See also: List of individual Radium isotopes (and general data sources).
General data
Name of the isotope:Radium-227; Ra-227Symbol:227Ra or 22788RaMass number A:227 (= number of nucleons)Atomic number Z:88 (= number of protons)Neutrons N:139Nucleon pairing (Z - N):even - oddNuclear ratio (N/Z ratio):1.5795454545455 (= neutron-proton ratio)Neutron excess (N-Z):51Isotopic mass:227.0291765(21) u (atomic weight of Radium-227)Nuclide mass:226.9809075 u (calculated nuclear mass without electrons)Mass excess:27.17773 MeVMass defect:1.86384964 u (per nucleus)Nuclear binding energy:1736.16475656 MeV (per nucleus) 7.64830289 MeV (average binding energy per nucleon)Separation energy:SN = 4.56143(27) MeV (first neutron) SP = 7.632(7) MeV (first proton)Half-life:42.2(5) minDecay constant λ:0.00027375481064769 s-1Specific activity α:7.261577691744 × 10+17 Bq g-1 19625885.653364 Ci g-1Spin and parity: (nuclear angular momentum)3/2+Magnetic dipole moment:μ(μN) = - 0.4038(24)Quadrupole moment Q:+1.53(6) barn (100 fm2)Nuclear g-factor:gl = -0.2692Charge radius:5.7283(300) femtometer fmYear of discovery:1953
Radioactive Decay
Half-life T½ = 42.2(5) min (minutes) respectively 2.532 × 103 seconds s.
The following table shows the atomic nuclei that are isotonic (same neutron number N = 139) and isobaric (same nucleon number A = 227) with Radium-227. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.
