Isotopes of lead
Encyclopedia
Lead
Lead
Lead is a main-group element in the carbon group with the symbol Pb and atomic number 82. Lead is a soft, malleable poor metal. It is also counted as one of the heavy metals. Metallic lead has a bluish-white color after being freshly cut, but it soon tarnishes to a dull grayish color when exposed...

 (Pb) has four stable isotope
Isotope
Isotopes are variants of atoms of a particular chemical element, which have differing numbers of neutrons. Atoms of a particular element by definition must contain the same number of protons but may have a distinct number of neutrons which differs from atom to atom, without changing the designation...

s: 204Pb, 206Pb, 207Pb, 208Pb. Lead-204 is entirely a primordial nuclide
Primordial nuclide
In geochemistry and geonuclear physics, primordial nuclides or primordial isotopes are nuclides found on the earth that have existed in their current form since before Earth was formed. Only 288 such nuclides are known...

 and is not a radiogenic
Radiogenic nuclide
A radiogenic nuclide is a nuclide that is produced by a process of radioactive decay. It may itself be radioactive, or stable.Radiogenic nuclides form some of the most important tools in geology...

 nuclide. The three isotopes lead-206, lead-207, and lead-208 represent the ends of three decay chain
Decay chain
In nuclear science, the decay chain refers to the radioactive decay of different discrete radioactive decay products as a chained series of transformations...

s called the uranium series (or radium series), the actinium series, and the thorium series, respectively. These series represent the decay chain
Decay chain
In nuclear science, the decay chain refers to the radioactive decay of different discrete radioactive decay products as a chained series of transformations...

 products of long-lived primoridal U-238, U-235, and Th-232, respectively. However, each of them also occurs, to some extent, as primordial isotopes which 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
Lead-lead dating
Lead-lead dating is a method for dating geological samples, normally based on 'whole-rock' samples of material such as granite. For most dating requirements it has been superseded by uranium-lead dating , but in certain specialized situations it is more important than U-Pb dating.-Decay equations...

 and uranium-lead dating
Uranium-lead dating
Uranium-lead is one of the oldest and most refined of the radiometric dating schemes, with a routine age range of about 1 million years to over 4.5 billion years, and with routine precisions in the 0.1-1 percent range...

).

The longest-lived radioisotopes are 205Pb with a half-life
Half-life
Half-life, abbreviated t½, is the period of time it takes for the amount of a substance undergoing decay to decrease by half. The name was originally used to describe a characteristic of unstable atoms , but it may apply to any quantity which follows a set-rate decay.The original term, dating to...

 of ~15.3 million years and 202Pb with a half-life of ~53,000 years. Of naturally-occurring radioisotopes, the longest half-life is 210Pb with a half-life of 22.20 years.

The standard atomic mass (abundance-weighted average of the stable isotopes) is 207.2(1) u. Lead is the element with the heaviest stable isotope, 208Pb. (The more massive 209Bi
Bismuth-209
Bismuth-209 is the isotope of bismuth with the longest half-life. It has 83 protons and 126 neutrons, and an atomic mass of 208.9803987 u. All primordial bismuth is of this isotope...

, 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.

Lead-206

206Pb is the final step in the decay chain
Decay chain
In nuclear science, the decay chain refers to the radioactive decay of different discrete radioactive decay products as a chained series of transformations...

 of 238U
Uranium-238
Uranium-238 is the most common isotope of uranium found in nature. It is not fissile, but is a fertile material: it can capture a slow neutron and after two beta decays become fissile plutonium-239...

, 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
Alpha decay
Alpha decay is a type of radioactive decay in which an atomic nucleus emits an alpha particle and thereby transforms into an atom with a mass number 4 less and atomic number 2 less...

, and the much more rare 206Tl
Isotopes of thallium
Thallium has 37 isotopes which have atomic masses that range from 176 to 212. 203Tl and 205Tl are the only stable isotopes and 204Tl is the most stable radioisotope with a half-life of 3.78 years...

