Rhenium-191

Properties and data of the isotope ¹⁹¹Re.

Content

General data

Name of the isotope:Rhenium-191; Re-191Symbol:¹⁹¹Re or 19175ReMass number A:191 (= number of nucleons)Atomic number Z:75 (= number of protons)Neutrons N:116Isotopic mass:190.963123(11) u (atomic weight of Rhenium-191)Nuclide mass:190.9219837 u (calculated nuclear mass without electrons)Mass excess:-34.3507 MeVMass defect:1.628884656 u (per nucleus)Nuclear binding energy:1517.29628376 MeV (per nucleus)
7.9439596 MeV (average binding energy per nucleon)Separation energy:S_N = 6.79(7) MeV (first neutron)
S_P = 7.26(4) MeV (first proton)Half-life:9.8(5) minDecay constant λ:0.0011788217356462 s^-1Specific activity α:3.736331863587 × 10⁺¹⁸ Bq g^-1
100981942.25912 Ci g^-1Spin and parity:
(nuclear angular momentum)(3/2+.1/2+)Year of discovery:1963

Radioactive Decay

Half-life T_½ = 9.8(5) min (minutes) respectively 5.88 × 10² seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
β^-	¹⁹¹Os	100 %	2.045(10) MeV

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 116) and isobaric (same nucleon number A = 191) with Rhenium-191. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 116	Isobar A = 191
71	¹⁸⁷Lu
72	¹⁸⁸Hf
73	¹⁸⁹Ta	¹⁹¹Ta
74	¹⁹⁰W	¹⁹¹W
75	¹⁹¹Re	¹⁹¹Re
76	¹⁹²Os	¹⁹¹Os
77	¹⁹³Ir	¹⁹¹Ir
78	¹⁹⁴Pt	¹⁹¹Pt
79	¹⁹⁵Au	¹⁹¹Au
80	¹⁹⁶Hg	¹⁹¹Hg
81	¹⁹⁷Tl	¹⁹¹Tl
82	¹⁹⁸Pb	¹⁹¹Pb
83	¹⁹⁹Bi	¹⁹¹Bi
84	²⁰⁰Po	¹⁹¹Po
85	²⁰¹At	¹⁹¹At
86	²⁰²Rn
87	²⁰³Fr
88	²⁰⁴Ra
89	²⁰⁵Ac