Input interpretation
Ac-209 | daughter nuclides
Result
Fr-205 | Ra-209
Decay properties
| Fr-205 | Ra-209 half-life | 3.8 s (3.73 to 3.87 s) | 4.6 s (4.34 to 4.86 s) mean lifetime | 5.48 s (5.35 to 5.62 s) | 6.6 s (6.31 to 6.96 s) decay constant | 0.182 per second | 0.15 per second specific activity | 5.36×10^8 TBq/g | 4.4×10^8 TBq/g width | 8.32×10^-17 eV | 9.9×10^-17 eV decay modes | α (alpha emission) | β^+ (positron emission) | α (alpha emission) | β^+ (positron emission) final decay products | Au-197 (70%) | Hg-201 (29%) | Tl-205 (0.7%) | Ir-193 (7×10^-5%) | Os-189 (7×10^-12%) | Tl-205 (70%) | Hg-201 (28%) | Au-197 (0.3%)
Decay modes
decay mode | α (alpha emission) branching ratio | 99% Q-value | 7.7292 MeV (megaelectronvolts) daughter nuclide | Fr-205 decay mode | β^+ (positron emission) branching ratio | 1% Q-value | 5.9673 MeV (megaelectronvolts) daughter nuclide | Ra-209
Fr-205
decay mode | α (alpha emission) branching ratio | 100% Q-value | 7.05486 MeV (megaelectronvolts) daughter nuclide | At-201 decay mode | β^+ (positron emission) branching ratio | 1% Q-value | 5.382 MeV (megaelectronvolts) daughter nuclide | Rn-205
Ra-209
decay mode | α (alpha emission) branching ratio | 90% Q-value | 7.14393 MeV (megaelectronvolts) daughter nuclide | Rn-205 decay mode | β^+ (positron emission) branching ratio | 10% Q-value | 4.602 MeV (megaelectronvolts) daughter nuclide | Fr-209
Radiation shielding
| Fr-205 lead | 23.5 µm water | 64.1 µm air | 58.4 mm
Decay chain
Fr-205
Decay chain Fr-205
Ra-209
Decay chain Ra-209
Mass properties
| Fr-205 | Ra-209 atomic number (Z) | 87 | 88 mass number (A) | 205 | 209 neutron number | 118 | 121 atomic mass | 204.99859396 u (unified atomic mass units) | 209.001991373 u (unified atomic mass units) mass excess | -1.309717 MeV (megaelectronvolts) | 1.854952 MeV (megaelectronvolts) binding energy per nucleon | 7.745686 MeV (megaelectronvolts) | 7.733033 MeV (megaelectronvolts)
Mass properties
Nearby isotopes
Nearby isotopes
Quantum properties
| Fr-205 | Ra-209 spin parity J^π | 9/2^- (atomic boson) | 5/2^- (atomic fermion) magnetic moment | (unknown) | 0.865 μ_N electric quadrupole moment | (unknown) | 0.38 eb (electron barns)
Quantum properties