Isotopes of lead
Lead (Pb) has four stable isotopes: 204Pb, 206Pb, 207Pb, 208Pb. Lead-204 is entirely a primordial nuclide and is not a radiogenic nuclide. The three isotopes lead-206, lead-207, and lead-208 represent the ends of three decay chains: the uranium series (or radium series), the actinium series, and the thorium series, respectively. These series represent the decay chain products of long-lived primordial U-238, U-235, and Th-232, respectively. However, each of them also occurs, to some extent, as primordial isotopes that were made in supernovae, rather than radiogenically as daughter products. The fixed ratio of lead-204 to the primordial amounts of the other lead isotopes may be used as the baseline to estimate the extra amounts of radiogenic lead present in rocks as a result of decay from uranium and thorium. (See lead-lead dating and uranium-lead dating).
The longest-lived radioisotopes are 205Pb with a half-life of ~15.3 million years and 202Pb with a half-life of ~53,000 years. Of naturally-occurring radioisotopes, the shortest half-life is 22.20 years for 210Pb, which is useful for studying the sedimentation chronology of environmental samples on time scales shorter than 100 years.[1]
The relative atomic mass (abundance-weighted average of the stable isotopes) is 207.2(1). Lead is the element with the heaviest stable isotope, 208Pb. (The more massive 209Bi, long considered to be stable, actually has a half-life of 1.9×1019 years). A total of 38 Pb isotopes are now known, including very unstable synthetic species.
In its fully ionized state the isotope 205Pb also becomes stable.[2]
Lead-206
206Pb is the final step in the decay chain of 238U, the "radium series" or "uranium series". In a closed system, over time, a given mass of 238U will decay in a sequence of steps culminating in 206Pb. The production of intermediate products eventually reaches an equilibrium (though this takes a long time, as the half-life of 234U is 245,500 years.) Once this stabilized system is reached, the ratio of 238U to 206Pb will steadily decrease, while the ratios of the other intermediate products to each other remain constant.
Like most radioisotopes found in the radium series, 206Pb was initially named as a variation of radium, specifically radium G. It is the decay product of both 210Po (historically called radium F) by alpha decay, and the much more rare 206Tl (radium EII) by beta decay.
Lead 207, 208, and 204
207Pb is the end of the Actinium series from 235U.
208Pb is the end of the Thorium series from 232Th. It is notable for its unusually low neutron capture cross section (even lower than that of deuterium in the thermal spectrum), making it of interest for lead-cooled fast reactors. While it only makes up approximately half of the composition of lead in most places on Earth, it can be found naturally enriched up to around 90% in thorium ores.[3] It is notable as the heaviest known stable isotope of any element.
204Pb is entirely primordial, and is thus useful for estimating the fraction of the other lead isotopes in a given sample that are also primordial (since the relative fractions of the various primordial lead isotopes is constant everywhere). Any excess lead 206, 207, and 208 is thus assumed to be radiogenic in origin, allowing various uranium and thorium dating schemes to be used to estimate the age of rocks (time since their formation).
