Iridium-178

Properties and data of the isotope ¹⁷⁸Ir.

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-178; Ir-178Symbol:¹⁷⁸Ir or 17877IrMass number A:178 (= number of nucleons)Atomic number Z:77 (= number of protons)Neutrons N:101Isotopic mass:177.961082(21) u (atomic weight of Iridium-178)Nuclide mass:177.9188458 u (calculated nuclear mass without electrons)Mass excess:-36.25188 MeVMass defect:1.51660198 u (per nucleus)Nuclear binding energy:1412.70564476 MeV (per nucleus)
7.93654857 MeV (average binding energy per nucleon)Separation energy:S_N = 8.276(28) MeV (first neutron)
S_P = 1.584(25) MeV (first proton)Half-life:12(2) sDecay constant λ:0.057762265046662 s^-1Specific activity α:1.965268341807 × 10⁺²⁰ Bq g^-1
5311536058.9403 Ci g^-1Spin and parity:
(nuclear angular momentum)Year of discovery:1972

Radioactive Decay

Half-life T_½ = 12(2) s respectively 1.2 × 10¹ seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
EC/β⁺	¹⁷⁸Os	100 %	7.292(24) MeV

Parent Nuclides

Direct parent isotopes are: ¹⁸²Au, ¹⁷⁸Pt.

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 101) and isobaric (same nucleon number A = 178) with Iridium-178. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 101	Isobar A = 178
58	¹⁵⁹Ce
59	¹⁶⁰Pr
60	¹⁶¹Nd
61	¹⁶²Pm
62	¹⁶³Sm
63	¹⁶⁴Eu
64	¹⁶⁵Gd
65	¹⁶⁶Tb
66	¹⁶⁷Dy
67	¹⁶⁸Ho
68	¹⁶⁹Er
69	¹⁷⁰Tm	¹⁷⁸Tm
70	¹⁷¹Yb	¹⁷⁸Yb
71	¹⁷²Lu	¹⁷⁸Lu
72	¹⁷³Hf	¹⁷⁸Hf
73	¹⁷⁴Ta	¹⁷⁸Ta
74	¹⁷⁵W	¹⁷⁸W
75	¹⁷⁶Re	¹⁷⁸Re
76	¹⁷⁷Os	¹⁷⁸Os
77	¹⁷⁸Ir	¹⁷⁸Ir
78	¹⁷⁹Pt	¹⁷⁸Pt
79	¹⁸⁰Au	¹⁷⁸Au
80	¹⁸¹Hg	¹⁷⁸Hg
81	¹⁸²Tl	¹⁷⁸Tl
82	¹⁸³Pb	¹⁷⁸Pb
83	¹⁸⁴Bi