Input interpretation
Am-243 (americium-243)
Decay properties
half-life | 7390 years (7326 to 7425 yr) mean lifetime | 10700 years (10570 to 10710 yr) decay constant | 2.98×10^-12 per second specific activity | 7.37 GBq/g (gigabecquerels per gram) width | 1.96×10^-27 eV (electronvolts) decay modes | α (alpha emission) | SF (spontaneous fission) final decay products | Pb-207 (100%) | Tl-205 (9×10^-10) | Pb-206 (8×10^-12) | Pb-208 (1×10^-14)
Critical properties
critical mass | 230 kg (kilograms) critical diameter | 32.5 cm (centimeters) (for a uniform sphere)
Decay modes
decay mode | α (alpha emission) branching ratio | 100% Q-value | 5.43881 MeV (megaelectronvolts) daughter nuclide | Np-239 decay mode | SF (spontaneous fission) branching ratio | 3.7×10^-11
Radiation shielding
lead | 16.7 µm water | 42.7 µm air | 38.9 mm
Decay chain
Decay chain
Mass properties
atomic number (Z) | 95 mass number (A) | 243 neutron number | 148 atomic mass | 243.06138108 u (unified atomic mass units) mass excess | 57.176109 MeV (megaelectronvolts) binding energy per nucleon | 7.530169 MeV (megaelectronvolts)
Mass properties
Nearby isotopes
Nearby isotopes
Quantum properties
spin parity J^π | 5/2^- (atomic boson) magnetic moment | 1.53 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 42.2 keV (kiloelectronvolts) | 7/2^- | 4×10^-11 seconds | 1.1×10^-5 eV (electronvolts) 84 keV (kiloelectronvolts) | 5/2^+ | 2.34×10^-9 seconds | 1.95×10^-7 eV (electronvolts) 96.4 keV (kiloelectronvolts) | 9/2^- | (unknown) | (unknown) 109.2 keV (kiloelectronvolts) | 7/2^+ | (unknown) | (unknown) 143.5 keV (kiloelectronvolts) | 9/2^+ | (unknown) | (unknown) 162.3 keV (kiloelectronvolts) | 11/2^- | (unknown) | (unknown) 189.3 keV (kiloelectronvolts) | 11/2^+ | (unknown) | (unknown) 238 keV (kiloelectronvolts) | 13/2^- | (unknown) | (unknown) 244 keV (kiloelectronvolts) | 13/2^+ | (unknown) | (unknown) 266 keV (kiloelectronvolts) | 3/2^- | (unknown) | (unknown)