Isotopes of silver

Naturally occurring silver (Ag) is composed of the two stable isotopes ¹⁰⁷Ag and ¹⁰⁹Ag with ¹⁰⁷Ag being the more abundant (51.839% natural abundance). Twenty-eight radioisotopes have been characterized with the most stable being ¹⁰⁵Ag with a half-life of 41.29 days, ¹¹¹Ag with a half-life of 7.45 days, and ¹¹²Ag with a half-life of 3.13 hours.

All of the remaining radioactive isotopes have half-lives that are less than an hour and the majority of these have half-lives that are less than 3 minutes. This element has numerous meta states with the most stable being ^108mAg (t_* 418 years), ^110mAg (t_* 249.79 days) and ^106mAg (t_* 8.28 days).

Isotopes of silver range in atomic weight from 92.950 u (⁹³Ag) to 129.950 u (¹³⁰Ag). The primary decay mode before the most abundant stable isotope, ¹⁰⁷Ag, is electron capture and the primary mode after is beta decay. The primary decay products before ¹⁰⁷Ag are palladium (element 46) isotopes and the primary products after are cadmium (element 48) isotopes.

The palladium isotope ¹⁰⁷Pd decays by beta emission to ¹⁰⁷Ag with a half-life of 6.5 million years. Iron meteorites are the only objects with a high enough palladium/silver ratio to yield measurable variations in ¹⁰⁷Ag abundance. Radiogenic ¹⁰⁷Ag was first discovered in the Santa Clara meteorite in 1978.

The discoverers suggest that the coalescence and differentiation of iron-cored small planets may have occurred 10 million years after a nucleosynthetic event. ¹⁰⁷Pd versus ¹⁰⁷Ag correlations observed in bodies, which have clearly been melted since the accretion of the solar system, must reflect the presence of live short-lived nuclides in the early solar system.

Relative atomic mass: 107.8682(2)

