This element was discovered by F. Stromeyer in 1817 in Göttingen, Germany. The name comes from the Latin cadmia (calomine, a zinc carbonate). The element was isolated from impurities in calamine.
Ionization energies
CdI 9.0 eV, CdII 16.9 eV, CdIII 37.4 eV.
Absorption lures of CdI
The equivalent width of the CdI line 5085(2) in the sun is 0.0007.
Behavior in non-normal stars
Jaschek and Brandi (1972) detected CdI and CdII in one Ap star of the Cr-Eu-Sr subgroup.
CdII was detected in two Am stars by Boyartchuk and Snow (1978) with W(2265) = 0.018. Sadakane (1991) found two CdII lines (2144 and 2265, both of M.1) in the spectrum of another Am star.
Isotopes
Cd has eight stable isotopes - Cd 106, 108, 110, 111, 112, 113, 114 and 116, as well as 14 short-lived isotopes and isomers. In the solar system one finds respectively Cd 106 (1%), 108 (1%), 110 (12%), 111 (13%), 112 (24%), 113 (12%), 114 (29%) and 116 (7%).
Origin
Cd is produced by several processes: Cd106 and Cd108 by the p, Cd110 by the s, Cd116 by the r and Cd 111, 112, 113 and 114 by either the r or the s process.
Published in "The Behavior of Chemical Elements in Stars", Carlos Jaschek and Mercedes Jaschek, 1995, Cambridge University Press.