Isotopes of sodium

There are 20 isotopes of <a href="/facts/Sodium/eYuSPu2V">sodium</a> (11Na), ranging from 17Na to 39Na (except for the still-unknown 36Na and 38Na), and five <a href="/facts/Nuclear_isomer/L8DHcqnk">isomers</a> (two for 22Na, and one each for 24Na, 26Na, and 32Na). 23Na is the only <a href="/facts/Stable_nuclide/vC0VVvqN">stable</a> (and the only <a href="/facts/Primordial_nuclide/lFAUqHDv">primordial</a>) isotope. It is considered a <a href="/facts/Monoisotopic_element/WzpKpVfg">monoisotopic element</a> and it has a <a href="/facts/Standard_atomic_weight/8arqbQsq">standard atomic weight</a> of 22.98976928(2). Sodium has two <a href="/facts/Radioactive/Ya6FVjt4">radioactive</a> <a href="/facts/Cosmogenic/TlJwc4wV">cosmogenic</a> isotopes (22Na, with a <a href="/facts/Half-life/kGVH8BAB">half-life</a> of 2.6019(6) years; and <a href="/facts/Sodium-24/dGhdEPWX">24Na</a>, with a half-life of 14.9560(15) h). With the exception of those two isotopes, all other isotopes have <a href="/facts/Half-lives/kGVH8BAB">half-lives</a> under a minute, most under a second. The shortest-lived is the unbound 18Na, with a half-life of 1.3(4)×10−21 seconds (although the half-life of the similarly unbound 17Na is not measured).
Acute neutron radiation exposure (e.g., from a nuclear <a href="/facts/Criticality_accident/c68hQvNh">criticality accident</a>) converts some of the stable 23Na (in the form of Na+ ion) in human blood plasma to 24Na. By measuring the concentration of this isotope, the neutron radiation dosage to the victim can be computed.
22Na is a <a href="/facts/Positron/HgV4zBzA">positron</a>-emitting isotope with a remarkably long half-life. It is used to create test-objects and point-sources for <a href="/facts/Positron_emission_tomography/5SmcW6qz">positron emission tomography</a>.

Isotopes of sodium open-in-new

Isotopes of sodium