Input interpretation
Ac-231 | daughter nuclides
Result
Th-231
Decay properties
half-life | 25.519 hours (25.507 to 25.533 h) mean lifetime | 36.81 hours (36.8025 to 36.85 h) decay constant | 7.547×10^-6 per second specific activity | 19670 TBq/g (terabecquerels per gram) width | 4.966×10^-21 eV (electronvolts) decay modes | β^- (electron emission) | α (alpha emission) final decay products | Pb-207 (100%) | Tl-205 (9×10^-10) | Pb-208 (1×10^-14)
Decay mode
decay mode | β^- (electron emission) Q-value | 2.1 MeV (megaelectronvolts) daughter nuclide | Th-231
Decay modes
decay mode | β^- (electron emission) branching ratio | 100% Q-value | 391.56 keV (kiloelectronvolts) daughter nuclide | Pa-231 decay mode | α (alpha emission) branching ratio | 4×10^-13 Q-value | 4.21338 MeV (megaelectronvolts) daughter nuclide | Ra-227
Radiation shielding
lead | 214 µm portland concrete | 647 µm water | 1.25 mm air | 111 cm
Decay chain
Decay chain
Mass properties
atomic number (Z) | 90 mass number (A) | 231 neutron number | 141 atomic mass | 231.036304343 u (unified atomic mass units) mass excess | 33.817278 MeV (megaelectronvolts) binding energy per nucleon | 7.620112 MeV (megaelectronvolts)
Mass properties
Nearby isotopes
Nearby isotopes
Quantum properties
spin parity J^π | 5/2^+ (atomic fermion)
Quantum properties
Excitations
E_level | spin parity J^π | half-life τ_1/2 | width Δ 41.952 keV (kiloelectronvolts) | 7/2^+ | (unknown) | (unknown) 96.129 keV (kiloelectronvolts) | 9/2^+ | (unknown) | (unknown) 161.94 keV (kiloelectronvolts) | 11/2^+ | (unknown) | (unknown) 185.714 keV (kiloelectronvolts) | 5/2^- | 7.7×10^-10 seconds | 5.9×10^-7 eV (electronvolts) 205.309 keV (kiloelectronvolts) | 7/2^- | (unknown) | (unknown) 221.398 keV (kiloelectronvolts) | 3/2^+ | (unknown) | (unknown) 236.893 keV (kiloelectronvolts) | 9/2^- | (unknown) | (unknown) 240.881 keV (kiloelectronvolts) | 5/2^+ | (unknown) | (unknown) 247.583 keV (kiloelectronvolts) | 1/2^+ | (unknown) | (unknown) 272.18 keV (kiloelectronvolts) | 3/2^+ | (unknown) | (unknown)