Table
nuclide symbol |
historic name |
Z(p) | N(n) | isotopic mass (u) |
half-life | decay mode(s)[4][n 1] |
daughter isotope(s)[n 2] |
nuclear spin |
representative isotopic composition (mole fraction) |
range of natural variation (mole fraction) |
---|---|---|---|---|---|---|---|---|---|---|
excitation energy | ||||||||||
178Pb | 82 | 96 | 178.003830(26) | 0.23(15) ms | 0+ | |||||
179Pb | 82 | 97 | 179.00215(21)# | 3# ms | 5/2−# | |||||
180Pb | 82 | 98 | 179.997918(22) | 4.5(11) ms | 0+ | |||||
181Pb | 82 | 99 | 180.99662(10) | 45(20) ms | α (98%) | 177Hg | 5/2−# | |||
β+ (2%) | 181Tl | |||||||||
182Pb | 82 | 100 | 181.992672(15) | 60(40) ms [55(+40−35) ms] |
α (98%) | 178Hg | 0+ | |||
β+ (2%) | 182Tl | |||||||||
183Pb | 82 | 101 | 182.99187(3) | 535(30) ms | α (94%) | 179Hg | (3/2−) | |||
β+ (6%) | 183Tl | |||||||||
183mPb | 94(8) keV | 415(20) ms | α | 179Hg | (13/2+) | |||||
β+ (rare) | 183Tl | |||||||||
184Pb | 82 | 102 | 183.988142(15) | 490(25) ms | α | 180Hg | 0+ | |||
β+ (rare) | 184Tl | |||||||||
185Pb | 82 | 103 | 184.987610(17) | 6.3(4) s | α | 181Hg | 3/2− | |||
β+ (rare) | 185Tl | |||||||||
185mPb | 60(40)# keV | 4.07(15) s | α | 181Hg | 13/2+ | |||||
β+ (rare) | 185Tl | |||||||||
186Pb | 82 | 104 | 185.984239(12) | 4.82(3) s | α (56%) | 182Hg | 0+ | |||
β+ (44%) | 186Tl | |||||||||
187Pb | 82 | 105 | 186.983918(9) | 15.2(3) s | β+ | 187Tl | (3/2−) | |||
α | 183Hg | |||||||||
187mPb | 11(11) keV | 18.3(3) s | β+ (98%) | 187Tl | (13/2+) | |||||
α (2%) | 183Hg | |||||||||
188Pb | 82 | 106 | 187.980874(11) | 25.5(1) s | β+ (91.5%) | 188Tl | 0+ | |||
α (8.5%) | 184Hg | |||||||||
188m1Pb | 2578.2(7) keV | 830(210) ns | (8−) | |||||||
188m2Pb | 2800(50) keV | 797(21) ns | ||||||||
189Pb | 82 | 107 | 188.98081(4) | 51(3) s | β+ | 189Tl | (3/2−) | |||
189mPb | 40(30)# keV | 1# min | β+ (99.6%) | 189Tl | (13/2+) | |||||
α (.4%) | 185Hg | |||||||||
190Pb | 82 | 108 | 189.978082(13) | 71(1) s | β+ (99.1%) | 190Tl | 0+ | |||
α (.9%) | 186Hg | |||||||||
190m1Pb | 2614.8(8) keV | 150 ns | (10)+ | |||||||
190m2Pb | 2618(20) keV | 25 µs | (12+) | |||||||
190m3Pb | 2658.2(8) keV | 7.2(6) µs | (11)− | |||||||
191Pb | 82 | 109 | 190.97827(4) | 1.33(8) min | β+ (99.987%) | 191Tl | (3/2−) | |||
α (.013%) | 187Hg | |||||||||
191mPb | 20(50) keV | 2.18(8) min | β+ (99.98%) | 191Tl | 13/2(+) | |||||
α (.02%) | 187Hg | |||||||||
192Pb | 82 | 110 | 191.975785(14) | 3.5(1) min | β+ (99.99%) | 192Tl | 0+ | |||
α (.0061%) | 188Hg | |||||||||
192m1Pb | 2581.1(1) keV | 164(7) ns | (10)+ | |||||||
192m2Pb | 2625.1(11) keV | 1.1(5) µs | (12+) | |||||||
192m3Pb | 2743.5(4) keV | 756(21) ns | (11)− | |||||||
193Pb | 82 | 111 | 192.97617(5) | 5# min | β+ | 193Tl | (3/2−) | |||
193m1Pb | 130(80)# keV | 5.8(2) min | β+ | 193Tl | 13/2(+) | |||||
193m2Pb | 2612.5(5)+X keV | 135(+25−15) ns | (33/2+) | |||||||
194Pb | 82 | 112 | 193.974012(19) | 12.0(5) min | β+ (100%) | 194Tl | 0+ | |||
α (7.3×10−6%) | 190Hg | |||||||||
195Pb | 82 | 113 | 194.974542(25) | ~15 min | β+ | 195Tl | 3/2#- | |||
195m1Pb | 202.9(7) keV | 15.0(12) min | β+ | 195Tl | 13/2+ | |||||
195m2Pb | 1759.0(7) keV | 10.0(7) µs | 21/2− | |||||||
196Pb | 82 | 114 | 195.972774(15) | 37(3) min | β+ | 196Tl | 0+ | |||
α (3×10−5%) | 192Hg | |||||||||
