Polonium-198
Properties and data of the isotope 198Po.
See also: List of individual Polonium isotopes (and general data sources).
General data
Name of the isotope:Polonium-198; Po-198Symbol:198Po or 19884PoMass number A:198 (= number of nucleons)Atomic number Z:84 (= number of protons)Neutrons N:114Nucleon pairing (Z - N):even - evenNuclear ratio (N/Z ratio):1.3571428571429 (= neutron-proton ratio)Neutron excess (N-Z):30Isotopic mass:197.983389(19) u (atomic weight of Polonium-198)Nuclide mass:197.9373137 u (calculated nuclear mass without electrons)Mass excess:-15.47305 MeVMass defect:1.661714112 u (per nucleus)Nuclear binding energy:1547.87672504 MeV (per nucleus)
7.81755922 MeV (average binding energy per nucleon)Separation energy:SN = 10.19(5) MeV (first neutron)
SP = 3.075(19) MeV (first proton)Half-life:1.760(24) minDecay constant λ:0.0065638937553025 s-1Specific activity α:2.006532628634 × 10+19 Bq g-1
542306115.84705 Ci g-1Spin and parity:
(nuclear angular momentum)0+Charge radius:5.5146(178) femtometer fmYear of discovery:1965
Radioactive Decay
Half-life T½ = 1.760(24) min (minutes) respectively 1.056 × 102 seconds s.
Decay
mode | Daughter | Probability | Decay energy | γ energy
(intensity) |
|---|
| α | 194Pb | 57(2) % | 6.3097(14) MeV | |
| EC/β+ | 198Bi | 43(2) % | 3.90(3) MeV | |
Parent Nuclides
Direct parent isotope is: 202Rn.
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 |
|---|
| 198m1Po | 2565.92(20) keV | 200(20) ns | 11- |
| 198m2Po | 2691.86+x keV | 0.75(5) μs | 12+ |
Isotones and Isobars
The following table shows the atomic nuclei that are isotonic (same neutron number N = 114) and isobaric (same nucleon number A = 198) with Polonium-198. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.
| Z | Isotone N = 114 | Isobar A = 198 |
|---|
| 70 | 184Yb | |
| 71 | 185Lu | |
| 72 | 186Hf | |
| 73 | 187Ta | |
| 74 | 188W | |
| 75 | 189Re | 198Re |
| 76 | 190Os | 198Os |
| 77 | 191Ir | 198Ir |
| 78 | 192Pt | 198Pt |
| 79 | 193Au | 198Au |
| 80 | 194Hg | 198Hg |
| 81 | 195Tl | 198Tl |
| 82 | 196Pb | 198Pb |
| 83 | 197Bi | 198Bi |
| 84 | 198Po | 198Po |
| 85 | 199At | 198At |
| 86 | 200Rn | 198Rn |
| 87 | 201Fr | |
| 88 | 202Ra | |
| 89 | 203Ac | |
External data and identifiers
Last update: 2020-10-07
Perma link: https://www.chemlin.org/isotope/polonium-198
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