 (radium EII) by beta decay
Beta decay
In nuclear physics, beta decay is a type of radioactive decay in which a beta particle is emitted from an atom. There are two types of beta decay: beta minus and beta plus. In the case of beta decay that produces an electron emission, it is referred to as beta minus , while in the case of a...

.

Lead 207, 208, and 204

207Pb is the end of the Actinium series from 235
Uranium-235
- References :* .* DOE Fundamentals handbook: Nuclear Physics and Reactor theory , .* A piece of U-235 the size of a grain of rice can produce energy equal to that contained in three tons of coal or fourteen barrels of oil. -External links:* * * one of the earliest articles on U-235 for the...

U
Uranium-235
- References :* .* DOE Fundamentals handbook: Nuclear Physics and Reactor theory , .* A piece of U-235 the size of a grain of rice can produce energy equal to that contained in three tons of coal or fourteen barrels of oil. -External links:* * * one of the earliest articles on U-235 for the...

.

208Pb is the end of the Thorium series from 232Th.

204Pb is entirely primordial
Primordial nuclide
In geochemistry and geonuclear physics, primordial nuclides or primordial isotopes are nuclides found on the earth that have existed in their current form since before Earth was formed. Only 288 such nuclides are known...

, 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

{| class="wikitable" style="font-size:95%; white-space:nowrap"
! rowspan="2" | nuclide
symbol
! rowspan="2" | historic
name
! Z(p
Proton
The proton is a subatomic particle with the symbol or and a positive electric charge of 1 elementary charge. One or more protons are present in the nucleus of each atom, along with neutrons. The number of protons in each atom is its atomic number....

)
! N(n
Neutron
The neutron is a subatomic hadron particle which has the symbol or , no net electric charge and a mass slightly larger than that of a proton. With the exception of hydrogen, nuclei of atoms consist of protons and neutrons, which are therefore collectively referred to as nucleons. The number of...

)
!  
isotopic mass (u)
 
! rowspan="2" | half-life
! rowspan="2" | decay
mode(s)Abbreviations:
EC: Electron capture
Electron capture
Electron capture is a process in which a proton-rich nuclide absorbs an inner atomic electron and simultaneously emits a neutrino...


IT: Isomeric transition
Isomeric transition
An isomeric transition is a radioactive decay process that involves emission of a gamma ray from an atom where the nucleus is in an excited metastable state, referred to in its excited state, as a nuclear isomer....


! rowspan="2" | daughter
isotope(s)Bold for stable isotopes, bold italics for nearly-stable isotopes (half-life longer than the age of the universe
Age of the universe
The age of the universe is the time elapsed since the Big Bang posited by the most widely accepted scientific model of cosmology. The best current estimate of the age of the universe is 13.75 ± 0.13 billion years within the Lambda-CDM concordance model...

)

! rowspan="2" | nuclear
spin
! rowspan="2" | representative
isotopic
composition
(mole fraction)
! rowspan="2" | range of natural
variation
(mole fraction)
|-
! colspan="3" | excitation energy
|-
| 178Pb
|
| style="text-align:right" | 82
| style="text-align:right" | 96
| 178.003830(26)
| 0.23(15) ms
|
|
| 0+
|
|-
| 179Pb
|
| style="text-align:right" | 82
| style="text-align:right" | 97
| 179.00215(21)#
| 3# ms
|
|
| 5/2-#
|
|
|-
| 180Pb
|
| style="text-align:right" | 82
| style="text-align:right" | 98
| 179.997918(22)
| 4.5(11) ms
|
|
| 0+
|
|
|-
| rowspan=2|181Pb
| rowspan=2|
| rowspan=2 style="text-align:right" | 82
| rowspan=2 style="text-align:right" | 99
| rowspan=2|180.99662(10)
| rowspan=2|45(20) ms
| α
Alpha decay
Alpha decay is a type of radioactive decay in which an atomic nucleus emits an alpha particle and thereby transforms into an atom with a mass number 4 less and atomic number 2 less...

