Iridium-174m

Properties and data of the isotope ¹⁷⁴Ir.

Content

General data

Name of the isotope:Iridium-174m; Ir-174mSymbol:¹⁷⁴Ir or 17477IrMass number A:174 (= number of nucleons)Atomic number Z:77 (= number of protons)Neutrons N:97Isotopic mass:173.966867(26) u (atomic weight of Iridium-174m)
Excitation energy: 193(11) keVNuclide mass:173.9246308 u (calculated nuclear mass without electrons)Mass excess:-30.86319 MeVMass defect:1.476157316 u (per nucleus)Nuclear binding energy:1375.03168291 MeV (per nucleus)
7.90248094 MeV (average binding energy per nucleon)Half-life:4.9(3) sDecay constant λ:0.14145860827754 s^-1Specific activity α:4.924183034092 × 10⁺²⁰ Bq g^-1
13308602794.844 Ci g^-1Spin and parity:
(nuclear angular momentum)(7+)

Radioactive Decay

Half-life T_½ = 4.9(3) s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
α	¹⁷⁰Re	2.5(3) %
EE	¹⁷⁴Os	97.5(3) %

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
¹⁷⁴Ir		7.9(6) s	(3+)

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 97) and isobaric (same nucleon number A = 174) with Iridium-174m. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 97	Isobar A = 174
56	¹⁵³Ba
57	¹⁵⁴La
58	¹⁵⁵Ce
59	¹⁵⁶Pr
60	¹⁵⁷Nd
61	¹⁵⁸Pm
62	¹⁵⁹Sm
63	¹⁶⁰Eu
64	¹⁶¹Gd
65	¹⁶²Tb
66	¹⁶³Dy	¹⁷⁴Dy
67	¹⁶⁴Ho	¹⁷⁴Ho
68	¹⁶⁵Er	¹⁷⁴Er
69	¹⁶⁶Tm	¹⁷⁴Tm
70	¹⁶⁷Yb	¹⁷⁴Yb
71	¹⁶⁸Lu	¹⁷⁴Lu
72	¹⁶⁹Hf	¹⁷⁴Hf
73	¹⁷⁰Ta	¹⁷⁴Ta
74	¹⁷¹W	¹⁷⁴W
75	¹⁷²Re	¹⁷⁴Re
76	¹⁷³Os	¹⁷⁴Os
77	¹⁷⁴Ir	¹⁷⁴Ir
78	¹⁷⁵Pt	¹⁷⁴Pt
79	¹⁷⁶Au	¹⁷⁴Au
80	¹⁷⁷Hg	¹⁷⁴Hg
81	¹⁷⁸Tl
82	¹⁷⁹Pb