Iridium-186

Properties and data of the isotope ¹⁸⁶Ir.

Contents

General Data

Radioactive Decay

Parent Nuclides

Isotones und Isobares

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

General data

Name of the isotope:Iridium-186; Ir-186Symbol:¹⁸⁶Ir or 18677IrMass number A:186 (= number of nucleons)Atomic number Z:77 (= number of protons)Neutrons N:109Isotopic mass:185.957947(18) u (atomic weight of Iridium-186)Nuclide mass:185.9157108 u (calculated nuclear mass without electrons)Mass excess:-39.17212 MeVMass defect:1.589056308 u (per nucleus)Nuclear binding energy:1480.19641656 MeV (per nucleus)
7.95804525 MeV (average binding energy per nucleon)Separation energy:S_N = 6.91(3) MeV (first neutron)
S_P = 3.655(17) MeV (first proton)Half-life:16.64(3) hDecay constant λ:1.157096655582 × 10^-5 s^-1Specific activity α:3.766594080258 × 10⁺¹⁶ Bq g^-1
1017998.4000698 Ci g^-1Spin and parity:
(nuclear angular momentum)5+Magnetic dipole moment:μ(μ_N) = + 3.88(5)Quadrupole moment Q:- 2.55(3) barn (100 fm²)Nuclear g-factor:g_l = 0.776Charge radius:5.3900(1061) femtometer fmYear of discovery:1958

Radioactive Decay

Half-life T_½ = 16.64(3) h (hours) respectively 5.9904 × 10⁴ seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
EC/β⁺	¹⁸⁶Os	100 %	3.828(17) MeV

Parent Nuclides

Direct parent isotope is: ¹⁸⁶Pt.

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
^186mIr	+x keV	1.90(5) h	2-

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 109) and isobaric (same nucleon number A = 186) with Iridium-186. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 109	Isobar A = 186
68	¹⁷⁷Er
69	¹⁷⁸Tm
70	¹⁷⁹Yb
71	¹⁸⁰Lu	¹⁸⁶Lu
72	¹⁸¹Hf	¹⁸⁶Hf
73	¹⁸²Ta	¹⁸⁶Ta
74	¹⁸³W	¹⁸⁶W
75	¹⁸⁴Re	¹⁸⁶Re
76	¹⁸⁵Os	¹⁸⁶Os
77	¹⁸⁶Ir	¹⁸⁶Ir
78	¹⁸⁷Pt	¹⁸⁶Pt
79	¹⁸⁸Au	¹⁸⁶Au
80	¹⁸⁹Hg	¹⁸⁶Hg
81	¹⁹⁰Tl	¹⁸⁶Tl
82	¹⁹¹Pb	¹⁸⁶Pb
83	¹⁹²Bi	¹⁸⁶Bi
84	¹⁹³Po	¹⁸⁶Po
85	¹⁹⁴At
86	¹⁹⁵Rn