Input interpretation
Pu-238 (plutonium-238)
Decay properties
half-life | 87.8 years (87.51 to 88 yr) mean lifetime | 127 years (126.4 to 126.9 yr) decay constant | 2.51×10^-10 per second specific activity | 634 GBq/g (gigabecquerels per gram) width | 1.65×10^-25 eV (electronvolts) decay modes | α (alpha emission) | SF (spontaneous fission) | ^32Si (cluster emission) | ^28Mg +^30Mg (double cluster emission) final decay products | Pb-206 (100%) | Tl-205 (1.9×10^-8) | Pb-208 (2.6×10^-11) | W-184 (9×10^-14) | Yb-168 (2×10^-17) | Er-164 (2×10^-17) | Dy-160 (8×10^-19) | Dy-156 (5×10^-21) | Sm-144 (5×10^-22) | Ce-140 (5×10^-23) | Dy-164 (0) | Er-168 (0) | Gd-156 (0) | Hf-176 (0) | Hf-180 (0) | Sm-152 (0) | Yb-172 (0)
Critical properties
critical mass | 9.55 kg (kilograms) critical diameter | 9.7 cm (centimeters) (for a uniform sphere)
Decay modes
decay mode | α (alpha emission) branching ratio | 100% Q-value | 5.5932 MeV (megaelectronvolts) daughter nuclide | U-234 decay mode | SF (spontaneous fission) branching ratio | 1.9×10^-9 decay mode | ^32Si (cluster emission) branching ratio | 1.4×10^-16 daughter nuclide | Hg-206 decay mode | ^28Mg +^30Mg (double cluster emission) branching ratio | 6×10^-17 daughter nuclide | Pb-180
Radiation shielding
lead | 17.3 µm water | 44.6 µm air | 40.6 mm
Decay chain
Decay chain
Mass properties
atomic number (Z) | 94 mass number (A) | 238 neutron number | 144 atomic mass | 238.049559894 u (unified atomic mass units) mass excess | 46.164745 MeV (megaelectronvolts) binding energy per nucleon | 7.568354 MeV (megaelectronvolts)
Mass properties
Nearby isotopes
Nearby isotopes
Quantum properties
spin parity J^π | 0^+ (atomic boson) magnetic moment | 0 μ_N
Quantum properties