Input interpretation
Ac-229 (actinium-229)
Decay properties
half-life | 62.67 minutes (62.13 to 63.28 min) mean lifetime | 90.5 minutes (89.63 to 91.27 min) decay constant | 1.842×10^-4 per second specific activity | 484200 TBq/g (terabecquerels per gram) width | 1.21×10^-19 eV (electronvolts) decay modes | β^- (electron emission) final decay products | Tl-205 (100%) | Pb-207 (7×10^-10%)
Decay mode
decay mode | β^- (electron emission) Q-value | 1.167 MeV (megaelectronvolts) daughter nuclide | Th-229
Radiation shielding
lead | 822 µm portland concrete | 2.71 mm water | 5.27 mm air | 4.63 m
Decay chain
Decay chain
Mass properties
atomic number (Z) | 89 mass number (A) | 229 neutron number | 140 atomic mass | 229.033015243 u (unified atomic mass units) mass excess | 30.753502 MeV (megaelectronvolts) binding energy per nucleon | 7.632966 MeV (megaelectronvolts)
Mass properties
Nearby isotopes
Nearby isotopes
Quantum properties
spin parity J^π | 3/2^+ (atomic boson)
Quantum properties
Excitations
E_level | spin parity J^π | half-life τ_1/2 | width Δ 5 keV (kiloelectronvolts) | 5/2^+ | (unknown) | (unknown) 26 keV (kiloelectronvolts) | 9/2^+ | (unknown) | (unknown) 70 keV (kiloelectronvolts) | (unknown) | (unknown) | (unknown) 91 keV (kiloelectronvolts) | 13/2^+ | (unknown) | (unknown) 102 keV (kiloelectronvolts) | 3/2^- | (unknown) | (unknown) 120 keV (kiloelectronvolts) | (unknown) | (unknown) | (unknown) 151 keV (kiloelectronvolts) | 1/2^+ | (unknown) | (unknown) 165 keV (kiloelectronvolts) | 7/2^- | (unknown) | (unknown) 191 keV (kiloelectronvolts) | 3/2^+ | (unknown) | (unknown) 283 keV (kiloelectronvolts) | (unknown) | (unknown) | (unknown)