See also: List of individual Hafnium isotopes (and general data sources).
General data
Name of the isotope:Hafnium-161; Hf-161Symbol:161Hf or 16172HfMass number A:161 (= number of nucleons)Atomic number Z:72 (= number of protons)Neutrons N:89Nucleon pairing (Z - N):even - oddNuclear ratio (N/Z ratio):1.2361111111111 (= neutron-proton ratio)Neutron excess (N-Z):17Isotopic mass:160.950279(24) u (atomic weight of Hafnium-161)Nuclide mass:160.910785 u (calculated nuclear mass without electrons)Mass excess:-46.31481 MeVMass defect:1.384300828 u (per nucleus)Nuclear binding energy:1289.46791548 MeV (per nucleus) 8.00911749 MeV (average binding energy per nucleon)Separation energy:SN = 8.447(24) MeV (first neutron) SP = 3.33(6) MeV (first proton)Half-life:18.4(4)sDecay constant λ:0.037671042421736 s-1Specific activity α:1.40950560290 × 10+20 Bq g-1 3809474602.4459 Ci g-1Spin and parity: (nuclear angular momentum)(7/2-)Year of discovery:1973
Radioactive Decay
Half-life T½ = 18.4(4)s respectively 1.84 × 101 seconds s.
The following table shows the atomic nuclei that are isotonic (same neutron number N = 89) and isobaric (same nucleon number A = 161) with Hafnium-161. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.
