Input interpretation
He-8 (helium-8)
Decay properties
half-life | 119 ms (milliseconds) (117.4 to 120.6 ms) mean lifetime | 172 ms (milliseconds) (169.4 to 174 ms) decay constant | 5.81 per second specific activity | 4.36×10^11 TBq/g (terabecquerels per gram) width | 3.83×10^-15 eV (electronvolts) decay modes | β^- (electron emission) | β^-n (electron + delayed neutron) | β^-t (electron + delayed triton) final decay products | He-4 (84%) | Li-7 (16%)
Decay modes
decay mode | β^- (electron emission) branching ratio | 83% Q-value | 10.6512 MeV (megaelectronvolts) daughter nuclide | Li-8 decay mode | β^-n (electron + delayed neutron) branching ratio | 16% Q-value | 8.61859 MeV (megaelectronvolts) daughter nuclide | Li-7 decay mode | β^-t (electron + delayed triton) branching ratio | 0.9% daughter nuclide | He-5
Decay chain
Decay chain
Mass properties
atomic number (Z) | 2 mass number (A) | 8 neutron number | 6 atomic mass | 8.033921897 u (unified atomic mass units) mass excess | 31.598044 MeV (megaelectronvolts) binding energy per nucleon | 3.925975 MeV (megaelectronvolts)
Mass properties
Nearby isotopes
Nearby isotopes
Quantum properties
spin parity J^π | 0^+ (atomic boson) magnetic moment | 0 μ_N
Quantum properties
Excitations
E_level | spin parity J^π | half-life τ_1/2 | width Δ 3100 keV (kiloelectronvolts) | 2^+ | 8×10^-22 seconds | 600 keV (kiloelectronvolts) 4360 keV (kiloelectronvolts) | 1^- | 3.5×10^-22 seconds | 1.3 MeV (megaelectronvolts) 6030 keV (kiloelectronvolts) | (unknown) | 3×10^-21 seconds | 150 keV (kiloelectronvolts) 7160 keV (kiloelectronvolts) | 3^- | 4.6×10^-21 seconds | 100 keV (kiloelectronvolts)