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LEAD Pb Z = 82

This element has been known since antiquity. Lead in Latin is plumbum.

Ionization energies
PbI 7.4 eV, PbII 15.0 eV, PbIII 31.9 eV.

Absorption lines of PbI
In the sun the PbI line 3683(1) has W = 0.010. Fay et al. (1968) identified some lines of this element in M-type stars.

Emission lines of PbI
The 3683 line is seen as a sharp strong emission line in the solar chromosphere (Pierce 1968).

Behavior in non-normal stars
PbI was detected by Burbidge and Burbidge (1955) in one Ap star and confirmed by Guthrie (1972) and two Ap stars of the Cr-Eu-Sr subgroup.

PbII 2203(2) was found by Severny and Lyubimkov (1985) in one Ap star of the Cr-Eu-Sr type.

Sadakane (1991) identified the 2203 line in the spectrum of one Am star.

Warner (1965) found that Pb is enhanced in Ba stars.

Isotopes
Lead occurs in the form of four stable isotopes, namely Pb 204, 206, 207 and 208. They contribute respectively 1%, 24%, 22% and 52% of the existing Pb. There exist also two unstable isotopes of long half life, namely Pb202 (3 × 105 years) and Pb205 (3 × 107 years) and 23 short-lived isotopes and isomers. The longer lived isotopes can be used for radioactive dating.

Origin
Pb 206, 207 and 208 are produced by either the r process or the s process. Pb204 can only be produced by the s process.



Published in "The Behavior of Chemical Elements in Stars", Carlos Jaschek and Mercedes Jaschek, 1995, Cambridge University Press.

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