See also: List of individual Promethium isotopes (and general data sources).
General data
Name of the isotope:Promethium-145; Pm-145Symbol:145Pm or 14561PmMass number A:145 (= number of nucleons)Atomic number Z:61 (= number of protons)Neutrons N:84Nucleon pairing (Z - N):odd - evenNuclear ratio (N/Z ratio):1.3770491803279 (= neutron-proton ratio)Neutron excess (N-Z):23Isotopic mass:144.912756(3) u (atomic weight of Promethium-145)Nuclide mass:144.8792952 u (calculated nuclear mass without electrons)Mass excess:-81.26726 MeVMass defect:1.292423896 u (per nucleus)Nuclear binding energy:1203.88510458 MeV (per nucleus) 8.30265589 MeV (average binding energy per nucleon)Separation energy:SN = 7.9227(15) MeV (first neutron) SP = 4.8085(25) MeV (first proton)Half-life:17.7(4) yearsDecay constant λ:1.241776421218 × 10-9 s-1Specific activity α:5160451438123.7 Bq g-1 139.47166048983 Ci g-1Spin and parity: (nuclear angular momentum)5/2+Magnetic dipole moment:μ(μN) = 3.8Quadrupole moment Q:+0.23(8) barn (100 fm2)Nuclear g-factor:gl = 1.52Year of discovery:1951
Radioactive Decay
Half-life T½ = 17.7(4) years respectively 5.5819 × 108 seconds s.
The following table shows the atomic nuclei that are isotonic (same neutron number N = 84) and isobaric (same nucleon number A = 145) with Promethium-145. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.
