Isotopes of sodium
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There are 20 known isotopes of sodium (11Na), ranging from 17
Na to 39
Na (except for 36Na and 38Na),[4] and five isomers. 23
Na is the only stable (and the only primordial) isotope. It is considered a monoisotopic element and it has a standard atomic weight given by that isotope. Sodium has two radioactive cosmogenic isotopes (22
Na, with a half-life of 2.6019 years; and 24
Na, with a half-life of 14.9560(15) h). With the exception of those two isotopes, all other isotopes have half-lives under a minute, most under a second.
Acute neutron radiation exposure (e.g., from a nuclear criticality accident) converts some of the stable 23
Na in human blood plasma to 24
Na. The neutron radiation dosage to the victim can be assessed thus by prompt measurement of the radioisotope.
22
Na is a positron-emitting isotope with a relatively long half-life, about 2.6 years. It is used to create test-objects and point-sources for positron emission tomography.
- ^ Kondev, F. G.; Wang, M.; Huang, W. J.; Naimi, S.; Audi, G. (2021). "The NUBASE2020 evaluation of nuclear properties" (PDF). Chinese Physics C. 45 (3): 030001. doi:10.1088/1674-1137/abddae.
- ^ "Standard Atomic Weights: Sodium". CIAAW. 2005.
- ^ Prohaska, Thomas; Irrgeher, Johanna; Benefield, Jacqueline; Böhlke, John K.; Chesson, Lesley A.; Coplen, Tyler B.; Ding, Tiping; Dunn, Philip J. H.; Gröning, Manfred; Holden, Norman E.; Meijer, Harro A. J. (2022-05-04). "Standard atomic weights of the elements 2021 (IUPAC Technical Report)". Pure and Applied Chemistry. doi:10.1515/pac-2019-0603. ISSN 1365-3075.
- ^ Ahn, D.S.; et al. (2022-11-14). "Discovery of 39Na". Physical Review Letters. 129 (21) 212502: 212502. Bibcode:2022PhRvL.129u2502A. doi:10.1103/PhysRevLett.129.212502. PMID 36461972. S2CID 253591660.