Iridium-191m1
Properties and data of the isotope 191m1Ir.
See also: List of individual Iridium isotopes (and general data sources).
General data
Name of the isotope:Iridium-191m1; Ir-191m1Symbol:191m1Ir or 191m177IrMass number A:191 (= number of nucleons)Atomic number Z:77 (= number of protons)Neutrons N:114Nucleon pairing (Z - N):odd - evenNuclear ratio (N/Z ratio):1.4805194805195 (= neutron-proton ratio)Neutron excess (N-Z):37Excitation energy:171.29(4) keVIsotopic mass:190.96059(2) u (atomic weight of Iridium-191m1)Nuclide mass:190.9183538 u (calculated nuclear mass without electrons)Mass excess:-36.71018 MeVMass defect:1.629737888 u (per nucleus)Nuclear binding energy:1518.09106424 MeV (per nucleus)
7.94812076 MeV (average binding energy per nucleon)Half-life:4.899(23) sDecay constant λ:0.14148748327413 s-1Specific activity α:4.484513443130 × 10+20 Bq g-1
12120306603.055 Ci g-1Spin and parity:
(nuclear angular momentum)11/2-Magnetic dipole moment:μ(μN) = + 6.03(4)Nuclear g-factor:gl = 1.0963636363636
Radioactive Decay
Half-life T½ = 4.899(23) s.
Decay
mode | Daughter | Probability | Decay energy | γ energy
(intensity) |
|---|
| Iso | 191Ir | 100 % | | |
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 |
|---|
| 191Ir | | stable | 3/2+ |
| 191m2Ir | 2046.7+x keV | 5.5(7) s | |
Isotones and Isobars
The following table shows the atomic nuclei that are isotonic (same neutron number N = 114) and isobaric (same nucleon number A = 191) with Iridium-191m1. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.
| Z | Isotone N = 114 | Isobar A = 191 |
|---|
| 70 | 184Yb | |
| 71 | 185Lu | |
| 72 | 186Hf | |
| 73 | 187Ta | 191Ta |
| 74 | 188W | 191W |
| 75 | 189Re | 191Re |
| 76 | 190Os | 191Os |
| 77 | 191Ir | 191Ir |
| 78 | 192Pt | 191Pt |
| 79 | 193Au | 191Au |
| 80 | 194Hg | 191Hg |
| 81 | 195Tl | 191Tl |
| 82 | 196Pb | 191Pb |
| 83 | 197Bi | 191Bi |
| 84 | 198Po | 191Po |
| 85 | 199At | 191At |
| 86 | 200Rn | |
| 87 | 201Fr | |
| 88 | 202Ra | |
| 89 | 203Ac | |
Last update: 2020-10-21
Perma link: https://www.chemlin.org/isotope/iridium-191m1
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