 (98%)
| 177Hg
| rowspan=2|5/2-#
| rowspan=2|
| rowspan=2|
|-
| β+
Beta decay
In nuclear physics, beta decay is a type of radioactive decay in which a beta particle is emitted from an atom. There are two types of beta decay: beta minus and beta plus. In the case of beta decay that produces an electron emission, it is referred to as beta minus , while in the case of a...

 (2%)
| 181Tl
|-
| rowspan=2|182Pb
| rowspan=2|
| rowspan=2 style="text-align:right" | 82
| rowspan=2 style="text-align:right" | 100
| rowspan=2|181.992672(15)
| rowspan=2|60(40) ms
[55(+40-35) ms]
| α (98%)
| 178Hg
| rowspan=2|0+
| rowspan=2|
| rowspan=2|
|-
| β+ (2%)
| 182Tl
|-
| rowspan=2|183Pb
| rowspan=2|
| rowspan=2 style="text-align:right" | 82
| rowspan=2 style="text-align:right" | 101
| rowspan=2|182.99187(3)
| rowspan=2|535(30) ms
| α (94%)
| 179Hg
| rowspan=2|(3/2-)
| rowspan=2|
| rowspan=2|
|-
| β+ (6%)
| 183Tl
|-
| rowspan=2 style="text-indent:1em" | 183mPb
| rowspan=2|
| rowspan=2 colspan="3" style="text-indent:2em" | 94(8) keV
| rowspan=2|415(20) ms
| α
| 179Hg
| rowspan=2|(13/2+)
| rowspan=2|
| rowspan=2|
|-
| β+ (rare)
| 183Tl
|-
| rowspan=2|184Pb
| rowspan=2|
| rowspan=2 style="text-align:right" | 82
| rowspan=2 style="text-align:right" | 102
| rowspan=2|183.988142(15)
| rowspan=2|490(25) ms
| α
| 180Hg
| rowspan=2|0+
| rowspan=2|
| rowspan=2|
|-
| β+ (rare)
| 184Tl
|-
| 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) s
| α
| 181Hg
| rowspan=2|3/2-
| rowspan=2|
| rowspan=2|
|-
| β+ (rare)
| 185Tl
|-
| rowspan=2 style="text-indent:1em" | 185mPb
| rowspan=2|
| rowspan=2 colspan="3" style="text-indent:2em" | 60(40)# keV
| rowspan=2|4.07(15) s
| α
| 181Hg
| rowspan=2|13/2+
| rowspan=2|
| rowspan=2|
|-
| β+ (rare)
| 185Tl
|-
| 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) s
| α (56%)
| 182Hg
| rowspan=2|0+
| rowspan=2|
| rowspan=2|
|-
| β+ (44%)
| 186Tl
|-
| rowspan=2|187Pb
| rowspan=2|
| rowspan=2 style="text-align:right" | 82
| rowspan=2 style="text-align:right" | 105
| rowspan=2|186.983918(9)
| rowspan=2|15.2(3) s
| β+
| 187Tl
| rowspan=2|(3/2-)
| rowspan=2|
| rowspan=2|
|-
| α
| 183Hg
|-
| rowspan=2 style="text-indent:1em" | 187mPb
| rowspan=2|
| rowspan=2 colspan="3" style="text-indent:2em" | 11(11) keV
| rowspan=2|18.3(3) s
| β+ (98%)
| 187Tl
| rowspan=2|(13/2+)
| rowspan=2|
| rowspan=2|
|-
| α (2%)
| 183Hg
|-
| rowspan=2|188Pb
| rowspan=2|
| rowspan=2 style="text-align:right" | 82
| rowspan=2 style="text-align:right" | 106
| rowspan=2|187.980874(11)
| rowspan=2|25.5(1) s
| β+ (91.5%)
| 188Tl
| rowspan=2|0+
| rowspan=2|
| rowspan=2|
|-
| α (8.5%)
| 184Hg
|-
| style="text-indent:1em" | 188m1Pb
|
| colspan="3" style="text-indent:2em" | 2578.2(7) keV
| 830(210) ns
|
|
| (8-)
|
|
|-
| style="text-indent:1em" | 188m2Pb
|
| colspan="3" style="text-indent:2em" | 2800(50) keV
| 797(21) ns
|
|
|
|
|
|-
| 189Pb
|
| style="text-align:right" | 82
| style="text-align:right" | 107
| 188.98081(4)
| 51(3) s
| β+
| 189Tl
| (3/2-)
|
|
|-
