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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). Standard atomic mass: 107.8682(2) u. Twenty-eight radioisotopes have been characterised 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 93.943 u (94Ag) to 123.929 u (124Ag). 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 Ag 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.
Standard atomic mass: 107.8682(2) u

Table

nuclide
symbol
Z(p) N(n)  
isotopic mass (u)
 
half-life 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] 0+#
94m1Ag 1350(400)# keV 422(16) ms (7+)
94m2Ag 6500(2000)# keV 300(200) ms (21+)
95Ag 47 48 94.93548(43)# 1.74(13) s (9/2+)
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 (8+)
96m1Ag 0(50)# keV 6.9(6) s (2+)
96m2Ag 700(200) ns
97Ag 47 50 96.92397(35) 25.3(3) s (9/2+)
97mAg 2343(49) keV 5 ns (21/2+)
98Ag 47 51 97.92157(7) 47.5(3) s (5+)
98mAg 167.83(15) keV 220(20) ns (3+)
99Ag 47 52 98.91760(16) 124(3) s (9/2)+
99mAg 506.1(4) keV 10.5(5) s (1/2-)
100Ag 47 53 99.91610(8) 2.01(9) min (5)+
100mAg 15.52(16) keV 2.24(13) min (2)+
101Ag 47 54 100.91280(11) 11.1(3) min 9/2+
101mAg 274.1(3) keV 3.10(10) s 1/2-
102Ag 47 55 101.91169(3) 12.9(3) min 5+
102mAg 9.3(4) keV 7.7(5) min 2+
103Ag 47 56 102.908973(18) 65.7(7) min 7/2+
103mAg 134.45(4) keV 5.7(3) s 1/2-
104Ag 47 57 103.908629(6) 69.2(10) min 5+
104mAg 6.9(4) keV 33.5(20) min 2+
105Ag 47 58 104.906529(12) 41.29(7) d 1/2-
105mAg 25.465(12) keV 7.23(16) min 7/2+
106Ag 47 59 105.906669(5) 23.96(4) min 1+
106mAg 89.66(7) keV 8.28(2) d 6+
107Ag 47 60 106.905097(5) STABLE 1/2- 0.51839(8)
107mAg 93.125(19) keV 44.3(2) s 7/2+
108Ag 47 61 107.905956(5) 2.37(1) min 1+
108mAg 109.440(7) keV 418(21) a 6+
109Ag 47 62 108.904752(3) STABLE 1/2- 0.48161(8)
109mAg 88.0341(11) keV 39.6(2) s 7/2+
110Ag 47 63 109.906107(3) 24.6(2) s 1+
110m1Ag 1.113 keV 660(40) ns 2-
110m2Ag 117.59(5) keV 249.950(24) d 6+
111Ag 47 64 110.905291(3) 7.45(1) d 1/2-
111mAg 59.82(4) keV 64.8(8) s 7/2+
112Ag 47 65 111.907005(18) 3.130(9) h 2(-)
113Ag 47 66 112.906567(18) 5.37(5) h 1/2-
113mAg 43.50(10) keV 68.7(16) s 7/2+
114Ag 47 67 113.908804(27) 4.6(1) s 1+
114mAg 199(5) keV 1.50(5) ms (<7+)
115Ag 47 68 114.90876(4) 20.0(5) min 1/2-
115mAg 41.16(10) keV 18.0(7) s 7/2+
116Ag 47 69 115.91136(5) 2.68(10) min (2)-
116mAg 81.90(20) keV 8.6(3) s (5+)
117Ag 47 70 116.91168(5) 73.6(14) s [72.8(+20-7) s] 1/2-#
117mAg 28.6(2) keV 5.34(5) s (7/2+)
118Ag 47 71 117.91458(7) 3.76(15) s 1-
118m1Ag 45.79(9) keV ~0.1 µs 0(-) to 2(-)
118m2Ag 127.49(5) keV 2.0(2) s 4(+)
118m3Ag 279.37(20) keV ~0.1 µs (2+,3+)
119Ag 47 72 118.91567(10) 6.0(5) s 1/2-#
119mAg 20(20)# keV 2.1(1) s 7/2+#
120Ag 47 73 119.91879(8) 1.23(4) s 3(+#)
120mAg 203.0(10) keV 371(24) ms 6(-)
121Ag 47 74 120.91985(16) 0.79(2) s (7/2+)#
122Ag 47 75 121.92353(22)# 0.529(13) s (3+)
122mAg 80(50)# keV 1.5(5) s 8-#
123Ag 47 76 122.92490(22)# 0.300(5) s (7/2+)
124Ag 47 77 123.92864(21)# 172(5) ms 3+#
124mAg 0(100)# keV 200# ms 8-#
125Ag 47 78 124.93043(32)# 166(7) ms (7/2+)#
126Ag 47 79 125.93450(32)# 107(12) ms 3+#
127Ag 47 80 126.93677(32)# 79(3) ms 7/2+#
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+

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

  • Isotope masses from Ame2003 Atomic Mass Evaluation by G. Audi, A.H. Wapstra, C. Thibault, J. Blachot and O. Bersillon in Nuclear Physics A729 (2003).
  • Isotopic compositions and standard atomic masses from Atomic weights of the elements. Review 2000 (IUPAC Technical Report). Pure Appl. Chem. Vol. 75, No. 6, pp. 683-800, (2003) and Atomic Weights Revised (2005).
  • Half-life, spin, and isomer data selected from these sources. Editing notes on this article's talk page.
    • Audi, Bersillon, Blachot, Wapstra. The Nubase2003 evaluation of nuclear and decay properties, Nuc. Phys. A 729, pp. 3-128 (2003).
    • National Nuclear Data Center, Brookhaven National Laboratory. Information extracted from the NuDat 2.1 database (retrieved Sept. 2005).
    • David R. Lide (ed.), Norman E. Holden in CRC Handbook of Chemistry and Physics, 85th Edition, online version. CRC Press. Boca Raton, Florida (2005). Section 11, Table of the Isotopes.


Isotopes of palladium Isotopes of silver Isotopes of cadmium
Index to isotope pages
 
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Isotopes_of_silver". A list of authors is available in Wikipedia.
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