Table

nuclide symbol	Z(p)	N(n)	isotopic mass (u)	half-life	decay mode(s)[1][n 1]	daughter isotope(s)[n 2]	nuclear spin	representative isotopic composition (mole fraction)	range of natural variation (mole fraction)
	excitation energy
^93Ag	47	46	92.94978(64)#	5# ms [>1.5 µs]			9/2+#
^94Ag	47	47	93.94278(54)#	37(18) ms [26(+26−9) ms]	β^+	^94Pd	0+#
^94m1Ag	1350(400)# keV			422(16) ms	β^+ (>99.9%)	^94Pd	(7+)
					β^+, p (<.1%)	^93Rh
^94m2Ag	6500(2000)# keV			300(200) ms			(21+)
^95Ag	47	48	94.93548(43)#	1.74(13) s	β^+ (>99.9%)	^95Pd	(9/2+)
					β^+, p (<.1%)	^94Rh
^95m1Ag	344.2(3) keV			<0.5 s			(1/2−)
^95m2Ag	2531(1) keV			<16 ms			(23/2+)
^95m3Ag	4859(1) keV			<40 ms			(37/2+)
^96Ag	47	49	95.93068(43)#	4.45(4) s	β^+ (96.3%)	^96Pd	(8+)
					β^+, p (3.7%)	^95Rh
^96m1Ag	0(50)# keV			6.9(6) s			(2+)
^96m2Ag				700(200) ns
^97Ag	47	50	96.92397(35)	25.3(3) s	β^+	^97Pd	(9/2+)
^97mAg	2343(49) keV			5 ns			(21/2+)
^98Ag	47	51	97.92157(7)	47.5(3) s	β^+ (99.99%)	^98Pd	(5+)
					β^+, p (.0012%)	^97Rh
^98mAg	167.83(15) keV			220(20) ns			(3+)
^99Ag	47	52	98.91760(16)	124(3) s	β^+	^99Pd	(9/2)+
^99mAg	506.1(4) keV			10.5(5) s	IT	^99Ag	(1/2−)
^100Ag	47	53	99.91610(8)	2.01(9) min	β^+	^100Pd	(5)+
^100mAg	15.52(16) keV			2.24(13) min	IT	^100Ag	(2)+
					β^+	^100Pd
^101Ag	47	54	100.91280(11)	11.1(3) min	β^+	^101Pd	9/2+
^101mAg	274.1(3) keV			3.10(10) s	IT	^101Ag	1/2−
^102Ag	47	55	101.91169(3)	12.9(3) min	β^+	^102Pd	5+
^102mAg	9.3(4) keV			7.7(5) min	β^+ (51%)	^102Pd	2+
					IT (49%)	^102Ag
^103Ag	47	56	102.908973(18)	65.7(7) min	β^+	^103Pd	7/2+
^103mAg	134.45(4) keV			5.7(3) s	IT	^103Ag	1/2−
^104Ag	47	57	103.908629(6)	69.2(10) min	β^+	^104Pd	5+
^104mAg	6.9(4) keV			33.5(20) min	β^+ (99.93%)	^104Pd	2+
					IT (.07%)	^104Ag
^105Ag	47	58	104.906529(12)	41.29(7) d	β^+	^105Pd	1/2−
^105mAg	25.465(12) keV			7.23(16) min	IT (99.66%)	^105Ag	7/2+
					β^+ (.34%)	^105Pd
^106Ag	47	59	105.906669(5)	23.96(4) min	β^+ (99.5%)	^106Pd	1+
					β^− (0.5%)	^106Cd
^106mAg	89.66(7) keV			8.28(2) d	β^+	^106Pd	6+
					IT (4.16×10^−6%)	^106Ag
^107Ag[n 3]	47	60	106.905097(5)	Stable[n 4]			1/2−	0.51839(8)
^107mAg	93.125(19) keV			44.3(2) s	IT	^107Ag	7/2+
^108Ag	47	61	107.905956(5)	2.37(1) min	β^− (97.15%)	^108Cd	1+
					β^+ (2.85%)	^108Pd
^108mAg	109.440(7) keV			418(21) y	β^+ (91.3%)	^108Pd	6+
					IT (8.96%)	^108Ag
^109Ag[n 5]	47	62	108.904752(3)	Stable[n 4]			1/2−	0.48161(8)
^109mAg	88.0341(11) keV			39.6(2) s	IT	^109Ag	7/2+
^110Ag	47	63	109.906107(3)	24.6(2) s	β^− (99.7%)	^110Cd	1+
					EC (.3%)	^110Pd
^110m1Ag	1.113 keV			660(40) ns			2−
^110m2Ag	117.59(5) keV			249.950(24) d	β^− (98.64%)	^110Cd	6+
					IT (1.36%)	^110Ag
^111Ag[n 5]	47	64	110.905291(3)	7.45(1) d	β^−	^111Cd	1/2−
^111mAg	59.82(4) keV			64.8(8) s	IT (99.3%)	^111Ag	7/2+
					β^− (.7%)	^111Cd
^112Ag	47	65	111.907005(18)	3.130(9) h	β^−	^112Cd	2(−)
^113Ag	47	66	112.906567(18)	5.37(5) h	β^−	^113mCd	1/2−
^113mAg	43.50(10) keV			68.7(16) s	IT (64%)	^113Ag	7/2+
					β^− (36%)	^113Cd
^114Ag	47	67	113.908804(27)	4.6(1) s	β^−	^114Cd	1+
^114mAg	199(5) keV			1.50(5) ms	IT	^114Ag	(<7+)
^115Ag	47	68	114.90876(4)	20.0(5) min	β^−	^115mCd	1/2−
^115mAg	41.16(10) keV			18.0(7) s	β^− (79%)	^115Cd	7/2+
					IT (21%)	^115Ag
^116Ag	47	69	115.91136(5)	2.68(10) min	β^−	^116Cd	(2)−
^116mAg	81.90(20) keV			8.6(3) s	β^− (94%)	^116Cd	(5+)
					IT (6%)	^116Ag
^117Ag	47	70	116.91168(5)	73.6(14) s [72.8(+20−7) s]	β^−	^117mCd	1/2−#
^117mAg	28.6(2) keV			5.34(5) s	β^− (94%)	^117mCd	(7/2+)
					IT (6%)	^117Ag
^118Ag	47	71	117.91458(7)	3.76(15) s	β^−	^118Cd	1-
^118m1Ag	45.79(9) keV			~0.1 µs			0(−) to 2(−)
^118m2Ag	127.49(5) keV			2.0(2) s	β^− (59%)	^118Cd	4(+)
					IT (41%)	^118Ag
^118m3Ag	279.37(20) keV			~0.1 µs			(2+,3+)
^119Ag	47	72	118.91567(10)	6.0(5) s	β^−	^119mCd	1/2−#
^119mAg	20(20)# keV			2.1(1) s	β^−	^119Cd	7/2+#
^120Ag	47	73	119.91879(8)	1.23(4) s	β^− (99.99%)	^120Cd	3(+#)
					β^−, n (.003%)	^119Cd
^120mAg	203.0(10) keV			371(24) ms	β^− (63%)	^120Cd	6(−)
					IT (37%)	^120Ag
^121Ag	47	74	120.91985(16)	0.79(2) s	β^− (99.92%)	^121Cd	(7/2+)#
					β^−, n (.076%)	^120Cd
^122Ag	47	75	121.92353(22)#	0.529(13) s	β^− (>99.9%)	^122Cd	(3+)
					β^−, n (<.1%)	^121Cd
^122mAg	80(50)# keV			1.5(5) s	β^− (>99.9%)	^122Cd	8-#
					β^−, n (<.1%)	^121Cd
^123Ag	47	76	122.92490(22)#	0.300(5) s	β^− (99.45%)	^123Cd	(7/2+)
					β^−, n (.549%)	^122Cd
^124Ag	47	77	123.92864(21)#	172(5) ms	β^− (99.9%)	^124Cd	3+#
					β^−, n (.1%)	^123Cd
^124mAg	0(100)# keV			200# ms	β^−	^124Cd	8-#
					IT	^124Ag
^125Ag	47	78	124.93043(32)#	166(7) ms	β^− (>99.9%)	^125Cd	(7/2+)#
					β^−, n (<.1%)	^124Cd
^126Ag	47	79	125.93450(32)#	107(12) ms	β^− (>99.9%)	^126Cd	3+#
					β^−, n (<.1%)	^125Cd
^127Ag	47	80	126.93677(32)#	79(3) ms	β^− (>99.9%)	^127Cd	7/2+#
					β^−, n (<.1%)	^126Cd
^128Ag	47	81	127.94117(32)#	58(5) ms
^129Ag	47	82	128.94369(43)#	44(7) ms [46(+5−9) ms]			7/2+#
^129mAg	0(200)# keV			~160 ms			1/2−#
^130Ag	47	83	129.95045(36)#	~50 ms			0+

1. Abbreviations:
   EC: Electron capture
   IT: Isomeric transition
2. Bold for stable isotopes, bold italics for nearly-stable isotopes (half-life longer than the age of the universe)
3. Used to date certain events in the early history of the Solar System
4. Theoretically capable of spontaneous fission
5. Fission product

Notes

• The precision of the isotope abundances and atomic mass is limited through variations. The given ranges should be applicable to any normal terrestrial material.
• 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

1. "Universal Nuclide Chart". nucleonica. (registration required (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.
• 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. 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; 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.
  • 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.