196m1Pb | 1049.20(9) keV | <100 ns | 2+ | |||||||
196m2Pb | 1738.27(12) keV | <1 µs | 4+ | |||||||
196m3Pb | 1797.51(14) keV | 140(14) ns | 5− | |||||||
196m4Pb | 2693.5(5) keV | 270(4) ns | (12+) | |||||||
197Pb | 82 | 115 | 196.973431(6) | 8.1(17) min | β+ | 197Tl | 3/2− | |||
197m1Pb | 319.31(11) keV | 42.9(9) min | β+ (81%) | 197Tl | 13/2+ | |||||
IT (19%) | 197Pb | |||||||||
α (3×10−4%) | 193Hg | |||||||||
197m2Pb | 1914.10(25) keV | 1.15(20) µs | 21/2− | |||||||
198Pb | 82 | 116 | 197.972034(16) | 2.4(1) h | β+ | 198Tl | 0+ | |||
198m1Pb | 2141.4(4) keV | 4.19(10) µs | (7)− | |||||||
198m2Pb | 2231.4(5) keV | 137(10) ns | (9)− | |||||||
198m3Pb | 2820.5(7) keV | 212(4) ns | (12)+ | |||||||
199Pb | 82 | 117 | 198.972917(28) | 90(10) min | β+ | 199Tl | 3/2− | |||
199m1Pb | 429.5(27) keV | 12.2(3) min | IT (93%) | 199Pb | (13/2+) | |||||
β+ (7%) | 199Tl | |||||||||
199m2Pb | 2563.8(27) keV | 10.1(2) µs | (29/2−) | |||||||
200Pb | 82 | 118 | 199.971827(12) | 21.5(4) h | β+ | 200Tl | 0+ | |||
201Pb | 82 | 119 | 200.972885(24) | 9.33(3) h | EC (99%) | 201Pb | 5/2− | |||
β+ (1%) | 201Tl | |||||||||
201m1Pb | 629.14(17) keV | 61(2) s | 13/2+ | |||||||
201m2Pb | 2718.5+X keV | 508(5) ns | (29/2−) | |||||||
202Pb | 82 | 120 | 201.972159(9) | 52.5(28)×103 y | EC (99%) | 202Tl | 0+ | |||
α (1%) | 198Hg | |||||||||
202m1Pb | 2169.83(7) keV | 3.53(1) h | IT (90.5%) | 202Pb | 9− | |||||
EC (9.5%) | 202Tl | |||||||||
202m2Pb | 4142.9(11) keV | 110(5) ns | (16+) | |||||||
202m3Pb | 5345.9(13) keV | 107(5) ns | (19−) | |||||||
203Pb | 82 | 121 | 202.973391(7) | 51.873(9) h | EC | 203Tl | 5/2− | |||
203m1Pb | 825.20(9) keV | 6.21(8) s | IT | 203Pb | 13/2+ | |||||
203m2Pb | 2949.47(22) keV | 480(7) ms | 29/2− | |||||||
203m3Pb | 2923.4+X keV | 122(4) ns | (25/2−) | |||||||
204Pb[n 3] | 82 | 122 | 203.9730436(13) | Observationally Stable[n 4] | 0+ | 0.014(1) | 0.0104–0.0165 | |||
204m1Pb | 1274.00(4) keV | 265(10) ns | 4+ | |||||||
204m2Pb | 2185.79(5) keV | 67.2(3) min | 9− | |||||||
204m3Pb | 2264.33(4) keV | 0.45(+10−3) µs | 7− | |||||||
205Pb | 82 | 123 | 204.9744818(13) | 15.3(7)×106 y | EC | 205Tl | 5/2− | |||
205m1Pb | 2.329(7) keV | 24.2(4) µs | 1/2− | |||||||
205m2Pb | 1013.839(13) keV | 5.55(2) ms | 13/2+ | |||||||
205m3Pb | 3195.7(5) keV | 217(5) ns | 25/2− | |||||||
206Pb[n 3][n 5] | Radium G | 82 | 124 | 205.9744653(13) | Observationally Stable[n 6] | 0+ | 0.241(1) | 0.2084–0.2748 | ||
206m1Pb | 2200.14(4) keV | 125(2) µs | 7− | |||||||
206m2Pb | 4027.3(7) keV | 202(3) ns | 12+ | |||||||
207Pb[n 3][n 7] | Actinium D | 82 | 125 | 206.9758969(13) | Observationally Stable[n 8] | 1/2− | 0.221(1) | 0.1762–0.2365 | ||
207mPb | 1633.368(5) keV | 806(6) ms | IT | 207Pb | 13/2+ | |||||
208Pb[n 9] | Thorium D | 82 | 126 | 207.9766521(13) | Observationally Stable[n 10] | 0+ | 0.524(1) | 0.5128–0.5621 | ||
208mPb | 4895(2) keV | 500(10) ns | 10+ | |||||||
209Pb | 82 | 127 | 208.9810901(19) | 3.253(14) h | β− | 209Bi | 9/2+ | Trace[n 11] | ||
210Pb | Radium D Radiolead Radio-lead |
82 | 128 | 209.9841885(16) | 22.20(22) y | β− (100%) | 210Bi | 0+ | Trace[n 12] | |
α (1.9×10−6%) | 206Hg | |||||||||
210mPb | 1278(5) keV | 201(17) ns | 8+ | |||||||
211Pb | Actinium B | 82 | 129 | 210.9887370(29) | 36.1(2) min | β− | 211Bi | 9/2+ | Trace[n 13] | |
