Isotopes of lead

Lead (₈₂Pb) has four observationally 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; a fourth decay chain, the neptunium series, terminates with the thallium isotope ²⁰⁵Tl. The three series terminating in lead represent the decay chain products of long-lived primordial ²³⁸U, ²³⁵U, and ²³²Th. Each isotope 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. This is the basis for lead–lead dating and uranium–lead dating.

The longest-lived radioisotopes, both decaying by electron capture, are ²⁰⁵Pb with a half-life of 17.0 million years and ²⁰²Pb with a half-life of 52,500 years. A shorter-lived naturally occurring radioisotope, ²¹⁰Pb with a half-life of 22.2 years, is useful for studying the sedimentation chronology of environmental samples on time scales shorter than 100 years.

The heaviest stable isotope, ²⁰⁸Pb, belongs to this element. (The more massive ²⁰⁹Bi, long considered to be stable, actually has a half-life of 2.01×10¹⁹ years.) ²⁰⁸Pb is also a doubly magic isotope, as it has 82 protons and 126 neutrons. It is the heaviest doubly magic nuclide known.

The four primordial isotopes of lead are all observationally stable, meaning that they are predicted to undergo radioactive decay but no decay has been observed yet. These four isotopes are predicted to undergo alpha decay and become isotopes of mercury which are themselves radioactive or observationally stable.

There are trace quantities existing of the radioactive isotopes 209–214. The largest and most important is lead-210 as it has by far the longest half-life (22.2 years) and occurs in the abundant uranium decay series. Lead-211, -212, and -214 are present in the decay chains of uranium-235, thorium-232, and uranium-238, further, making these three lead isotopes also detectable in natural sources. The more minute traces of lead-209 arise from three rare decay branches: the beta-delayed-neutron decay of thallium-210 (in the uranium series), the last step of the neptunium series, traces of which are produced by neutron capture in uranium ores, and the very rare cluster decay of radium-223 (yielding also carbon-14). Lead-213 also occurs in a minor branch of the neptunium series. Lead-210 is particularly useful for helping to identify the ages of samples by measuring its ratio to lead-206 (both isotopes are present in a single decay chain).

In total, 43 lead isotopes have been synthesized, from ¹⁷⁸Pb to ²²⁰Pb.

