Lead-188
Properties and data of the isotope 188Pb.
See also: List of individual Lead isotopes (and general data sources).
General data
Name of the isotope:Lead-188; Pb-188Symbol:188Pb or 18882PbMass number A:188 (= number of nucleons)Atomic number Z:82 (= number of protons)Neutrons N:106Nucleon pairing (Z - N):even - evenNuclear ratio (N/Z ratio):1.2926829268293 (= neutron-proton ratio)Neutron excess (N-Z):24Isotopic mass:187.980875(11) u (atomic weight of Lead-188)Nuclide mass:187.9358966 u (calculated nuclear mass without electrons)Mass excess:-17.81482 MeVMass defect:1.57925872 u (per nucleus)Nuclear binding energy:1471.07002213 MeV (per nucleus)
7.82484054 MeV (average binding energy per nucleon)Separation energy:SN = 10.900(12) MeV (first neutron)
SP = 2.660(13) MeV (first proton)Half-life:25.5(1) sDecay constant λ:0.0271822423749 s-1Specific activity α:8.753758955646 × 10+19 Bq g-1
2365880798.8234 Ci g-1Spin and parity:
(nuclear angular momentum)0+Charge radius:5.4139(25) femtometer fmYear of discovery:1972
Radioactive Decay
Half-life T½ = 25.5(1) s respectively 2.55 × 101 seconds s.
Decay
mode | Daughter | Probability | Decay energy | γ energy
(intensity) |
|---|
| α | 184Hg | 8.5(5) % | 6.109(3) MeV | |
| β+ | 188Tl | 91.5(5) % | 4.52(3) MeV | |
Parent Nuclides
Direct parent isotopes are: 188Bi, 192Po.
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 |
|---|
| 188m1Pb | 2577.2(4) keV | 800(20) ns | (8-) |
| 188m2Pb | 4783.4(7) keV | 0.44(6) μs | (19-) |
Isotones and Isobars
The following table shows the atomic nuclei that are isotonic (same neutron number N = 106) and isobaric (same nucleon number A = 188) with Lead-188. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.
| Z | Isotone N = 106 | Isobar A = 188 |
|---|
| 64 | 170Gd | |
| 65 | 171Tb | |
| 66 | 172Dy | |
| 67 | 173Ho | |
| 68 | 174Er | |
| 69 | 175Tm | |
| 70 | 176Yb | |
| 71 | 177Lu | 188Lu |
| 72 | 178Hf | 188Hf |
| 73 | 179Ta | 188Ta |
| 74 | 180W | 188W |
| 75 | 181Re | 188Re |
| 76 | 182Os | 188Os |
| 77 | 183Ir | 188Ir |
| 78 | 184Pt | 188Pt |
| 79 | 185Au | 188Au |
| 80 | 186Hg | 188Hg |
| 81 | 187Tl | 188Tl |
| 82 | 188Pb | 188Pb |
| 83 | 189Bi | 188Bi |
| 84 | 190Po | 188Po |
| 85 | 191At | 188At |
External data and identifiers
Last update: 2020-10-22
Perma link: https://www.chemlin.org/isotope/lead-188
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