Iridium-171m

Properties and data of the isotope ^171mIr.

Contents

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

General data

Name of the isotope:Iridium-171m; Ir-171mSymbol:^171mIr or 171m77IrMass number A:171 (= number of nucleons)Atomic number Z:77 (= number of protons)Neutrons N:94Isotopic mass:170.97165(4) u (atomic weight of Iridium-171m)
Excitation energy: +x keVNuclide mass:170.9294138 u (calculated nuclear mass without electrons)Mass excess:-26.40785 MeVMass defect:1.445379568 u (per nucleus)Nuclear binding energy:1346.36239531 MeV (per nucleus)
7.8734643 MeV (average binding energy per nucleon)Half-life:1.2(1) sDecay constant λ:0.57762265046662 s^-1Specific activity α:2.046191155882 × 10⁺²¹ Bq g^-1
55302463672.497 Ci g^-1Spin and parity:
(nuclear angular momentum)(11/2-)

Radioactive Decay

Half-life T_½ = 1.2(1) s.

Decay mode	Daughter	Probability
α	¹⁶⁷Re	54(5) %
EC/β⁺	¹⁷¹Os	?
p	¹⁷⁰Os	?

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
¹⁷¹Ir		3.2 s	(1/2+)

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 94) and isobaric (same nucleon number A = 171) with Iridium-171m. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 94	Isobar A = 171
54	¹⁴⁸Xe
55	¹⁴⁹Cs
56	¹⁵⁰Ba
57	¹⁵¹La
58	¹⁵²Ce
59	¹⁵³Pr
60	¹⁵⁴Nd
61	¹⁵⁵Pm
62	¹⁵⁶Sm
63	¹⁵⁷Eu
64	¹⁵⁸Gd
65	¹⁵⁹Tb	¹⁷¹Tb
66	¹⁶⁰Dy	¹⁷¹Dy
67	¹⁶¹Ho	¹⁷¹Ho
68	¹⁶²Er	¹⁷¹Er
69	¹⁶³Tm	¹⁷¹Tm
70	¹⁶⁴Yb	¹⁷¹Yb
71	¹⁶⁵Lu	¹⁷¹Lu
72	¹⁶⁶Hf	¹⁷¹Hf
73	¹⁶⁷Ta	¹⁷¹Ta
74	¹⁶⁸W	¹⁷¹W
75	¹⁶⁹Re	¹⁷¹Re
76	¹⁷⁰Os	¹⁷¹Os
77	¹⁷¹Ir	¹⁷¹Ir
78	¹⁷²Pt	¹⁷¹Pt
79	¹⁷³Au	¹⁷¹Au
80	¹⁷⁴Hg	¹⁷¹Hg