Rhenium-186

Properties and data of the isotope ¹⁸⁶Re.

Contents

General data

Name of the isotope:Rhenium-186; Re-186Symbol: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-186)Nuclide 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)Separation energy:S_N = 6.17959(5) MeV (first neutron)
S_P = 5.8284(7) MeV (first proton)Half-life:3.7185(5) dDecay constant λ:2.157465863126 × 10^-6 s^-1Specific activity α:7.023007204461 × 10⁺¹⁵ Bq g^-1
189811.00552598 Ci g^-1Spin and parity:
(nuclear angular momentum)1-Magnetic dipole moment:μ(μ_N) = + 1.734(3)Quadrupole moment Q:+0.618(6) barn (100 fm²)Nuclear g-factor:g_l = 1.734Year of discovery:1939

Radioactive Decay

Half-life T_½ = 3.7185(5) d respectively 3.212784 × 10⁵ seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
EC	¹⁸⁶W	7.50(10) %	0.5813(15) MeV	0.13715(5) MeV 9.47(3) %
β^-	¹⁸⁶Os	92.50(10) %	1.0727(8) MeV

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
^186mRe	148.2(5) keV	200000 a	(8+)

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-186. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	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