element
Information about Mendelevium-257:

WikipediaNeutron Cross SectionsX-Ray TransitionsX-Ray Attenuation

    Mass-Energy Data:

    Atomic Mass:257.095535±0.000004amu
    Excess Mass (Δ):88.989933±0.003298MeV
    Binding Energy:1906.322335±0.003316MeV
    β- Decay Energy:-1.227835±0.030793MeV
"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.
Radioactive Decay Data:

  • Spin: (7/2-)
  • Half life: 5.3 h ( 19080 sec., λ = 3.63285×10-05 s-1)
  • Mode of decay:
    E.C.
    to
    257
    100
    Fm
      (Q = 0.406 MeV)   Branch ratio: 90.00 %
  • Mode of decay:
    α
    to
    253
    99
    Es
      (Q = 7.558 MeV)   Branch ratio: 10.00 %
  • Mode of decay: SF   Branch ratio: <4.00 %
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)