Input interpretation
Fm-252 (fermium-252)
Decay properties
half-life | 25.4 hours (25.347 to 25.433 h) mean lifetime | 36.64 hours (36.572 to 36.6892 h) decay constant | 7.582×10^-6 per second specific activity | 18110 TBq/g (terabecquerels per gram) width | 4.991×10^-21 eV (electronvolts) decay modes | α (alpha emission) | SF (spontaneous fission) | 2β^+ (double beta decay) final decay products | Pb-208 (100%) | Pb-206 (4×10^-9%) | Pb-204 (0%) | Hg-200 (0%) | Hg-204 (0%)
Decay modes
decay mode | α (alpha emission) branching ratio | 100% Q-value | 7.1527 MeV (megaelectronvolts) daughter nuclide | Cf-248 decay mode | SF (spontaneous fission) branching ratio | 0.0023% decay mode | 2β^+ (double beta decay) Q-value | -1.26101 MeV (megaelectronvolts) daughter nuclide | Cf-252
Radiation shielding
lead | 23.9 µm water | 65.5 µm air | 59.6 mm
Decay chain
Decay chain
Mass properties
atomic number (Z) | 100 mass number (A) | 252 neutron number | 152 atomic mass | 252.082466855 u (unified atomic mass units) mass excess | 76.817382 MeV (megaelectronvolts) binding energy per nucleon | 7.456031 MeV (megaelectronvolts)
Mass properties
Nearby isotopes
Nearby isotopes
Quantum properties
spin parity J^π | 0^+ (atomic boson) magnetic moment | 0 μ_N
Quantum properties
Excitations
E_level | spin parity J^π | half-life τ_1/2 | width Δ 46.6 keV (kiloelectronvolts) | 2^+ | (unknown) | (unknown)