See also: List of individual Osmium isotopes (and general data sources).
General data
Name of the isotope:Osmium-189; Os-189Symbol:189Os or 18976OsMass number A:189 (= number of nucleons)Atomic number Z:76 (= number of protons)Neutrons N:113Nucleon pairing (Z - N):even - oddNuclear ratio (N/Z ratio):1.4868421052632 (= neutron-proton ratio)Neutron excess (N-Z):37Isotopic mass:188.95814(2) u (atomic weight of Osmium-189)Nuclide mass:188.9164522 u (calculated nuclear mass without electrons)Mass excess:-38.99234 MeVMass defect:1.61569794 u (per nucleus)Nuclear binding energy:1505.01293692 MeV (per nucleus) 7.96303141 MeV (average binding energy per nucleon)Separation energy:SN = 5.9208(4) MeV (first neutron) SP = 7.2589(5) MeV (first proton)Half-life:stableSpin and parity: (nuclear angular momentum)3/2-Magnetic dipole moment:μ(μN) = + 0.659933(4)Charge radius:5..4016(11) femtometer fmYear of discovery:1931
The following table shows the atomic nuclei that are isotonic (same neutron number N = 113) and isobaric (same nucleon number A = 189) with Osmium-189. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.