Rhenium-186m

Properties and data of the isotope ¹⁸⁶Re.

Content

General data

Name of the isotope:Rhenium-186m; Re-186mSymbol:¹⁸⁶Re or 18675ReMass number A:186 (= number of nucleons)Atomic number Z:75 (= number of protons)Neutrons N:111Isotopic mass:185.9549892(9) u (atomic weight of Rhenium-186m)
Excitation energy: 148.2(5) keVNuclide mass:185.9138499 u (calculated nuclear mass without electrons)Mass excess:-41.92729 MeVMass defect:1.593693876 u (per nucleus)Nuclear binding energy:1484.51628333 MeV (per nucleus)
7.98127034 MeV (average binding energy per nucleon)Half-life:200000 aDecay constant λ:1.098977645484 × 10^-13 s^-1Specific activity α:357740442.32589 Bq g^-1
0.0096686606034024 Ci g^-1Spin and parity:
(nuclear angular momentum)(8+)

Radioactive Decay

Half-life T_½ = 200000 a respectively 6.3072 × 10¹² seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
Iso	¹⁸⁶W	100 %

Nuclear Isomers

Nuclear isomers or excited states with the activation energy in keV related to the ground state.

Nuclear Isomer	Excitation Energy	Half-life	Spin
¹⁸⁶Re		3.7185(5) d	1-

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 111) and isobaric (same nucleon number A = 186) with Rhenium-186m. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 111	Isobar A = 186
70	¹⁸¹Yb
71	¹⁸²Lu	¹⁸⁶Lu
72	¹⁸³Hf	¹⁸⁶Hf
73	¹⁸⁴Ta	¹⁸⁶Ta
74	¹⁸⁵W	¹⁸⁶W
75	¹⁸⁶Re	¹⁸⁶Re
76	¹⁸⁷Os	¹⁸⁶Os
77	¹⁸⁸Ir	¹⁸⁶Ir
78	¹⁸⁹Pt	¹⁸⁶Pt
79	¹⁹⁰Au	¹⁸⁶Au
80	¹⁹¹Hg	¹⁸⁶Hg
81	¹⁹²Tl	¹⁸⁶Tl
82	¹⁹³Pb	¹⁸⁶Pb
83	¹⁹⁴Bi	¹⁸⁶Bi
84	¹⁹⁵Po	¹⁸⁶Po
85	¹⁹⁶At
86	¹⁹⁷Rn