212Pb | Thorium B | 82 | 130 | 211.9918975(24) | 10.64(1) h | β− | 212Bi | 0+ | Trace[n 14] | |
212mPb | 1335(10) keV | 5(1) µs | (8+) | |||||||
213Pb | 82 | 131 | 212.996581(8) | 10.2(3) min | β− | 213Bi | (9/2+) | |||
214Pb | Radium B | 82 | 132 | 213.9998054(26) | 26.8(9) min | β− | 214Bi | 0+ | Trace[n 12] | |
215Pb | 82 | 133 | 215.00481(44)# | 36(1) s | 5/2+# |
- ↑ Abbreviations:
EC: Electron capture
IT: Isomeric transition - ↑ Bold for stable isotopes, bold italics for nearly-stable isotopes (half-life longer than the age of the universe)
- 1 2 3 Used in lead-lead dating
- ↑ Believed to undergo α decay to 200Hg with a half-life over 140×1015 years
- ↑ Final decay product of 4n+2 decay chain (the Radium or Uranium series)
- ↑ Believed to undergo α decay to 202Hg
- ↑ Final decay product of 4n+3 decay chain (the Actinium series)
- ↑ Believed to undergo α decay to 203Hg
- ↑ Final decay product of 4n decay chain (the Thorium series)
- ↑ Heaviest observationally stable nuclide, believed to undergo α decay to 204Hg with a half-life over 2×1019 years
- ↑ Cluster decay product of 223Ra, which occurs in the decay chain of 235U
- 1 2 Intermediate decay product of 238U
- ↑ Intermediate decay product of 235U
- ↑ Intermediate decay product of 232Th
Notes
- Evaluated isotopic composition is for most but not all commercial samples.
- 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
- ↑ Determining the Ages of Recent Sediments Using Measurements of Trace Radioactivity H.W. Jeter, Terra et Aqua, 78, 21-28 (2000)
- ↑ Takahashi, K; Boyd, R. N.; Mathews, G. J.; Yokoi, K. (October 1987). "Bound-state beta decay of highly ionized atoms" (PDF). Physical Review C (New York, NY: American Institute of Physics for the American Physical Society) 36 (4). ISSN 0556-2813. OCLC 1639677. Retrieved 2013-08-27.
- ↑ A. Yu. Smirnov; V. D. Borisevich; A. Sulaberidze (July 2012). "Evaluation of specific cost of obtainment of lead-208 isotope by gas centrifuges using various raw materials". Theoretical Foundations of Chemical Engineering 46 (4): 373–378.
- ↑ "Universal Nuclide Chart". nucleonica. Retrieved 2013-08-28. (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.
Isotopes of thallium | Isotopes of lead | Isotopes of bismuth |
Table of nuclides |
Isotopes of the chemical elements | |||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
1 H |
2 He | ||||||||||||||||
3 Li |
4 Be |
5 B |
6 C |
7 N |
8 O |
9 F |
10 Ne | ||||||||||
11 Na |
12 Mg |
13 Al |
14 Si |
15 P |
16 S |
17 Cl |
18 Ar | ||||||||||
19 K |
20 Ca |
21 Sc |
22 Ti |
23 V |
24 Cr |
25 Mn |
26 Fe |
27 Co |
28 Ni |
29 Cu |
30 Zn |
31 Ga |
32 Ge |
33 As |
34 Se |
35 Br |
36 Kr |
37 Rb |
38 Sr |
39 Y |
40 Zr |
41 Nb |
42 Mo |
43 Tc |
44 Ru |
45 Rh |
46 Pd |
47 Ag |
48 Cd |
49 In |
50 Sn |
51 Sb |
52 Te |
53 I |
54 Xe |
55 Cs |
56 Ba |
72 Hf |
73 Ta |
74 W |
75 Re |
76 Os |
77 Ir |
78 Pt |
79 Au |
80 Hg |
81 Tl |
82 Pb |
83 Bi |
84 Po |
85 At |
86 Rn | |
87 Fr |
88 Ra |
104 Rf |
105 Db |
106 Sg |
107 Bh |
108 Hs |
109 Mt |
110 Ds |
111 Rg |
112 Cn |
113 Uut |
114 Fl |
115 Uup |
116 Lv |
117 Uus |
118 Uuo | |
57 La |
58 Ce |
59 Pr |
60 Nd |
61 Pm |
62 Sm |
63 Eu |
64 Gd |
65 Tb |
66 Dy |
67 Ho |
68 Er |
69 Tm |
70 Yb |
71 Lu | |||
89 Ac |
90 Th |
91 Pa |
92 U |
93 Np |
94 Pu |
95 Am |
96 Cm |
97 Bk |
98 Cf |
99 Es |
100 Fm |
101 Md |
102 No |
103 Lr | |||
|