Isotopes of silver

From Wikipedia, the free encyclopedia
  (Redirected from Silver-108)
Jump to: navigation, search

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 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.

Standard atomic mass: 107.8682(2) u

Table[edit]

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) a 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. ^ a b Theoretically capable of spontaneous fission
  5. ^ a b Fission product

Notes[edit]

  • 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[edit]

  1. ^ http://www.nucleonica.net/unc.aspx


Isotopes of palladium Isotopes of silver Isotopes of cadmium
Table of nuclides