/78/11/2051/pdf/. 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. http://www.nndc.bnl.gov/amdc/nubase/Nubase2003.pdf.
- National Nuclear Data Center. "NuDat 2.1 database". Brookhaven National Laboratory. http://www.nndc.bnl.gov/nudat2/. 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 978-0849304859.

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