Gold-186

Properties and data of the isotope ¹⁸⁶Au.

Content

General data

Name of the isotope:Gold-186; Au-186Symbol:¹⁸⁶Au or 18679AuMass number A:186 (= number of nucleons)Atomic number Z:79 (= number of protons)Neutrons N:107Isotopic mass:185.965953(23) u (atomic weight of Gold-186)Nuclide mass:185.9226199 u (calculated nuclear mass without electrons)Mass excess:-31.71458 MeVMass defect:1.57937054 u (per nucleus)Nuclear binding energy:1471.17418179 MeV (per nucleus)
7.90953861 MeV (average binding energy per nucleon)Separation energy:S_N = 7.928(21) MeV (first neutron)
S_P = 2.32(3) MeV (first proton)Half-life:10.7(5) minDecay constant λ:0.010796685055451 s^-1Specific activity α:3.514549093205 × 10⁺¹⁹ Bq g^-1
949878133.29876 Ci g^-1Spin and parity:
(nuclear angular momentum)3-Magnetic dipole moment:μ(μ_N) = - 1.272(22)Quadrupole moment Q:+ 3.10(6) barn (100 fm²)Nuclear g-factor:g_l = -0.424Charge radius:5.4354(39) femtometer fmYear of discovery:1960

Radioactive Decay

Half-life T_½ = 10.7(5) min (minutes) respectively 6.42 × 10¹ seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
α	¹⁸²Ir	trace	4.912(14) MeV
EE/β⁺	¹⁸⁶Pt	100 %	6.15(3) MeV

Parent Nuclides

Direct parent isotope is: ¹⁸⁶Hg.

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
^186mAu	227.77(7) keV	110(10) ns	2+

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 107) and isobaric (same nucleon number A = 186) with Gold-186. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 107	Isobar A = 186
65	¹⁷²Tb
66	¹⁷³Dy
67	¹⁷⁴Ho
68	¹⁷⁵Er
69	¹⁷⁶Tm
70	¹⁷⁷Yb
71	¹⁷⁸Lu	¹⁸⁶Lu
72	¹⁷⁹Hf	¹⁸⁶Hf
73	¹⁸⁰Ta	¹⁸⁶Ta
74	¹⁸¹W	¹⁸⁶W
75	¹⁸²Re	¹⁸⁶Re
76	¹⁸³Os	¹⁸⁶Os
77	¹⁸⁴Ir	¹⁸⁶Ir
78	¹⁸⁵Pt	¹⁸⁶Pt
79	¹⁸⁶Au	¹⁸⁶Au
80	¹⁸⁷Hg	¹⁸⁶Hg
81	¹⁸⁸Tl	¹⁸⁶Tl
82	¹⁸⁹Pb	¹⁸⁶Pb
83	¹⁹⁰Bi	¹⁸⁶Bi
84	¹⁹¹Po	¹⁸⁶Po
85	¹⁹²At
86	¹⁹³Rn