Iridium-168m

Properties and data of the isotope ¹⁶⁸Ir.

Contents

General data

Name of the isotope:Iridium-168m; Ir-168mSymbol:¹⁶⁸Ir or 16877IrMass number A:168 (= number of nucleons)Atomic number Z:77 (= number of protons)Neutrons N:91Isotopic mass:167.97996(6) u (atomic weight of Iridium-168m)
Excitation energy: +x keVNuclide mass:167.9377238 u (calculated nuclear mass without electrons)Mass excess:-18.66714 MeVMass defect:1.41107482 u (per nucleus)Nuclear binding energy:1314.40772838 MeV (per nucleus)
7.82385553 MeV (average binding energy per nucleon)Half-life:159 msDecay constant λ:4.3594162299368 s^-1Specific activity α:1.572037042142 × 10⁺²² Bq g^-1
424874876254.62 Ci g^-1Spin and parity:
(nuclear angular momentum)

Radioactive Decay

Half-life T_½ = 159 ms respectively 1.59 × 10^-1 seconds s.

Decay mode	Daughter	Probability
α	¹⁶⁴Re	77(9) %
p	¹⁶⁷Os	?
ε ?	¹⁶⁸Os	23(9) %

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
¹⁶⁸Ir		222 ms

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 91) and isobaric (same nucleon number A = 168) with Iridium-168m. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 91	Isobar A = 168
52	¹⁴³Te
53	¹⁴⁴I
54	¹⁴⁵Xe
55	¹⁴⁶Cs
56	¹⁴⁷Ba
57	¹⁴⁸La
58	¹⁴⁹Ce
59	¹⁵⁰Pr
60	¹⁵¹Nd
61	¹⁵²Pm
62	¹⁵³Sm
63	¹⁵⁴Eu	¹⁶⁸Eu
64	¹⁵⁵Gd	¹⁶⁸Gd
65	¹⁵⁶Tb	¹⁶⁸Tb
66	¹⁵⁷Dy	¹⁶⁸Dy
67	¹⁵⁸Ho	¹⁶⁸Ho
68	¹⁵⁹Er	¹⁶⁸Er
69	¹⁶⁰Tm	¹⁶⁸Tm
70	¹⁶¹Yb	¹⁶⁸Yb
71	¹⁶²Lu	¹⁶⁸Lu
72	¹⁶³Hf	¹⁶⁸Hf
73	¹⁶⁴Ta	¹⁶⁸Ta
74	¹⁶⁵W	¹⁶⁸W
75	¹⁶⁶Re	¹⁶⁸Re
76	¹⁶⁷Os	¹⁶⁸Os
77	¹⁶⁸Ir	¹⁶⁸Ir
78	¹⁶⁹Pt	¹⁶⁸Pt
79	¹⁷⁰Au
80	¹⁷¹Hg