H Home Background Color: He Li Be Neptunium Main Page Black White Gray B C N O F Ne Na Mg Neptunium Pictures Page Al Si P S Cl Ar K Ca Neptunium 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 Uub Uut Uuq Uup Uuh Uus Uuo

Isotopes of Neptunium (click to see decay chain): 225Np  226Np  227Np  228Np  229Np  230Np  231Np  232Np  233Np  234Np  235Np  236Np  237Np  238Np  239Np  240Np  241Np  242Np  243Np  244Np

239Np     Half-life Boson, 93p 146n 2.3565d Spin 5/2 Parity 1 Hide Decay Modes Probability Mode Decay Energy Daughter 100.% β- 722.508keV 239Pu 5.×10-10% α 4557.keV 235Pa Hide Ultimate Decay Products Yield Nuclide 100.27631366700267% 207Pb Atomic Weight 239.052939025 Abundance None Mass Excess 49.312385MeV Binding Energy 7.560561MeV Magnetic Moment N/A Quadrupole Moment N/A   Show Element Pictures. Also show decay chains leading to this isotope. Show all decays, even very low-probability.

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