| rowspan=2 style="text-indent:1em" | 189mPb
| rowspan=2|
| rowspan=2 colspan="3" style="text-indent:2em" | 40(30)# keV
| rowspan=2|1# min
| β+ (99.6%)
| 189Tl
| rowspan=2|(13/2+)
| rowspan=2|
| rowspan=2|
|-
| α (.4%)
| 185Hg
|-
| 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) s
| β+ (99.1%)
| 190Tl
| rowspan=2|0+
| rowspan=2|
| rowspan=2|
|-
| α (.9%)
| 186Hg
|-
| style="text-indent:1em" | 190m1Pb
|
| colspan="3" style="text-indent:2em" | 2614.8(8) keV
| 150 ns
|
|
| (10)+
|
|
|-
| style="text-indent:1em" | 190m2Pb
|
| colspan="3" style="text-indent:2em" | 2618(20) keV
| 25 µs
|
|
| (12+)
|
|
|-
| style="text-indent:1em" | 190m3Pb
|
| colspan="3" style="text-indent:2em" | 2658.2(8) keV
| 7.2(6) µs
|
|
| (11)-
|
|
|-
| rowspan=2|191Pb
| rowspan=2|
| rowspan=2 style="text-align:right" | 82
| rowspan=2 style="text-align:right" | 109
| rowspan=2|190.97827(4)
| rowspan=2|1.33(8) min
| β+ (99.987%)
| 191Tl
| rowspan=2|(3/2-)
| rowspan=2|
| rowspan=2|
|-
| α (.013%)
| 187Hg
|-
| rowspan=2 style="text-indent:1em" | 191mPb
| rowspan=2|
| rowspan=2 colspan="3" style="text-indent:2em" | 20(50) keV
| rowspan=2|2.18(8) min
| β+ (99.98%)
| 191Tl
| rowspan=2|13/2(+)
| rowspan=2|
| rowspan=2|
|-
| α (.02%)
| 187Hg
|-
| rowspan=2|192Pb
| rowspan=2|
| rowspan=2 style="text-align:right" | 82
| rowspan=2 style="text-align:right" | 110
| rowspan=2|191.975785(14)
| rowspan=2|3.5(1) min
| β+ (99.99%)
| 192Tl
| rowspan=2|0+
| rowspan=2|
| rowspan=2|
|-
| α (.0061%)
| 188Hg
|-
| style="text-indent:1em" | 192m1Pb
|
| colspan="3" style="text-indent:2em" | 2581.1(1) keV
| 164(7) ns
|
|
| (10)+
|
|
|-
| style="text-indent:1em" | 192m2Pb
|
| colspan="3" style="text-indent:2em" | 2625.1(11) keV
| 1.1(5) µs
|
|
| (12+)
|
|
|-
| style="text-indent:1em" | 192m3Pb
|
| colspan="3" style="text-indent:2em" | 2743.5(4) keV
| 756(21) ns
|
|
| (11)-
|
|
|-
| 193Pb
|
| style="text-align:right" | 82
| style="text-align:right" | 111
| 192.97617(5)
| 5# min
| β+
| 193Tl
| (3/2-)
|
|
|-
| style="text-indent:1em" | 193m1Pb
|
| colspan="3" style="text-indent:2em" | 130(80)# keV
| 5.8(2) min
| β+
| 193Tl
| 13/2(+)
|
|
|-
| style="text-indent:1em" | 193m2Pb
|
| colspan="3" style="text-indent:2em" | 2612.5(5)+X keV
| 135(+25-15) ns
|
|
| (33/2+)
|
|
|-
| 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|12.0(5) min
| β+ (100%)
| 194Tl
| rowspan=2|0+
| rowspan=2|
| rowspan=2|
|-
| α (7.3×10−6%)
| 190Hg
|-
| 195Pb
|
| style="text-align:right" | 82
| style="text-align:right" | 113
| 194.974542(25)
| ~15 min
| β+
| 195Tl
| 3/2#-
|
|
|-
| style="text-indent:1em" | 195m1Pb
|
| colspan="3" style="text-indent:2em" | 202.9(7) keV
| 15.0(12) min
| β+
| 195Tl
| 13/2+
|
|
|-
| style="text-indent:1em" | 195m2Pb
|
| colspan="3" style="text-indent:2em" | 1759.0(7) keV
| 10.0(7) µs
|
|
| 21/2-
|
|
|-
| rowspan=2|196Pb
| rowspan=2|
| rowspan=2 style="text-align:right" | 82
| rowspan=2 style="text-align:right" | 114
| rowspan=2|195.972774(15)
| rowspan=2|37(3) min
| β+
| 196Tl
| rowspan=2|0+
| rowspan=2|
