Sodium-18
Properties and data of the isotope 18Na.
Sodium-18 is a radioisotope of the chemical element sodium, which, in addition to the element-specific 11 protons, has 7 neutrons in the atomic nucleus, resulting in the mass number 18. The very short-lived, unstable and therefore radioactive nuclide, which can only be produced artificially, has no practical significance; The study of 18Na serves exclusively academic purposes.
See also: list of Sodium isotopes.
General data
Name of the isotope:Sodium-18; Na-18Symbol:18Na or 1811NaMass number A:18 (= number of nucleons)Atomic number Z:11 (= number of protons)Neutrons N:7Isotopic mass:18.02688(10) u (atomic weight of Sodium-18)Nuclide mass:18.0208457 u (calculated nuclear mass without electrons)Mass excess:25.03856 MeVMass defect:0.119849764 u (per nucleus)Nuclear binding energy:111.63933607 MeV (per nucleus)
6.20218534 MeV (average binding energy per nucleon)Separation energy:SN = 17.753(111) MeV (first neutron)Half-life:1.3(4) zsDecay constant λ:5.331901388922 × 10+20 s-1Specific activity α:1.783858956410 × 10+43 Bq g-1
4.821240422730 × 10+32 Ci g-1Spin and parity:
(nuclear angular momentum)(1)-Mirror nucleus:Nitrogen-18Year of discovery:2004
Radioactive Decay
Half-life T½ = 1.3(4) zs respectively 1.3 × 10-21 seconds s.
Decay mode | Daughter | Probability | Decay energy | γ energy (intensity) |
---|
p | 17Ne | ? 100 % | | |
Isotones and Isobars
The following table shows the atomic nuclei that are isotonic (same neutron number N = 7) and isobaric (same nucleon number A = 18) with Sodium-18. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.
OZ | Isotone N = 7 | Isobar A = 18 |
2 | 9He | |
3 | 10Li | |
4 | 11Be | |
5 | 12B | 18B |
6 | 13C | 18C |
7 | 14N | 18N |
8 | 15O | 18O |
9 | 16F | 18F |
10 | 17Ne | 18Ne |
11 | 18Na | 18Na |
12 | 19Mg | |
External data and identifiers
Literature and References
[1] - M. Assie et al.:
Spectroscopy of the unbound nucleus 18Na.
In: International Journal of Modern Physics E, 20 (04), 971-975, (2011), DOI 10.1142/S0218301311019088.
Last update: 2023-11-02
Perma link: https://www.chemlin.org/isotope/sodium-18
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