List of isotopes

|-id=Lead-178 | rowspan=2|¹⁷⁸Pb | rowspan=2| | rowspan=2 style="text-align:right" | 82 | rowspan=2 style="text-align:right" | 96 | rowspan=2|178.003836(25) | rowspan=2|250(80)&nbsp;μs | α | ¹⁷⁴Hg | rowspan=2|0+ | rowspan=2| | rowspan=2| |- | β⁺? | ¹⁷⁸Tl |-id=Lead-179 | ¹⁷⁹Pb | | style="text-align:right" | 82 | style="text-align:right" | 97 | 179.002(87) | 2.7(2)&nbsp;ms | α | ¹⁷⁵Hg | (9/2−) | | |-id=Lead-180 | ¹⁸⁰Pb | | style="text-align:right" | 82 | style="text-align:right" | 98 | 179.997916(13) | 4.1(3)&nbsp;ms | α | ¹⁷⁶Hg | 0+ | | |-id=Lead-181 | rowspan=2|¹⁸¹Pb | rowspan=2| | rowspan=2 style="text-align:right" | 82 | rowspan=2 style="text-align:right" | 99 | rowspan=2|180.996661(91) | rowspan=2|39.0(8)&nbsp;ms | α | ¹⁷⁷Hg | rowspan=2|(9/2−) | rowspan=2| | rowspan=2| |- | β⁺? | ¹⁸¹Tl |-id=Lead-182 | rowspan=2|¹⁸²Pb | rowspan=2| | rowspan=2 style="text-align:right" | 82 | rowspan=2 style="text-align:right" | 100 | rowspan=2|181.992674(13) | rowspan=2|55(5)&nbsp;ms | α | ¹⁷⁸Hg | rowspan=2|0+ | rowspan=2| | rowspan=2| |- | β⁺? | ¹⁸²Tl |-id=Lead-183 | rowspan=2|¹⁸³Pb | rowspan=2| | rowspan=2 style="text-align:right" | 82 | rowspan=2 style="text-align:right" | 101 | rowspan=2|182.991863(31) | rowspan=2|535(30)&nbsp;ms | α | ¹⁷⁹Hg | rowspan=2|3/2− | rowspan=2| | rowspan=2| |- | β⁺? | ¹⁸³Tl |-id=Lead-183m | rowspan=3 style="text-indent:1em" | ^183mPb | rowspan=3| | rowspan=3 colspan="3" style="text-indent:2em" | 94(8)&nbsp;keV | rowspan=3|415(20)&nbsp;ms | α | ¹⁷⁹Hg | rowspan=3|13/2+ | rowspan=3| | rowspan=3| |- | β⁺? | ¹⁸³Tl |- | IT? | ¹⁸³Pb |-id=Lead-184 | rowspan=2|¹⁸⁴Pb | rowspan=2| | rowspan=2 style="text-align:right" | 82 | rowspan=2 style="text-align:right" | 102 | rowspan=2|183.988136(14) | rowspan=2|490(25)&nbsp;ms | α (80%) | ¹⁸⁰Hg | rowspan=2|0+ | rowspan=2| | rowspan=2| |- | β⁺? (20%) | ¹⁸⁴Tl |-id=Lead-185 | rowspan=2|¹⁸⁵Pb | rowspan=2| | rowspan=2 style="text-align:right" | 82 | rowspan=2 style="text-align:right" | 103 | rowspan=2|184.987610(17) | rowspan=2|6.3(4)&nbsp;s | β⁺ (66%) | ¹⁸⁵Tl | rowspan=2|3/2− | rowspan=2| | rowspan=2| |- | α (34%) | ¹⁸¹Hg |-id=Lead-185m | rowspan=2 style="text-indent:1em" | ^185mPb | rowspan=2| | rowspan=2 colspan="3" style="text-indent:2em" | 70(50)&nbsp;keV | rowspan=2|4.07(15)&nbsp;s | α (50%) | ¹⁸¹Hg | rowspan=2|13/2+ | rowspan=2| | rowspan=2| |- | β⁺? (50%) | ¹⁸⁵Tl |-id=Lead-186 | rowspan=2|¹⁸⁶Pb | rowspan=2| | rowspan=2 style="text-align:right" | 82 | rowspan=2 style="text-align:right" | 104 | rowspan=2|185.984239(12) | rowspan=2|4.82(3)&nbsp;s | β⁺? (60%) | ¹⁸⁶Tl | rowspan=2|0+ | rowspan=2| | rowspan=2| |- | α (40%) | ¹⁸²Hg |-id=Lead-187 | rowspan=2|¹⁸⁷Pb | rowspan=2| | rowspan=2 style="text-align:right" | 82 | rowspan=2 style="text-align:right" | 105 | rowspan=2|186.9839108(55) | rowspan=2|15.2(3)&nbsp;s | β⁺ (90.5%) | ¹⁸⁷Tl | rowspan=2|3/2− | rowspan=2| | rowspan=2| |- | α (9.5%) | ¹⁸³Hg |-id=Lead-187m | rowspan=2 style="text-indent:1em" | ^187mPb | rowspan=2| | rowspan=2 colspan="3" style="text-indent:2em" | 19(10)&nbsp;keV | rowspan=2|18.3(3)&nbsp;s | β⁺ (88%) | ¹⁸⁷Tl | rowspan=2|13/2+ | rowspan=2| | rowspan=2| |- | α (12%) | ¹⁸³Hg |-id=Lead-188 | rowspan=2|¹⁸⁸Pb | rowspan=2| | rowspan=2 style="text-align:right" | 82 | rowspan=2 style="text-align:right" | 106 | rowspan=2|187.980879(11) | rowspan=2|25.1(1)&nbsp;s | β⁺ (91.5%) | ¹⁸⁸Tl | rowspan=2|0+ | rowspan=2| | rowspan=2| |- | α (8.5%) | ¹⁸⁴Hg |-id=Lead-188m1 | style="text-indent:1em" | ^188m1Pb | | colspan="3" style="text-indent:2em" | 2577.2(4)&nbsp;keV | 800(20)&nbsp;ns | IT | ¹⁸⁸Pb | 8− | | |-id=Lead-188m2 | style="text-indent:1em" | ^188m2Pb | | colspan="3" style="text-indent:2em" | 2709.8(5)&nbsp;keV | 94(12)&nbsp;ns | IT | ¹⁸⁸Pb | 12+ | | |-id=Lead-188m3 | style="text-indent:1em" | ^188m3Pb | | colspan="3" style="text-indent:2em" | 4783.4(7)&nbsp;keV | 440(60)&nbsp;ns | IT | ¹⁸⁸Pb | (19−) | | |-id=Lead-189 | rowspan=2|¹⁸⁹Pb | rowspan=2| | rowspan=2 style="text-align:right" | 82 | rowspan=2 style="text-align:right" | 107 | rowspan=2|188.980844(15) | rowspan=2|39(8)&nbsp;s | β⁺ (99.58%) | ¹⁸⁹Tl | rowspan=2|3/2− | rowspan=2| | rowspan=2| |- | α (0.42%) | ¹⁸⁵Hg |-id=Lead-189m1 | rowspan=3 style="text-indent:1em" | ^189m1Pb | rowspan=3| | rowspan=3 colspan="3" style="text-indent:2em" | 40(4)&nbsp;keV | rowspan=3|50.5(21)&nbsp;s | β⁺ (99.6%) | ¹⁸⁹Tl | rowspan=3|13/2+ | rowspan=3| | rowspan=3| |- | α (0.4%) | ¹⁸⁵Hg |- | IT? | ¹⁸⁹Pb |-id=Lead-189m2 | style="text-indent:1em" | ^189m2Pb | | colspan="3" style="text-indent:2em" | 2475(4)&nbsp;keV | 26(5)&nbsp;μs | IT | ¹⁸⁹Pb | 31/2− | | |-id=Lead-190 | rowspan=2|¹⁹⁰Pb | rowspan=2| | rowspan=2 style="text-align:right" | 82 | rowspan=2 style="text-align:right" | 108 | rowspan=2|189.978082(13) | rowspan=2|71(1)&nbsp;s | β⁺ (99.60%) | ¹⁹⁰Tl | rowspan=2|0+ | rowspan=2| | rowspan=2| |- | α (0.40%) | ¹⁸⁶Hg |-id=Lead-190m1 | style="text-indent:1em" | ^190m1Pb | | colspan="3" style="text-indent:2em" | 2614.8(8)&nbsp;keV | 150(14)&nbsp;ns | IT | ¹⁹⁰Pb | 10+ | | |-id=Lead-190m2 | style="text-indent:1em" | ^190m2Pb | | colspan="3" style="text-indent:2em" | 2665(50)#&nbsp;keV | 24.3(21)&nbsp;μs | IT | ¹⁹⁰Pb | (12+) | | |-id=Lead-190m3 | style="text-indent:1em" | ^190m3Pb | | colspan="3" style="text-indent:2em" | 2658.2(8)&nbsp;keV | 7.7(3)&nbsp;μs | IT | ¹⁹⁰Pb | 11− | | |-id=Lead-191 | rowspan=2|¹⁹¹Pb | rowspan=2| | rowspan=2 style="text-align:right" | 82 | rowspan=2 style="text-align:right" | 109 | rowspan=2|190.9782165(71) | rowspan=2|1.33(8)&nbsp;min | β⁺ (99.49%) | ¹⁹¹Tl | rowspan=2|3/2− | rowspan=2| | rowspan=2| |- | α (0.51%) | ¹⁸⁷Hg |-id=Lead-191m1 | rowspan=2 style="text-indent:1em" | ^191m1Pb | rowspan=2| | rowspan=2 colspan="3" style="text-indent:2em" | 58(10)&nbsp;keV | rowspan=2|2.18(8)&nbsp;min | β⁺ (99.98%) | ¹⁹¹Tl | rowspan=2|13/2+ | rowspan=2| | rowspan=2| |- | α (0.02%) | ¹⁸⁷Hg |-id=Lead-191m2 | style="text-indent:1em" | ^191m2Pb | | colspan="3" style="text-indent:2em" | 2659(10)&nbsp;keV | 180(80)&nbsp;ns | IT | ¹⁹¹Pb | 33/2+ | | |-id=Lead-192 | rowspan=2|¹⁹²Pb | rowspan=2| | rowspan=2 style="text-align:right" | 82 | rowspan=2 style="text-align:right" | 110 | rowspan=2|191.9757896(61) | rowspan=2|3.5(1)&nbsp;min | β⁺ (99.99%) | ¹⁹²Tl | rowspan=2|0+ | rowspan=2| | rowspan=2| |- | α (0.0059%) | ¹⁸⁸Hg |-id=Lead-192m1 | style="text-indent:1em" | ^192m1Pb | | colspan="3" style="text-indent:2em" | 2581.1(1)&nbsp;keV | 166(6)&nbsp;ns | IT | ¹⁹²Pb | 10+ | | |-id=Lead-192m2 | style="text-indent:1em" | ^192m2Pb | | colspan="3" style="text-indent:2em" | 2625.1(11)&nbsp;keV | 1.09(4)&nbsp;μs | IT | ¹⁹²Pb | 12+ | | |-id=Lead-192m3 | style="text-indent:1em" | ^192m3Pb | | colspan="3" style="text-indent:2em" | 2743.5(4)&nbsp;keV | 756(14)&nbsp;ns | IT | ¹⁹²Pb | 11− | | |-id=Lead-193 | ¹⁹³Pb | | style="text-align:right" | 82 | style="text-align:right" | 111 | 192.976136(11) | 4#&nbsp;min | β⁺? | ¹⁹³Tl | 3/2−# | | |-id=Lead-193m1 | style="text-indent:1em" | ^193m1Pb | | colspan="3" style="text-indent:2em" | 93(12)&nbsp;keV | 5.8(2)&nbsp;min | β⁺ | ¹⁹³Tl | 13/2+ | | |-id=Lead-193m2 | style="text-indent:1em" | ^193m2Pb | | colspan="3" style="text-indent:2em" | 2707(13)&nbsp;keV | 180(15)&nbsp;ns | IT | ¹⁹³Pb | 33/2+ | | |-id=Lead-194 | rowspan=2|¹⁹⁴Pb | rowspan=2| | rowspan=2 style="text-align:right" | 82 | rowspan=2 style="text-align:right" | 112 | rowspan=2|193.974012(19) | rowspan=2|10.7(6)&nbsp;min | β⁺ | ¹⁹⁴Tl | rowspan=2|0+ | rowspan=2| | rowspan=2| |- | α (7.3×10^{−6}%) | ¹⁹⁰Hg |-id=Lead-194m1 | style="text-indent:1em" | ^194m1Pb | | colspan="3" style="text-indent:2em" | 2628.1(4)&nbsp;keV | 370(13)&nbsp;ns | IT | ¹⁹⁴Pb | 12+ | | |-id=Lead-194m2 | style="text-indent:1em" | ^194m2Pb | | colspan="3" style="text-indent:2em" | 2933.0(4)&nbsp;keV | 133(7)&nbsp;ns | IT | ¹⁹⁴Pb | 11− | | |-id=Lead-195 | ¹⁹⁵Pb | | style="text-align:right" | 82 | style="text-align:right" | 113 | 194.9745162(55) | 15.0(14)&nbsp;min | β⁺ | ¹⁹⁵Tl | 3/2- | | |-id=Lead-195m1 | rowspan=2 style="text-indent:1em" | ^195m1Pb | rowspan=2| | rowspan=2 colspan="3" style="text-indent:2em" | 202.9(7)&nbsp;keV | rowspan=2|15.0(12)&nbsp;min | β⁺ | ¹⁹⁵Tl | rowspan=2|13/2+ | rowspan=2| | rowspan=2| |- | IT? | ¹⁹⁵Pb |-id=Lead-195m2 | style="text-indent:1em" | ^195m2Pb | | colspan="3" style="text-indent:2em" | 1759.0(7)&nbsp;keV | 10.0(7)&nbsp;μs | IT | ¹⁹⁵Pb | 21/2− | | |-id=Lead-195m3 | style="text-indent:1em" | ^195m3Pb | | colspan="3" style="text-indent:2em" | 2901.7(8)&nbsp;keV | 95(20)&nbsp;ns | IT | ¹⁹⁵Pb | 33/2+ | | |-id=Lead-196 | rowspan=2|¹⁹⁶Pb | rowspan=2| | rowspan=2 style="text-align:right" | 82 | rowspan=2 style="text-align:right" | 114 | rowspan=2|195.9727876(83) | rowspan=2|37(3)&nbsp;min | β⁺ | ¹⁹⁶Tl | rowspan=2|0+ | rowspan=2| | rowspan=2| |- | α (<3×10^{−5}%) | ¹⁹²Hg |-id=Lead-196m1 | style="text-indent:1em" | ^196m1Pb | | colspan="3" style="text-indent:2em" | 1797.51(14)&nbsp;keV | 140(14)&nbsp;ns | IT | ¹⁹⁶Pb | 5− | | |-id=Lead-196m2 | style="text-indent:1em" | ^196m2Pb | | colspan="3" style="text-indent:2em" | 2694.6(3)&nbsp;keV | 270(4)&nbsp;ns | IT | ¹⁹⁶Pb | 12+ | | |-id=Lead-197 | ¹⁹⁷Pb | | style="text-align:right" | 82 | style="text-align:right" | 115 | 196.9734347(52) | 8.1(17)&nbsp;min | β⁺ | ¹⁹⁷Tl | 3/2− | | |-id=Lead-197m1 | rowspan=2 style="text-indent:1em" | ^197m1Pb | rowspan=2| | rowspan=2 colspan="3" style="text-indent:2em" | 319.31(11)&nbsp;keV | rowspan=2|42.9(9)&nbsp;min | β⁺ (81%) | ¹⁹⁷Tl | rowspan=2|13/2+ | rowspan=2| | rowspan=2| |- | IT (19%) | ¹⁹⁷Pb |-id=Lead-197m2 | style="text-indent:1em" | ^197m2Pb | | colspan="3" style="text-indent:2em" | 1914.10(25)&nbsp;keV | 1.15(20)&nbsp;μs | IT | ¹⁹⁷Pb | 21/2− | | |-id=Lead-198 | ¹⁹⁸Pb | | style="text-align:right" | 82 | style="text-align:right" | 116 | 197.9720155(94) | 2.4(1)&nbsp;h | β⁺ | ¹⁹⁸Tl | 0+ | | |-id=Lead-198m1 | style="text-indent:1em" | ^198m1Pb | | colspan="3" style="text-indent:2em" | 2141.4(4)&nbsp;keV | 4.12(7)&nbsp;μs | IT | ¹⁹⁸Pb | 7− | | |-id=Lead-198m2 | style="text-indent:1em" | ^198m2Pb | | colspan="3" style="text-indent:2em" | 2231.4(5)&nbsp;keV | 137(10)&nbsp;ns | IT | ¹⁹⁸Pb | 9− | | |-id=Lead-198m3 | style="text-indent:1em" | ^198m3Pb | | colspan="3" style="text-indent:2em" | 2821.7(6)&nbsp;keV | 212(4)&nbsp;ns | IT | ¹⁹⁸Pb | 12+ | | |-id=Lead-199 | ¹⁹⁹Pb | | style="text-align:right" | 82 | style="text-align:right" | 117 | 198.9729126(73) | 90(10)&nbsp;min | β⁺ | ¹⁹⁹Tl | 3/2− | | |-id=Lead-199m1 | rowspan=2 style="text-indent:1em" | ^199m1Pb | rowspan=2| | rowspan=2 colspan="3" style="text-indent:2em" | 429.5(27)&nbsp;keV | rowspan=2|12.2(3)&nbsp;min | IT | ¹⁹⁹Pb | rowspan=2|(13/2+) | rowspan=2| | rowspan=2| |- | β⁺? | ¹⁹⁹Tl |-id=Lead-199m2 | style="text-indent:1em" | ^199m2Pb | | colspan="3" style="text-indent:2em" | 2563.8(27)&nbsp;keV | 10.1(2)&nbsp;μs | IT | ¹⁹⁹Pb | (29/2−) | | |-id=Lead-200 | ²⁰⁰Pb | | style="text-align:right" | 82 | style="text-align:right" | 118 | 199.971819(11) | 21.5(4)&nbsp;h | EC | ²⁰⁰Tl | 0+ | | |-id=Lead-200m1 | style="text-indent:1em" | ^200m1Pb | | colspan="3" style="text-indent:2em" | 2183.3(11)&nbsp;keV | 456(6)&nbsp;ns | IT | ²⁰⁰Pb | (9−) | | |-id=Lead-200m2 | style="text-indent:1em" | ^200m2Pb | | colspan="3" style="text-indent:2em" | 3005.8(12)&nbsp;keV | 198(3)&nbsp;ns | IT | ²⁰⁰Pb | 12+) | | |-id=Lead-201 | ²⁰¹Pb | | style="text-align:right" | 82 | style="text-align:right" | 119 | 200.972870(15) | 9.33(3)&nbsp;h | β⁺ | ²⁰¹Tl | 5/2− | | |-id=Lead-201m1 | rowspan=2 style="text-indent:1em" | ^201m1Pb | rowspan=2| | rowspan=2 colspan="3" style="text-indent:2em" | 629.1(3)&nbsp;keV | rowspan=2|60.8(18)&nbsp;s | IT | ²⁰¹Pb | rowspan=2|13/2+ | rowspan=2| | rowspan=2| |- | β⁺? | ²⁰¹Tl |-id=Lead-201m2 | style="text-indent:1em" | ^201m2Pb | | colspan="3" style="text-indent:2em" | 2953(20)&nbsp;keV | 508(3)&nbsp;ns | IT | ²⁰¹Pb | (29/2−) | | |-id=Lead-202 | ²⁰²Pb | | style="text-align:right" | 82 | style="text-align:right" | 120 | 201.9721516(41) | 5.25(28)×10⁴&nbsp;y | EC | ²⁰²Tl | 0+ | | |-id=Lead-202m1 | rowspan=2 style="text-indent:1em" | ^202m1Pb | rowspan=2| | rowspan=2 colspan="3" style="text-indent:2em" | 2169.85(8)&nbsp;keV | rowspan=2|3.54(2)&nbsp;h | IT (90.5%) | ²⁰²Pb | rowspan=2|9− | rowspan=2| | rowspan=2| |- | β⁺ (9.5%) | ²⁰²Tl |-id=Lead-202m2 | style="text-indent:1em" | ^202m2Pb | | colspan="3" style="text-indent:2em" | 4140(50)#&nbsp;keV | 100(3)&nbsp;ns | IT | ²⁰²Pb | 16+ | | |-id=Lead-202m3 | style="text-indent:1em" | ^202m3Pb | | colspan="3" style="text-indent:2em" | 5300(50)#&nbsp;keV | 108(3)&nbsp;ns | IT | ²⁰²Pb | 19− | | |-id=Lead-203 | ²⁰³Pb | | style="text-align:right" | 82 | style="text-align:right" | 121 | 202.9733906(70) | 51.924(15)&nbsp;h | EC | ²⁰³Tl | 5/2− | | |-id=Lead-203m1 | style="text-indent:1em" | ^203m1Pb | | colspan="3" style="text-indent:2em" | 825.2(3)&nbsp;keV | 6.21(8)&nbsp;s | IT | ²⁰³Pb | 13/2+ | | |-id=Lead-203m2 | style="text-indent:1em" | ^203m2Pb | | colspan="3" style="text-indent:2em" | 2949.2(4)&nbsp;keV | 480(7)&nbsp;ms | IT | ²⁰³Pb | 29/2− | | |-id=Lead-203m3 | style="text-indent:1em" | ^203m3Pb | | colspan="3" style="text-indent:2em" | 2970(50)#&nbsp;keV | 122(4)&nbsp;ns | IT | ²⁰³Pb | 25/2−# | | |-id=Lead-204 | ²⁰⁴Pb | | style="text-align:right" | 82 | style="text-align:right" | 122 | 203.9730435(12) | colspan="3" style="text-align:center;"|Observationally stable | 0+ | 0.014(6) | 0.0000–0.0158 |-id=Lead-204m1 | style="text-indent:1em" | ^204m1Pb | | colspan="3" style="text-indent:2em" | 1274.13(5)&nbsp;keV | 265(6)&nbsp;ns | IT | ²⁰⁴Pb | 4+ | | |-id=Lead-204m2 | style="text-indent:1em" | ^204m2Pb | | colspan="3" style="text-indent:2em" | 2185.88(8)&nbsp;keV | 66.93(10)&nbsp;min | IT | ²⁰⁴Pb | 9− | | |-id=Lead-204m3 | style="text-indent:1em" | ^204m3Pb | | colspan="3" style="text-indent:2em" | 2264.42(6)&nbsp;keV | 490(70)&nbsp;ns | IT | ²⁰⁴Pb | 7− | | |-id=Lead-205 | ²⁰⁵Pb | | style="text-align:right" | 82 | style="text-align:right" | 123 | 204.9744817(12) | 1.70(9)×10⁷&nbsp;y | EC | ²⁰⁵Tl | 5/2− | | |-id=Lead-205m1 | style="text-indent:1em" | ^205m1Pb | | colspan="3" style="text-indent:2em" | 2.329(7)&nbsp;keV | 24.2(4)&nbsp;μs | IT | ²⁰⁵Pb | 1/2− | | |-id=Lead-205m2 | style="text-indent:1em" | ^205m2Pb | | colspan="3" style="text-indent:2em" | 1013.85(3)&nbsp;keV | 5.55(2)&nbsp;ms | IT | ²⁰⁵Pb | 13/2+ | | |-id=Lead-205m3 | style="text-indent:1em" | ^205m3Pb | | colspan="3" style="text-indent:2em" | 3195.8(6)&nbsp;keV | 217(5)&nbsp;ns | IT | ²⁰⁵Pb | 25/2− | | |- | ²⁰⁶Pb | Radium G | style="text-align:right" | 82 | style="text-align:right" | 124 | 205.9744652(12) | colspan="3" style="text-align:center;"|Observationally stable | 0+ | 0.241(30) | 0.0190–0.8673 |-id=Lead-206m1 | style="text-indent:1em" | ^206m1Pb | | colspan="3" style="text-indent:2em" | 2200.16(4)&nbsp;keV | 125(2)&nbsp;μs | IT | ²⁰⁶Pb | 7− | | |-id=Lead-206m2 | style="text-indent:1em" | ^206m2Pb | | colspan="3" style="text-indent:2em" | 4027.3(7)&nbsp;keV | 202(3)&nbsp;ns | IT | ²⁰⁶Pb | 12+ | | |- | ²⁰⁷Pb | Actinium D | style="text-align:right" | 82 | style="text-align:right" | 125 | 206.9758968(12) | colspan="3" style="text-align:center;"|Observationally stable | 1/2− | 0.221(50) | 0.0035–0.2351 |-id=Lead-207m | style="text-indent:1em" | ^207mPb | | colspan="3" style="text-indent:2em" | 1633.356(4)&nbsp;keV | 806(5)&nbsp;ms | IT | ²⁰⁷Pb | 13/2+ | | |-id=Lead-208 | ²⁰⁸Pb | Thorium D | style="text-align:right" | 82 | style="text-align:right" | 126 | 207.9766520(12) | colspan="3" style="text-align:center;"|Observationally stable | 0+ | 0.524(70) | 0.0338–0.9775 |-id=Lead-208m | style="text-indent:1em" | ^208mPb | | colspan="3" style="text-indent:2em" | 4895.23(5)&nbsp;keV | 535(35)&nbsp;ns | IT | ²⁰⁸Pb | 