Astatine-219
Properties and data of the isotope 219At.
See also: list of Astatine isotopes.
General data
Name of the isotope:Astatine-219; At-219Symbol:219At or 21985AtMass number A:219 (= number of nucleons)Atomic number Z:85 (= number of protons)Neutrons N:134Isotopic mass:219.011161(3) u (atomic weight of Astatine-219)Nuclide mass:218.9645373 u (calculated nuclear mass without electrons)Mass excess:204007378407.35 MeVMass defect:-219010940.17377 u (per nucleus)Nuclear binding energy:-204007376706.23 MeV (per nucleus)
-931540532.90516 MeV (average binding energy per nucleon)Separation energy:SN = 5.773(12) MeV (first neutron)
SP = 5.250(4) MeV (first proton)Half-life:56(3) sDecay constant λ:0.012377628224285 s-1Specific activity α:34034713271335 Bq g-1
919.85711544149 Ci g-1Spin and parity:
(nuclear angular momentum)(9/2-)Year of discovery:1953
Radioactive Decay
Half-life T½ = 56(3) s respectively 5.6 × 101 seconds s.
Decay mode | Daughter | Probability | Decay energy | γ energy (intensity) |
---|
α | 215Bi | 93.6(10) % | 6.342(5) MeV | |
β- | 219Rn | 6.4(10) % | 1.5667(29) MeV | |
Parent Nuclides
Direct parent isotope is: 223Fr.
Isotones and Isobars
The following table shows the atomic nuclei that are isotonic (same neutron number N = 134) and isobaric (same nucleon number A = 219) with Astatine-219. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.
Z | Isotone N = 134 | Isobar A = 219 |
80 | 214Hg | |
81 | 215Tl | |
82 | 216Pb | 219Pb |
83 | 217Bi | 219Bi |
84 | 218Po | 219Po |
85 | 219At | 219At |
86 | 220Rn | 219Rn |
87 | 221Fr | 219Fr |
88 | 222Ra | 219Ra |
89 | 223Ac | 219Ac |
90 | 224Th | 219Th |
91 | 225Pa | 219Pa |
92 | 226U | 219U |
93 | 227Np | 219Np |
94 | 228Pu | |
95 | 229Am | |
External data and identifiers
Last update: 2023-04-15
Perma link: https://www.chemlin.org/isotope/astatine-219
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