Bi-209 has been known as stable nuclide. But,
alpha decay of Bi-209 with a half time of 2*1019 years
was found, recently.
Reference :
PIERRE DE MARCILLAC, NOEL CORON, GERARD DAMBIER, JACQUES LEBLANC &
JEAN-PIERRE MOALIC, "
Experimental detection of a-particles from the radioactive decay
of natural bismuth,"
Nature 422, 876-878 (2003); doi:10.1038/nature01541
contributed by :
Atomic Mass: 208.9803832 +- 0.0000032 amu
Excess Mass: -18272.891 +- 2.992 keV
Binding Energy: 1640244.025 +- 3.005 keV
Beta Decay Energy: B- -1893.305 +- 1.599 keV
"The 1995 update to the atomic mass evaluation" by G.Audi and A.H.Wapstra,
Nuclear Physics A595 vol. 4 p.409-480, December 25, 1995.
R.R.Kinsey, et al.,The NUDAT/PCNUDAT Program for Nuclear Data,paper submitted to the 9 th International Symposium of Capture-Gamma_raySpectroscopy and Related Topics, Budapest, Hungary, Octover 1996.Data extracted from NUDAT database (Jan. 14/1999)
Magnetic Dipole Moments and Electric Quadrupole Moments