10+ | | |-id=Lead-209 | ²⁰⁹Pb | | style="text-align:right" | 82 | style="text-align:right" | 127 | 208.9810900(19) | 3.235(5)&nbsp;h | β^− | ²⁰⁹Bi | 9/2+ | Trace | |-id=Lead-210 | rowspan=2|²¹⁰Pb | rowspan=2|Radium D<br/>Radiolead<br/>Radio-lead | rowspan=2 style="text-align:right" | 82 | rowspan=2 style="text-align:right" | 128 | rowspan=2|209.9841884(16) | rowspan=2|22.20(22)&nbsp;y | β^− (100%) | ²¹⁰Bi | rowspan=2|0+ | rowspan=2|Trace | rowspan=2| |- | α (1.9×10^{−6}%) | ²⁰⁶Hg |-id=Lead-210m1 | style="text-indent:1em" | ^210m1Pb | | colspan="3" style="text-indent:2em" | 1194.61(18)&nbsp;keV | 92(10)&nbsp;ns | IT | ²¹⁰Pb | 6+ | | |-id=Lead-210m2 | style="text-indent:1em" | ^210m2Pb | | colspan="3" style="text-indent:2em" | 1274.8(3)&nbsp;keV | 201(17)&nbsp;ns | IT | ²¹⁰Pb | 8+ | | |-id=Lead-211 | ²¹¹Pb | Actinium B | style="text-align:right" | 82 | style="text-align:right" | 129 | 210.9887353(24) | 36.1628(25)&nbsp;min | β^− | ²¹¹Bi | 9/2+ | Trace | |-id=Lead-211m | style="text-indent:1em" | ^211mPb | | colspan="3" style="text-indent:2em" | 1719(23)&nbsp;keV | 159(28)&nbsp;ns | IT | ²¹¹Pb | (27/2+) | | |- | ²¹²Pb | Thorium B | style="text-align:right" | 82 | style="text-align:right" | 130 | 211.9918959(20) | 10.627(6)&nbsp;h | β^− | ²¹²Bi | 0+ | Trace | |-id=Lead-212m | style="text-indent:1em" | ^212mPb | | colspan="3" style="text-indent:2em" | 1335(2)&nbsp;keV | 6.0(8)&nbsp;μs | IT | ²¹²Pb | 8+# | | |-id=Lead-213 | ²¹³Pb | | style="text-align:right" | 82 | style="text-align:right" | 131 | 212.9965608(75) | 10.2(3)&nbsp;min | β^− | ²¹³Bi | (9/2+) | Trace | |-id=Lead-213m | style="text-indent:1em" | ^213mPb | | colspan="3" style="text-indent:2em" | 1331.0(17)&nbsp;keV | 260(20)&nbsp;ns | IT | ²¹³Pb | (21/2+) | | |-id=Lead-214 | ²¹⁴Pb | Radium B | style="text-align:right" | 82 | style="text-align:right" | 132 | 213.9998035(21) | 27.06(7)&nbsp;min | β^− | ²¹⁴Bi | 0+ | Trace | |-id=Lead-214m | style="text-indent:1em" | ^214mPb | | colspan="3" style="text-indent:2em" | 1420(20)&nbsp;keV | 6.2(3)&nbsp;μs | IT | ²¹⁴Pb | 8+# | | |-id=Lead-215 | ²¹⁵Pb | | style="text-align:right" | 82 | style="text-align:right" | 133 | 215.004662(57) | 142(11)&nbsp;s | β^− | ²¹⁵Bi | 9/2+# | | |-id=Lead-216 | ²¹⁶Pb | | style="text-align:right" | 82 | style="text-align:right" | 134 | 216.00806(22)# | 1.66(20)&nbsp;min | β^− | ²¹⁶Bi | 0+ | | |-id=Lead-216m | style="text-indent:1em" | ^216mPb | | colspan="3" style="text-indent:2em" | 1514(20)&nbsp;keV | 400(40)&nbsp;ns | IT | ²¹⁶Pb | 8+# | | |-id=Lead-217 | ²¹⁷Pb | | style="text-align:right" | 82 | style="text-align:right" | 135 | 217.01316(32)# | 19.9(53)&nbsp;s | β^− | ²¹⁷Bi | 9/2+# | | |-id=Lead-218 | ²¹⁸Pb | | style="text-align:right" | 82 | style="text-align:right" | 136 | 218.01678(32)# | 14.8(68)&nbsp;s | β^− | ²¹⁸Bi | 0+ | | |-id=Lead-219 | ²¹⁹Pb | | style="text-align:right" | 82 | style="text-align:right" | 137 | 219.02214(43)# | 3#&nbsp;s<br />[>300&nbsp;ns] | β^−? | ²¹⁹Bi | 11/2+# | | |-id=Lead-220 | ²²⁰Pb | | style="text-align:right" | 82 | style="text-align:right" | 138 | 220.02591(43)# | 1#&nbsp;s<br />[>300&nbsp;ns] | β^−? | ²²⁰Bi | 0+ | |