| rowspan=2|
|-
| α (3×10−5%)
| 192Hg
|-
| style="text-indent:1em" | 196m1Pb
|
| colspan="3" style="text-indent:2em" | 1049.20(9) keV
| <100 ns
|
|
| 2+
|
|
|-
| style="text-indent:1em" | 196m2Pb
|
| colspan="3" style="text-indent:2em" | 1738.27(12) keV
| <1 µs
|
|
| 4+
|
|
|-
| style="text-indent:1em" | 196m3Pb
|
| colspan="3" style="text-indent:2em" | 1797.51(14) keV
| 140(14) ns
|
|
| 5-
|
|
|-
| style="text-indent:1em" | 196m4Pb
|
| colspan="3" style="text-indent:2em" | 2693.5(5) keV
| 270(4) ns
|
|
| (12+)
|
|
|-
| 197Pb
|
| style="text-align:right" | 82
| style="text-align:right" | 115
| 196.973431(6)
| 8.1(17) min
| β+
| 197Tl
| 3/2-
|
|
|-
| rowspan=3 style="text-indent:1em" | 197m1Pb
| rowspan=3|
| rowspan=3 colspan="3" style="text-indent:2em" | 319.31(11) keV
| rowspan=3|42.9(9) min
| β+ (81%)
| 197Tl
| rowspan=3|13/2+
| rowspan=3|
| rowspan=3|
|-
| IT (19%)
| 197Pb
|-
| α (3×10−4%)
| 193Hg
|-
| style="text-indent:1em" | 197m2Pb
|
| colspan="3" style="text-indent:2em" | 1914.10(25) keV
| 1.15(20) µs
|
|
| 21/2-
|
|
|-
| 198Pb
|
| style="text-align:right" | 82
| style="text-align:right" | 116
| 197.972034(16)
| 2.4(1) h
| β+
| 198Tl
| 0+
|
|
|-
| style="text-indent:1em" | 198m1Pb
|
| colspan="3" style="text-indent:2em" | 2141.4(4) keV
| 4.19(10) µs
|
|
| (7)-
|
|
|-
| style="text-indent:1em" | 198m2Pb
|
| colspan="3" style="text-indent:2em" | 2231.4(5) keV
| 137(10) ns
|
|
| (9)-
|
|
|-
| style="text-indent:1em" | 198m3Pb
|
| colspan="3" style="text-indent:2em" | 2820.5(7) keV
| 212(4) ns
|
|
| (12)+
|
|
|-
| 199Pb
|
| style="text-align:right" | 82
| style="text-align:right" | 117
| 198.972917(28)
| 90(10) min
| β+
| 199Tl
| 3/2-
|
|
|-
| rowspan=2 style="text-indent:1em" | 199m1Pb
| rowspan=2|
| rowspan=2 colspan="3" style="text-indent:2em" | 429.5(27) keV
| rowspan=2|12.2(3) min
| IT (93%)
| 199Pb
| rowspan=2|(13/2+)
| rowspan=2|
| rowspan=2|
|-
| β+ (7%)
| 199Tl
|-
| style="text-indent:1em" | 199m2Pb
|
| colspan="3" style="text-indent:2em" | 2563.8(27) keV
| 10.1(2) µs
|
|
| (29/2-)
|
|
|-
| 200Pb
|
| style="text-align:right" | 82
| style="text-align:right" | 118
| 199.971827(12)
| 21.5(4) h
| β+
| 200Tl
| 0+
|
|
|-
| rowspan=2|201Pb
| rowspan=2|
| rowspan=2 style="text-align:right" | 82
| rowspan=2 style="text-align:right" | 119
| rowspan=2|200.972885(24)
| rowspan=2|9.33(3) h
| IT (99%)
| 201Pb
| rowspan=2|5/2-
| rowspan=2|
| rowspan=2|
|-
| β+ (1%)
| 201Tl
|-
| style="text-indent:1em" | 201m1Pb
|
| colspan="3" style="text-indent:2em" | 629.14(17) keV
| 61(2) s
|
|
| 13/2+
|
|
|-
| style="text-indent:1em" | 201m2Pb
|
| colspan="3" style="text-indent:2em" | 2718.5+X keV
| 508(5) ns
|
|
| (29/2-)
|
|
|-
| rowspan=2|202Pb
| rowspan=2|
| rowspan=2 style="text-align:right" | 82
| rowspan=2 style="text-align:right" | 120
| rowspan=2|201.972159(9)
| rowspan=2|52.5(28)×103 a
| EC
Electron capture
Electron capture is a process in which a proton-rich nuclide absorbs an inner atomic electron and simultaneously emits a neutrino...

