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Oxygen-20

Properties and data of the isotope 20O.


Contents

 

Oxygen-20 isotope

Oxygen-20 is a radioisotope of the chemical element oxygen, which has 12 neutrons in its atomic nucleus in addition to the element-specific 8 protons; the sum of the number of these atomic nucleus building blocks results in a mass number of 20. The very short-lived, only artificially produced, unstable and thus radioactive nuclide has no practical significance; the study of 20O is exclusively for academic purposes and experimental research.

The discovery of the radioactive isotope was reported in 1959: According to it, oxygen-20 was produced by irradiating enriched oxygen-18 gas with tritons - Hydrogen-3 nuclei accelerated to 2.6 MeV:

18O(t,p)20O.

See also: list of Oxygen isotopes.

 

General data

Name of the isotope:Oxygen-20; O-20Symbol:20O or 208OMass number A:20 (= number of nucleons)Atomic number Z:8 (= number of protons)Neutrons N:12Isotopic mass:20.0040754(9) u (atomic weight of Oxygen-20)Nuclide mass:19.9996868 u (calculated nuclear mass without electrons)Mass excess:3.79621 MeVMass defect:0.162503848 u (per nucleus)Nuclear binding energy:151.37135939 MeV (per nucleus)
7.56856797 MeV (average binding energy per nucleon)
Separation energy:SN = 7.6080(28) MeV (first neutron)
SP = 19.349(16) MeV (first proton)
Half-life:13.51(5) sDecay constant λ:0.051306230981491 s-1Specific activity α:1.54486674981 × 10+21 Bq g-1
41753155400.405 Ci g-1
Spin and parity:
(nuclear angular momentum)
0+Isobaric spin: 2Mirror nucleus:Magnesium-20Year of discovery:1959

 

Radioactive Decay

Half-life T½ = 13.51(5) s respectively 1.351 × 101 seconds s.

Decay
mode
DaughterProbabilityDecay energyDetailsγ energy
(intensity)
β-20F100 %3.8136(9) MeVβ-: 1.1977(10) MeV [99.973(3) %]1.05678(3) MeV [99.975(3) %]

 

Parent Nuclides

Direct parent isotopes are: 20N, 21N.

 

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 12) and isobaric (same nucleon number A = 20) with Oxygen-20. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

 

ZIsotone N = 12Isobar A = 20
416Be
517B20B
618C20C
719N20N
820O20O
921F20F
1022Ne20Ne
1123Na20Na
1224Mg20Mg
1325Al
1426Si
1527P
1628S
1729Cl
1830Ar

 

External data and identifiers

Adopted Levels, Gammas:NuDat 20O

 

Literature and References

[1] - Nelson Jarmie, Myron G. Silbert:
Oxygen-20.
In: Physical Review Letters, 3, 50, (1959), DOI 10.1103/PhysRevLett.3.50.

 


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Last update: 2024-10-09


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