Does sodium have any isotopes? Is it radioactive?
Sodium has one naturally occurring isotope. The nucleus of this isotope contains 11 protons and 12 neutrons and is not radioactive. There are 18 other known isotopes of sodium. All are radioactive. Sodium-22, sodium's most stable radioactive isotope, has a half-life of 2.6 years.
Steve Gagnon, Science Education Specialist (Other answers by Steve Gagnon)