Rhenium-187

Properties and data of the isotope ¹⁸⁷Re.

Contents

General Data

Radioactive Decay

Parent Nuclides

NMR Data

Isotones und Isobares

See also: List of individual Rhenium isotopes (and general data sources).

General data

Name of the isotope:Rhenium-187; Re-187Symbol:¹⁸⁷Re or 18775ReMass number A:187 (= number of nucleons)Atomic number Z:75 (= number of protons)Neutrons N:112Nucleon pairing (Z - N):odd - evenNuclear ratio (N/Z ratio):1.4933333333333 (= neutron-proton ratio)Neutron excess (N-Z):37Isotopic mass:186.95575(1) u (atomic weight of Rhenium-187)Nuclide mass:186.9146107 u (calculated nuclear mass without electrons)Mass excess:-41.21861 MeVMass defect:1.601597992 u (per nucleus)Nuclear binding energy:1491.87891996 MeV (per nucleus)
7.97796214 MeV (average binding energy per nucleon)Separation energy:S_N = 7.3605(9) MeV (first neutron)
S_P = 5.9969(11) MeV (first proton)Half-life:4.33(7) × 10¹⁰ aDecay constant λ:5.076109217018 × 10^-19 s^-1Specific activity α:1643.4970282423 Bq g^-1
4.441883860114 × 10^-8 Ci g^-1Spin and parity:
(nuclear angular momentum)5/2+Magnetic dipole moment:μ(μ_N) = + 3.2197(3)Charge radius:5.3698(173) femtometer fmYear of discovery:1931

Radioactive Decay

Half-life T_½ = 4.33(7) × 10¹⁰ a respectively 1.3655088 × 10¹⁸ seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
β^-	¹⁸⁷Os	> 99.999 %	2.467(2) MeV
α	¹⁸³Ta	< 0.0001 %	1.6521(17) MeV

Parent Nuclides

Direct parent isotope is: ¹⁸⁷W.

Occurrence

Comparison of the natural Rhenium isotopes including isotopic abundance (mole fraction of the isotope mixture in percent):

	Atomic Mass m_a	Quantity	Half-life	Spin
Rhenium Isotopic mixture	186.207 u	100 %
Isotope ¹⁸⁵Re	184.952955(8) u	37.40(5) %	stable	5/2+
Isotope ¹⁸⁷Re	186.95575(1) u	62.60(5) %	4.33(7) × 10¹⁰ a	5/2+

NMR data

Nuclear magnetic properties and parameters of the NMR active Nuclide ¹⁸⁷Re

Isotope:¹⁸⁷Re-NMRQuantity:62.60(5) %Spin:5/2+Nuclearmagnetic moment
μ/μ_N:+ 3.2197(3)Gyromagnetic ratio γ:6.1682 · 10⁷ rad T^-1 s^-1
9.81700 MHz T^-1Nuclear g-factor:g_l = 1.28788Quadrupole moment Q:+ 2.07(2) barn (100 fm²)Resonance frequency:v₀ = 9.8170 MHz at 1 TRelative Sensitivity:[related to ¹H = 1.000]:
0.14300 (H₀ = const.)
2.6900 (v₀ = const.)

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 112) and isobaric (same nucleon number A = 187) with Rhenium-187. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 112	Isobar A = 187
70	¹⁸²Yb
71	¹⁸³Lu	¹⁸⁷Lu
72	¹⁸⁴Hf	¹⁸⁷Hf
73	¹⁸⁵Ta	¹⁸⁷Ta
74	¹⁸⁶W	¹⁸⁷W
75	¹⁸⁷Re	¹⁸⁷Re
76	¹⁸⁸Os	¹⁸⁷Os
77	¹⁸⁹Ir	¹⁸⁷Ir
78	¹⁹⁰Pt	¹⁸⁷Pt
79	¹⁹¹Au	¹⁸⁷Au
80	¹⁹²Hg	¹⁸⁷Hg
81	¹⁹³Tl	¹⁸⁷Tl
82	¹⁹⁴Pb	¹⁸⁷Pb
83	¹⁹⁵Bi	¹⁸⁷Bi
84	¹⁹⁶Po	¹⁸⁷Po
85	¹⁹⁷At
86	¹⁹⁸Rn
87	¹⁹⁹Fr