H Home Background Color: He Li Be Fermium Main Page Black White Gray B C N O F Ne Na Mg Fermium Pictures Page Al Si P S Cl Ar K Ca Fermium Technical Data Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe Cs Ba La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn Fr Ra Ac Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr Rf Db Sg Bh Hs Mt Ds Rg Cn Nh Fl Mc Lv Ts Og

Isotopes of Fermium (click to see decay chain): 242Fm  243Fm  244Fm  245Fm  246Fm  247Fm  248Fm  249Fm  250Fm  251Fm  252Fm  253Fm  254Fm  255Fm  256Fm  257Fm  258Fm  259Fm  260Fm

257Fm     Half-life Fermion, 100p 157n 100.4976851852 d Spin 9/2 Parity 1 Hide Decay Modes Probability Mode Decay Energy Daughter 100% α 6.86355MeV 253Cf 0.21% SF N/A Variable Show Ultimate Decay Products Atomic Weight 257.095104724 Abundance None Mass Excess 88.589481MeV Binding Energy 7.422196MeV Magnetic Moment N/A Quadrupole Moment N/A   Show Element Pictures. Also show decay chains leading to this isotope. Show only decays with probability >0.1%. Show Decay Image Smaller.

Click any isotope in diagram to see its data. Decay chain image generated by Mathematica's GraphPlot and IsotopeData functions from Wolfram Research, Inc..