61-Pm-129  basic  element

61-promethium-129 Atomic Mass: 128.9431600 +- 0.0008600 amu # Excess Mass: -52946.000 +- 801.000 keV # Binding Energy: 1046423.000 +- 801.000 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.