Isotopes of zinc

Naturally occurring zinc (₃₀Zn) is composed of the 5 stable isotopes ⁶⁴Zn, ⁶⁶Zn, ⁶⁷Zn, ⁶⁸Zn, and ⁷⁰Zn with ⁶⁴Zn being the most abundant (48.6% natural abundance). Twenty-eight radioisotopes have been characterised with the most stable being ⁶⁵Zn with a half-life of 243.94 days, and then ⁷²Zn with a half-life of 46.5 hours. All of the remaining radioactive isotopes have half-lives that are less than 14 hours and the majority of these have half-lives that are less than a second. This element also has 10 meta states.

Zinc has been proposed as a "salting" material for nuclear weapons. A jacket of isotopically enriched ⁶⁴Zn, irradiated by the intense high-energy neutron flux from an exploding thermonuclear weapon, would be transmuted to ⁶⁵Zn, which emits 1.115 MeV of gamma radiation in about half of decays, and would significantly increase the radioactivity of the weapon's fallout for several years. Such a weapon is not known to have ever been built, tested, or used.