Input interpretation
Am-239 (americium-239)
Decay properties
half-life | 11.9 hours (11.796 to 12.004 h) mean lifetime | 17.2 hours (17.018 to 17.318 h) decay constant | 1.62×10^-5 per second specific activity | 40800 TBq/g (terabecquerels per gram) width | 1.06×10^-20 eV (electronvolts) decay modes | ϵ (electron capture) | α (alpha emission) final decay products | Pb-207 (100%) | Tl-205 (9×10^-10) | Pb-206 (8×10^-12) | Pb-208 (1×10^-14)
Decay modes
decay mode | ϵ (electron capture) branching ratio | 100% Q-value | 802.11 keV (kiloelectronvolts) daughter nuclide | Pu-239 decay mode | α (alpha emission) branching ratio | 1×10^-4 Q-value | 5.9224 MeV (megaelectronvolts) daughter nuclide | Np-235
Decay chain
Decay chain
Mass properties
atomic number (Z) | 95 mass number (A) | 239 neutron number | 144 atomic mass | 239.053024479 u (unified atomic mass units) mass excess | 49.391985 MeV (megaelectronvolts) binding energy per nucleon | 7.553681 MeV (megaelectronvolts)
Mass properties
Nearby isotopes
Nearby isotopes
Quantum properties
spin parity J^π | 5/2^- (atomic boson)
Quantum properties
Excitations
E_level | spin parity J^π | half-life τ_1/2 | width Δ 40.7 keV (kiloelectronvolts) | 7/2^- | (unknown) | (unknown) 94 keV (kiloelectronvolts) | 9/2^- | (unknown) | (unknown) 156 keV (kiloelectronvolts) | 11/2^- | (unknown) | (unknown) 187.1 keV (kiloelectronvolts) | 5/2^+ | (unknown) | (unknown) 220 keV (kiloelectronvolts) | 7/2^+ | (unknown) | (unknown) 260 keV (kiloelectronvolts) | 9/2^+ | (unknown) | (unknown) 317 keV (kiloelectronvolts) | 11/2^+ | (unknown) | (unknown) 370 keV (kiloelectronvolts) | 13/2^+ | (unknown) | (unknown) 557 keV (kiloelectronvolts) | 3/2^- | (unknown) | (unknown) 586 keV (kiloelectronvolts) | 5/2^- | (unknown) | (unknown) 2500 keV (kiloelectronvolts) | 7/2^+ | 1.63×10^-7 seconds | 2.8×10^-9 eV (electronvolts)