Input interpretation
Ac-211 (actinium-211)
Decay properties
half-life | 210 ms (milliseconds) (160 to 260 ms) mean lifetime | 303 ms (milliseconds) (210 to 400 ms) decay constant | 3.3 per second specific activity | 9.42×10^9 TBq/g (terabecquerels per gram) width | 1.51×10^-15 eV (electronvolts) decay modes | α (alpha emission) | β^+ (positron emission) final decay products | Tl-203 (70%) | Hg-199 (29%) | Pb-207 (3.8%)
Decay modes
decay mode | α (alpha emission) branching ratio | 100% Q-value | 7.6216 MeV (megaelectronvolts) daughter nuclide | Fr-207 decay mode | β^+ (positron emission) branching ratio | 0.2% Q-value | 5.3463 MeV (megaelectronvolts) daughter nuclide | Ra-211
Radiation shielding
lead | 26.1 µm water | 72.5 µm air | 66 mm
Decay chain
Decay chain
Mass properties
atomic number (Z) | 89 mass number (A) | 211 neutron number | 122 atomic mass | 211.007734835 u (unified atomic mass units) mass excess | 7.204953 MeV (megaelectronvolts) binding energy per nucleon | 7.707176 MeV (megaelectronvolts)
Mass properties
Nearby isotopes
Nearby isotopes
Quantum properties
spin parity J^π | 9/2^- (atomic boson)
Quantum properties