Iridium-194m1

Properties and data of the isotope ^194m1Ir.

Contents

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

General data

Name of the isotope:Iridium-194m1; Ir-194m1Symbol:^194m1Ir or 194m177IrMass number A:194 (= number of nucleons)Atomic number Z:77 (= number of protons)Neutrons N:117Nucleon pairing (Z - N):odd - oddNuclear ratio (N/Z ratio):1.5194805194805 (= neutron-proton ratio)Neutron excess (N-Z):40Excitation energy:147.072(2) keVIsotopic mass:193.9650758(14) u (atomic weight of Iridium-194m1)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)Half-life:31.85(24) msDecay constant λ:21.762862811929 s^-1Specific activity α:6.790623076109 × 10⁺²² Bq g^-1
1835303534083.7 Ci g^-1Spin and parity:
(nuclear angular momentum)4+

Radioactive Decay

Half-life T_½ = 31.85(24) ms respectively 3.185 × 10^-2 seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
Iso	¹⁹⁴Ir	100 %

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
¹⁹⁴Ir		19.28(13) h	1-
^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-194m1. 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