Input interpretation
Fm-259 (fermium-259) | Md-257 (mendelevium-257)
Decay properties
| Fm-259 | Md-257 half-life | 1.5 s (1.18 to 1.82 s) | 5.53 h (5.4689 to 5.5728 h) mean lifetime | 2.2 s (1.71 to 2.62 s) | 7.97 h (7.85 to 8.0394 h) decay constant | 0.45 per second | 3.48×10^-5 per second specific activity | 1.1×10^9 TBq/g | 81600 TBq/g width | 3×10^-16 eV | 2.3×10^-20 eV decay modes | SF (spontaneous fission) | ϵ (electron capture) | α (alpha emission) | SF (spontaneous fission) final decay products | | Tl-205 (100%) | Pb-207 (7×10^-12)
Decay modes
Fm-259
decay mode | SF (spontaneous fission) branching ratio | 100%
Md-257
decay mode | ϵ (electron capture) branching ratio | 85% Q-value | 406.73 keV (kiloelectronvolts) daughter nuclide | Fm-257 decay mode | α (alpha emission) branching ratio | 15% Q-value | 7.5576 MeV (megaelectronvolts) daughter nuclide | Es-253 decay mode | SF (spontaneous fission) branching ratio | 4%
Radiation shielding
Radiation shielding
Decay chain
Md-257
Decay chain Md-257
Mass properties
| Fm-259 | Md-257 atomic number (Z) | 100 | 101 mass number (A) | 259 | 257 neutron number | 159 | 156 atomic mass | 259.100595 u (unified atomic mass units) | 257.095541368 u (unified atomic mass units) mass excess | 93.704 MeV (megaelectronvolts) | 88.996213 MeV (megaelectronvolts) binding energy per nucleon | 7.407 MeV (megaelectronvolts) | 7.417569 MeV (megaelectronvolts)
Mass properties
Nearby isotopes
Nearby isotopes
Quantum properties
| Fm-259 | Md-257 spin parity J^π | 3/2^+ (atomic fermion) | 7/2^- (atomic boson)
Quantum properties