Rhenium-199

Properties and data of the isotope ¹⁹⁹Re.

Content

General data

Name of the isotope:Rhenium-199; Re-199Symbol:¹⁹⁹Re or 19975ReMass number A:199 (= number of nucleons)Atomic number Z:75 (= number of protons)Neutrons N:124Isotopic mass:198.98405(43) u (atomic weight of Rhenium-199)Nuclide mass:198.9429107 u (calculated nuclear mass without electrons)Mass excess:-14.85733 MeVMass defect:1.677276984 u (per nucleus)Nuclear binding energy:1562.37344693 MeV (per nucleus)
7.85112285 MeV (average binding energy per nucleon)Separation energy:S_N = 5.79(57) MeV (first neutron)Half-life:160 nsDecay constant λ:4332169.8784997 s^-1Specific activity α:1.31762309280 × 10⁺²⁸ Bq g^-1
3.561143494062 × 10⁺¹⁷ Ci g^-1Spin and parity:
(nuclear angular momentum)Year of discovery:2012

Radioactive Decay

Half-life T_½ = 160 ns respectively 1.6 × 10^-7 seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
β^-	¹⁹⁹Os	?	5.62(45) MeV
β^-, n	¹⁹⁸Os	?	0.90(45) MeV

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 124) and isobaric (same nucleon number A = 199) with Rhenium-199. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 124	Isobar A = 199
75	¹⁹⁹Re	¹⁹⁹Re
76	²⁰⁰Os	¹⁹⁹Os
77	²⁰¹Ir	¹⁹⁹Ir
78	²⁰²Pt	¹⁹⁹Pt
79	²⁰³Au	¹⁹⁹Au
80	²⁰⁴Hg	¹⁹⁹Hg
81	²⁰⁵Tl	¹⁹⁹Tl
82	²⁰⁶Pb	¹⁹⁹Pb
83	²⁰⁷Bi	¹⁹⁹Bi
84	²⁰⁸Po	¹⁹⁹Po
85	²⁰⁹At	¹⁹⁹At
86	²¹⁰Rn	¹⁹⁹Rn
87	²¹¹Fr	¹⁹⁹Fr
88	²¹²Ra
89	²¹³Ac
90	²¹⁴Th
91	²¹⁵Pa
92	²¹⁶U