 (99%)
| 202Tl
| rowspan=2|0+
| rowspan=2|
| rowspan=2|
|-
| α (1%)
| 198Hg
|-
| rowspan=2 style="text-indent:1em" | 202m1Pb
| rowspan=2|
| rowspan=2 colspan="3" style="text-indent:2em" | 2169.83(7) keV
| rowspan=2|3.53(1) h
| IT (90.5%)
| 202Pb
| rowspan=2|9-
| rowspan=2|
| rowspan=2|
|-
| EC (9.5%)
| 202Tl
|-
| style="text-indent:1em" | 202m2Pb
|
| colspan="3" style="text-indent:2em" | 4142.9(11) keV
| 110(5) ns
|
|
| (16+)
|
|
|-
| style="text-indent:1em" | 202m3Pb
|
| colspan="3" style="text-indent:2em" | 5345.9(13) keV
| 107(5) ns
|
|
| (19-)
|
|
|-
| 203Pb
|
| style="text-align:right" | 82
| style="text-align:right" | 121
| 202.973391(7)
| 51.873(9) h
| EC
| 203Tl
| 5/2-
|
|
|-
| style="text-indent:1em" | 203m1Pb
|
| colspan="3" style="text-indent:2em" | 825.20(9) keV
| 6.21(8) s
| IT
| 203Pb
| 13/2+
|
|
|-
| style="text-indent:1em" | 203m2Pb
|
| colspan="3" style="text-indent:2em" | 2949.47(22) keV
| 480(7) ms
|
|
| 29/2-
|
|
|-
| style="text-indent:1em" | 203m3Pb
|
| colspan="3" style="text-indent:2em" | 2923.4+X keV
| 122(4) ns
|
|
| (25/2-)
|
|
|-
| 204PbUsed in lead-lead dating
Lead-lead dating
Lead-lead dating is a method for dating geological samples, normally based on 'whole-rock' samples of material such as granite. For most dating requirements it has been superseded by uranium-lead dating , but in certain specialized situations it is more important than U-Pb dating.-Decay equations...