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 rarer ²⁰⁶Tl (radium E^II) by beta decay.

Lead-206 has been proposed for use in fast breeder nuclear fission reactor coolant over the use of natural lead mixture (which also includes other stable lead isotopes) as a mechanism to improve neutron economy and greatly suppress unwanted production of highly radioactive byproducts.

Lead-204, -207, and -208

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) based on the relative abundance of lead-204 to other isotopes.

²⁰⁷Pb is the end of the actinium series from ²³⁵U.

²⁰⁸Pb is the end of the thorium series from ²³²Th. 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. ²⁰⁸Pb is the heaviest known stable nuclide and also the heaviest known doubly magic nucleus, as Z = 82 and N = 126 correspond to closed nuclear shells. As a consequence of this particularly stable configuration, its neutron capture cross section is very low (even lower than that of deuterium in the thermal spectrum), making it of interest for lead-cooled fast reactors.

In 2025 a published study suggested that the nucleus of ²⁰⁸Pb is not perfectly spherical as previously believed, but rather is a "prolate spheroid", more commonly described as the shape of a rugby ball.

Lead-210

Lead-210 (²¹⁰Pb) is a radiogenic isotope of lead, found in the decay chain of uranium-238. It is a beta emitter with a half-life of 22.20 years. In addition to dating recent sediments, ²¹⁰Pb is widely applied for studying soil erosion and sedimentation dynamics in agricultural and natural environments. The unsupported or excess component (²¹⁰Pb_ex), derived from atmospheric fallout of radon-222 decay products, accumulates in surface soils and decays with a half-life of 22.3 years. Its depth-dependent activity profile enables reconstruction of soil redistribution over the past century.

Because ²¹⁰Pb deposition is continuous and globally widespread, the method provides a long-term perspective that complements the medium-term records obtained from anthropogenic radionuclides such as ¹³⁷Cs. It has been used to quantify erosion and deposition rates, assess land degradation, and evaluate soil conservation practices, offering valuable data for geomorphic and environmental research.

The radiation emitted by lead-210 can cause issues for some particle physics experiments which has resulted in the use of roman lead in such applications where the lead-210 has had time to decay to far lower levels.

Lead-212

Lead-212 (²¹²Pb) is a radioactive isotope of lead that has gained significant attention in nuclear medicine, particularly in targeted alpha therapy (TAT). This isotope is part of the thorium decay series and serves as an important intermediate in various radioactive decay chains. ²¹²Pb is produced through the decay of radon-220 (²²⁰Rn), an intermediate product of thorium-228 (²²⁸Th) decay. It undergoes radioactive decay through beta emission to form bismuth-212 (²¹²Bi), which further decays to emit alpha particles. This decay chain is particularly important in medical applications, as it is an in-vivo generator system of alpha particles, that can be utilized for therapeutic purposes, particularly TAT, by delivering potent, localized radiation to cancer cells.

The isotope is part of the thorium decay series, which begins with natural thorium-232. Its beta decay (10.627 hours) results in the formation of bismuth-212 (²¹²Bi), which then emits alpha particles (6.1 MeV), crucial for the effectiveness of TAT in cancer treatment.

While in aqueous solutions, free Pb²⁺ tends to hydrolyze under physiological pH conditions to form species like Pb(OH)⁺, which can impact its biodistribution if not properly chelated, chelator-modified complexes have demonstrated high stability in saline and serum environments for extended periods (e.g., 24–72 hours), which is critical for therapeutic applications.

Lead-212 can be synthesized through several methods, with generator-based production utilizing the decay of ²²⁸Th being the most common. This includes direct extraction from ²²⁸Th, ²²⁴Ra/²¹²Pb generators, and ²²⁰Rn-based generation. Each of these methods has its own advantages and complexities. These various production routes cater to different industrial needs and regulatory considerations in the field of radioisotope production.

See also

Daughter products other than lead

• Isotopes of bismuth
• Isotopes of thallium
• Isotopes of mercury

References