Isotopes of lead

  • main isotopes of lead (82pb)
    iso­tope decay
    abun­dance half-life (t1/2) mode pro­duct
    202pb syn 5.25(28)×104 y ε 202tl
    204pb 1.4% stable
    205pb trace 1.73(7)×107 y ε 205tl
    206pb 24.1% stable
    207pb 22.1% stable
    208pb 52.4% stable
    209pb trace 3.253(14) h β 209bi
    210pb trace 22.3(22) y β 210bi
    211pb trace 36.1(2) min β 211bi
    212pb trace 10.64(1) h β 212bi
    214pb trace 26.8(9) min β 214bi
    isotopic abundances vary greatly by sample
    standard atomic weight ar, standard(pb)
    • 207.2(1)[1]

    lead (82pb) 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; 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, 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 17.3 million years and 202pb with a half-life of 52,500 years. a shorter-lived naturally occurring radioisotope, 210pb with a half-life of 22.3 years, is useful for studying the sedimentation chronology of environmental samples on time scales shorter than 100 years.[2]

    the relative abundances of the four stable isotopes are approximately 1.5%, 24%, 22%, and 52.5%, combining to give a standard atomic weight (abundance-weighted average of the stable isotopes) of 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 2.01×1019 years.) a total of 43 lead isotopes are now known, including very unstable synthetic species.

    in its fully ionized state, the isotope 205pb also becomes stable.[3]

  • list of isotopes
  • lead-206
  • lead-204, -207, and -208
  • references

Main isotopes of lead (82Pb)
Iso­tope Decay
abun­dance half-life (t1/2) mode pro­duct
202Pb syn 5.25(28)×104 y ε 202Tl
204Pb 1.4% stable
205Pb trace 1.73(7)×107 y ε 205Tl
206Pb 24.1% stable
207Pb 22.1% stable
208Pb 52.4% stable
209Pb trace 3.253(14) h β 209Bi
210Pb trace 22.3(22) y β 210Bi
211Pb trace 36.1(2) min β 211Bi
212Pb trace 10.64(1) h β 212Bi
214Pb trace 26.8(9) min β 214Bi
Isotopic abundances vary greatly by sample
Standard atomic weight Ar, standard(Pb)

Lead (82Pb) 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; 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, 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 17.3 million years and 202Pb with a half-life of 52,500 years. A shorter-lived naturally occurring radioisotope, 210Pb with a half-life of 22.3 years, is useful for studying the sedimentation chronology of environmental samples on time scales shorter than 100 years.[2]

The relative abundances of the four stable isotopes are approximately 1.5%, 24%, 22%, and 52.5%, combining to give a standard atomic weight (abundance-weighted average of the stable isotopes) of 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 2.01×1019 years.) A total of 43 lead isotopes are now known, including very unstable synthetic species.

In its fully ionized state, the isotope 205Pb also becomes stable.[3]