Iridium-188
Properties and data of the isotope 188Ir.
See also: List of individual Iridium isotopes (and general data sources).
General data
Name of the isotope:Iridium-188; Ir-188Symbol:188Ir or 18877IrMass number A:188 (= number of nucleons)Atomic number Z:77 (= number of protons)Neutrons N:111Nucleon pairing (Z - N):odd - oddNuclear ratio (N/Z ratio):1.4415584415584 (= neutron-proton ratio)Neutron excess (N-Z):34Isotopic mass:187.958835(10) u (atomic weight of Iridium-188)Nuclide mass:187.9165988 u (calculated nuclear mass without electrons)Mass excess:-38.34495 MeVMass defect:1.60549814 u (per nucleus)Nuclear binding energy:1495.51188442 MeV (per nucleus)
7.95485045 MeV (average binding energy per nucleon)Separation energy:SN = 6.867(29) MeV (first neutron)
SP = 4.415(9) MeV (first proton)Half-life:41.5(5) hDecay constant λ:4.639539361177 × 10-6 s-1Specific activity α:1.494115484397 × 10+16 Bq g-1
403814.99578311 Ci g-1Spin and parity:
(nuclear angular momentum)1-Magnetic dipole moment:μ(μN) = + 0.302(10)Quadrupole moment Q:+ 0.484(6) barn (100 fm2)Nuclear g-factor:gl = 0.302Charge radius:5.3838(1061) femtometer fmYear of discovery:1950
Radioactive Decay
Half-life T½ = 41.5(5) h (hours) respectively 1.49400 × 105 seconds s.
Decay
mode | Daughter | Probability | Decay energy | γ energy
(intensity) |
|---|
| EC/β+ | 188Os | 100 % | 2.792(9) MeV | |
Parent Nuclides
Direct parent isotope is: 188Pt.
Isotones and Isobars
The following table shows the atomic nuclei that are isotonic (same neutron number N = 111) and isobaric (same nucleon number A = 188) with Iridium-188. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.
| Z | Isotone N = 111 | Isobar A = 188 |
|---|
| 70 | 181Yb | |
| 71 | 182Lu | 188Lu |
| 72 | 183Hf | 188Hf |
| 73 | 184Ta | 188Ta |
| 74 | 185W | 188W |
| 75 | 186Re | 188Re |
| 76 | 187Os | 188Os |
| 77 | 188Ir | 188Ir |
| 78 | 189Pt | 188Pt |
| 79 | 190Au | 188Au |
| 80 | 191Hg | 188Hg |
| 81 | 192Tl | 188Tl |
| 82 | 193Pb | 188Pb |
| 83 | 194Bi | 188Bi |
| 84 | 195Po | 188Po |
| 85 | 196At | 188At |
| 86 | 197Rn | |
External data and identifiers
Last update: 2020-10-21
Perma link: https://www.chemlin.org/isotope/iridium-188
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