Input interpretation
Ac-229 | daughter nuclides
Result
Th-229
Decay properties
half-life | 7880 years (7753 to 8007 yr) mean lifetime | 11370 years (11180 to 11560 yr) decay constant | 2.789×10^-12 per second specific activity | 7.334 GBq/g (gigabecquerels per gram) width | 1.272×10^-27 eV (electronvolts) decay modes | α (alpha emission) final decay products | Tl-205 (100%) | Pb-207 (7×10^-12)
Decay mode
decay mode | β^- (electron emission) Q-value | 1.167 MeV (megaelectronvolts) daughter nuclide | Th-229
decay mode | α (alpha emission) Q-value | 5.16757 MeV (megaelectronvolts) daughter nuclide | Ra-225
Radiation shielding
lead | 15.6 µm water | 39.5 µm air | 36 mm
Decay chain
Decay chain
Mass properties
atomic number (Z) | 90 mass number (A) | 229 neutron number | 139 atomic mass | 229.03176243 u (unified atomic mass units) mass excess | 29.586514 MeV (megaelectronvolts) binding energy per nucleon | 7.634646 MeV (megaelectronvolts)
Mass properties
Nearby isotopes
Nearby isotopes
Quantum properties
spin parity J^π | 5/2^+ (atomic fermion) magnetic moment | 0.46 μ_N electric quadrupole moment | 4.3 eb (electron barns)
Quantum properties
Excitations
E_level | spin parity J^π | half-life τ_1/2 | width Δ 0.01 keV (kiloelectronvolts) | 3/2^+ | (unknown) | (unknown) 21 keV (kiloelectronvolts) | (unknown) | (unknown) | (unknown) 29.19 keV (kiloelectronvolts) | 5/2^+ | (unknown) | (unknown) 42.44 keV (kiloelectronvolts) | 7/2^+ | 1.72×10^-10 seconds | 2.65×10^-6 eV (electronvolts) 68 keV (kiloelectronvolts) | (unknown) | (unknown) | (unknown) 71.82 keV (kiloelectronvolts) | 7/2^+ | (unknown) | (unknown) 75 keV (kiloelectronvolts) | (unknown) | (unknown) | (unknown) 97.13 keV (kiloelectronvolts) | 9/2^+ | 1.47×10^-10 seconds | 3.1×10^-6 eV (electronvolts) 125.41 keV (kiloelectronvolts) | 9/2^+ | (unknown) | (unknown) 140 keV (kiloelectronvolts) | (unknown) | (unknown) | (unknown)