|
| style="text-align:right" | 82
| style="text-align:right" | 122
| 203.9730436(13)
| colspan=3 align=center|Observationally StableBelieved to undergo α decay to 200Hg with a half-life
Half-life
Half-life, abbreviated t½, is the period of time it takes for the amount of a substance undergoing decay to decrease by half. The name was originally used to describe a characteristic of unstable atoms , but it may apply to any quantity which follows a set-rate decay.The original term, dating to...

 over 140×1015 years

| 0+
| 0.014(1)
| 0.0104-0.0165
|-
| style="text-indent:1em" | 204m1Pb
|
| colspan="3" style="text-indent:2em" | 1274.00(4) keV
| 265(10) ns
|
|
| 4+
|
|
|-
| style="text-indent:1em" | 204m2Pb
|
| colspan="3" style="text-indent:2em" | 2185.79(5) keV
| 67.2(3) min
|
|
| 9-
|
|
|-
| style="text-indent:1em" | 204m3Pb
|
| colspan="3" style="text-indent:2em" | 2264.33(4) keV
| 0.45(+10-3) µs
|
|
| 7-
|
|
|-
| 205Pb
|
| style="text-align:right" | 82
| style="text-align:right" | 123
| 204.9744818(13)
| 15.3(7)×106 a
| EC
| 205Tl
| 5/2-
|
|
|-
| style="text-indent:1em" | 205m1Pb
|
| colspan="3" style="text-indent:2em" | 2.329(7) keV
| 24.2(4) µs
|
|
| 1/2-
|
|
|-
| style="text-indent:1em" | 205m2Pb
|
| colspan="3" style="text-indent:2em" | 1013.839(13) keV
| 5.55(2) ms
|
|
| 13/2+
|
|
|-
| style="text-indent:1em" | 205m3Pb
|
| colspan="3" style="text-indent:2em" | 3195.7(5) keV
| 217(5) ns
|
|
| 25/2-
|
|
|-
| 206PbFinal decay product
Decay product
In nuclear physics, a decay product is the remaining nuclide left over from radioactive decay. Radioactive decay often involves a sequence of steps...

 of 4n+2 decay chain
Decay chain
In nuclear science, the decay chain refers to the radioactive decay of different discrete radioactive decay products as a chained series of transformations...

 (the Radium or Uranium series)

| Radium G
| style="text-align:right" | 82
| style="text-align:right" | 124
| 205.9744653(13)
| colspan=3 align=center|Observationally StableBelieved to undergo α decay to 202Hg
| 0+
| 0.241(1)
| 0.2084-0.2748
|-
| style="text-indent:1em" | 206m1Pb
|
| colspan="3" style="text-indent:2em" | 2200.14(4) keV
| 125(2) µs
|
|
| 7-
|
|
|-
| style="text-indent:1em" | 206m2Pb
|
| colspan="3" style="text-indent:2em" | 4027.3(7) keV
| 202(3) ns
|
|
| 12+
|
|
|-
| 207PbFinal decay product of 4n+3 decay chain (the Actinium series)
| Actinium D
| style="text-align:right" | 82
| style="text-align:right" | 125
| 206.9758969(13)
| colspan=3 align=center|Observationally StableBelieved to undergo α decay to 203Hg ({citation needed}}
| 1/2-
| 0.221(1)
| 0.1762-0.2365
|-
| style="text-indent:1em" | 207mPb
|
| colspan="3" style="text-indent:2em" | 1633.368(5) keV
| 806(6) ms
| IT
| 207Pb
| 13/2+
|
|
|-
| 208PbFinal decay product of 4n decay chain (the Thorium series)
| Thorium D
| style="text-align:right" | 82
| style="text-align:right" | 126
| 207.9766521(13)
| colspan=3 align=center|Observationally StableHeaviest observationally stable nuclide, believed to undergo α decay to 204Hg with a half-life
Half-life
Half-life, abbreviated t½, is the period of time it takes for the amount of a substance undergoing decay to decrease by half. The name was originally used to describe a characteristic of unstable atoms , but it may apply to any quantity which follows a set-rate decay.The original term, dating to...

