Iridium-173

Properties and data of the isotope ¹⁷³Ir.

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-173; Ir-173Symbol:¹⁷³Ir or 17377IrMass number A:173 (= number of nucleons)Atomic number Z:77 (= number of protons)Neutrons N:96Isotopic mass:172.967505(12) u (atomic weight of Iridium-173)Nuclide mass:172.9252688 u (calculated nuclear mass without electrons)Mass excess:-30.2689 MeVMass defect:1.4668544 u (per nucleus)Nuclear binding energy:1366.36607247 MeV (per nucleus)
7.89806978 MeV (average binding energy per nucleon)Separation energy:S_N = 10.96(3) MeV (first neutron)
S_P = 0.314(15) MeV (first proton)Half-life:9.0(8) sDecay constant λ:0.077016353395549 s^-1Specific activity α:2.696530980620 × 10⁺²⁰ Bq g^-1
7287921569.2438 Ci g^-1Spin and parity:
(nuclear angular momentum)(3/2+.5/2+)Year of discovery:1967

Radioactive Decay

Half-life T_½ = 9.0(8) s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
α	¹⁶⁹Re	< 7 %	5.716(19) MeV
EC/β⁺	¹⁷³Os	> 93 %	7.170(19) MeV

Parent Nuclides

Direct parent isotope is: ¹⁷⁷Au.

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
^173mIr	226(18) keV	2.20(5) s	(11/2-)

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 96) and isobaric (same nucleon number A = 173) with Iridium-173. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 96	Isobar A = 173
55	¹⁵¹Cs
56	¹⁵²Ba
57	¹⁵³La
58	¹⁵⁴Ce
59	¹⁵⁵Pr
60	¹⁵⁶Nd
61	¹⁵⁷Pm
62	¹⁵⁸Sm
63	¹⁵⁹Eu
64	¹⁶⁰Gd
65	¹⁶¹Tb
66	¹⁶²Dy	¹⁷³Dy
67	¹⁶³Ho	¹⁷³Ho
68	¹⁶⁴Er	¹⁷³Er
69	¹⁶⁵Tm	¹⁷³Tm
70	¹⁶⁶Yb	¹⁷³Yb
71	¹⁶⁷Lu	¹⁷³Lu
72	¹⁶⁸Hf	¹⁷³Hf
73	¹⁶⁹Ta	¹⁷³Ta
74	¹⁷⁰W	¹⁷³W
75	¹⁷¹Re	¹⁷³Re
76	¹⁷²Os	¹⁷³Os
77	¹⁷³Ir	¹⁷³Ir
78	¹⁷⁴Pt	¹⁷³Pt
79	¹⁷⁵Au	¹⁷³Au
80	¹⁷⁶Hg	¹⁷³Hg
81	¹⁷⁷Tl
82	¹⁷⁸Pb