Iridium-194

Properties and data of the isotope ¹⁹⁴Ir.

Contents

General data

Name of the isotope:Iridium-194; Ir-194Symbol:¹⁹⁴Ir or 19477IrMass number A:194 (= number of nucleons)Atomic number Z:77 (= number of protons)Neutrons N:117Isotopic mass:193.9650758(14) u (atomic weight of Iridium-194)Nuclide mass:193.9228396 u (calculated nuclear mass without electrons)Mass excess:-32.53168 MeVMass defect:1.651246836 u (per nucleus)Nuclear binding energy:1538.12652025 MeV (per nucleus)
7.92848722 MeV (average binding energy per nucleon)Separation energy:S_N = 6.06679(11) MeV (first neutron)
S_P = 6.4264(24) MeV (first proton)Half-life:19.28(13) hDecay constant λ:9.986560346933 × 10^-6 s^-1Specific activity α:3.116086689921 × 10⁺¹⁶ Bq g^-1
842185.59187076 Ci g^-1Spin and parity:
(nuclear angular momentum)1-Magnetic dipole moment:μ(μ_N) = + 0.39(1)Quadrupole moment Q:+ 0.339(12) barn (100 fm²)Nuclear g-factor:g_l = 0.39Year of discovery:1937

Radioactive Decay

Half-life T_½ = 19.28(13) h (hours) respectively 6.9408 × 10⁴ seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
β^-	¹⁹⁴Pt	100 %	2.2284(13) MeV

Parent Nuclides

Direct parent isotope is: ¹⁹⁴Os.

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
^194m1Ir	147.072(2) keV	31.85(24) ms	4+
^194m2Ir	190+x keV	171(11) d	(10,11)

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 117) and isobaric (same nucleon number A = 194) with Iridium-194. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 117	Isobar A = 194
71	¹⁸⁸Lu
72	¹⁸⁹Hf
73	¹⁹⁰Ta	¹⁹⁴Ta
74	¹⁹¹W	¹⁹⁴W
75	¹⁹²Re	¹⁹⁴Re
76	¹⁹³Os	¹⁹⁴Os
77	¹⁹⁴Ir	¹⁹⁴Ir
78	¹⁹⁵Pt	¹⁹⁴Pt
79	¹⁹⁶Au	¹⁹⁴Au
80	¹⁹⁷Hg	¹⁹⁴Hg
81	¹⁹⁸Tl	¹⁹⁴Tl
82	¹⁹⁹Pb	¹⁹⁴Pb
83	²⁰⁰Bi	¹⁹⁴Bi
84	²⁰¹Po	¹⁹⁴Po
85	²⁰²At	¹⁹⁴At
86	²⁰³Rn	¹⁹⁴Rn
87	²⁰⁴Fr
88	²⁰⁵Ra
89	²⁰⁶Ac
90	²⁰⁷Th