 over 2×1019 years

| 0+
| 0.524(1)
| 0.5128-0.5621
|-
| style="text-indent:1em" | 208mPb
|
| colspan="3" style="text-indent:2em" | 4895(2) keV
| 500(10) ns
|
|
| 10+
|
|
|-
| 209Pb
|
| style="text-align:right" | 82
| style="text-align:right" | 127
| 208.9810901(19)
| 3.253(14) h
| β-
| 209Bi
| 9/2+
|
|
|-
| rowspan=2|210Pb
| rowspan=2|Radium D
Radiolead
Radio-lead
| rowspan=2 style="text-align:right" | 82
| rowspan=2 style="text-align:right" | 128
| rowspan=2|209.9841885(16)
| rowspan=2|22.20(22) a
| β- (100%)
| 210Bi
| rowspan=2|0+
| rowspan=2|TraceIntermediate decay product
Decay product
In nuclear physics, a decay product is the remaining nuclide left over from radioactive decay. Radioactive decay often involves a sequence of steps...

 of 238U
Uranium-238
Uranium-238 is the most common isotope of uranium found in nature. It is not fissile, but is a fertile material: it can capture a slow neutron and after two beta decays become fissile plutonium-239...


| rowspan=2|
|-
| α (1.9×10−6%)
| 206Hg
|-
| style="text-indent:1em" | 210mPb
|
| colspan="3" style="text-indent:2em" | 1278(5) keV
| 201(17) ns
|
|
| 8+
|
|
|-
| 211Pb
| Actinium B
| style="text-align:right" | 82
| style="text-align:right" | 129
| 210.9887370(29)
| 36.1(2) min
| β-
| 211Bi
| 9/2+
| TraceIntermediate decay product
Decay product
In nuclear physics, a decay product is the remaining nuclide left over from radioactive decay. Radioactive decay often involves a sequence of steps...

 of 235U
Uranium-235
- References :* .* DOE Fundamentals handbook: Nuclear Physics and Reactor theory , .* A piece of U-235 the size of a grain of rice can produce energy equal to that contained in three tons of coal or fourteen barrels of oil. -External links:* * * one of the earliest articles on U-235 for the...


|
|-
| 212Pb
| Thorium B
| style="text-align:right" | 82
| style="text-align:right" | 130
| 211.9918975(24)
| 10.64(1) h
| β-
| 212Bi
| 0+
| TraceIntermediate decay product
Decay product
In nuclear physics, a decay product is the remaining nuclide left over from radioactive decay. Radioactive decay often involves a sequence of steps...

of 232Th

|
|-
| style="text-indent:1em" | 212mPb
|
| colspan="3" style="text-indent:2em" | 1335(10) keV
| 5(1) µs
|
|
| (8+)
|
|
|-
| 213Pb
|
| style="text-align:right" | 82
| style="text-align:right" | 131
| 212.996581(8)
| 10.2(3) min
| β-
| 213Bi
| (9/2+)
|
|
|-
| 214Pb
| Radium B
| style="text-align:right" | 82
| style="text-align:right" | 132
| 213.9998054(26)
| 26.8(9) min
| β-
| 214Bi
| 0+
| Trace
|
|-
| 215Pb
|
| style="text-align:right" | 82
| style="text-align:right" | 133
| 215.00481(44)#
| 36(1) s
|
|
| 5/2+#
|
|
|}
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