Natural zinc (30Zn) is composed of the 5 stable isotopes 64Zn, 66Zn, 67Zn, 68Zn, and 70Zn; and 64Zn is the most abundant. Twenty-eight radioisotopes have been characterized; the most stable is 65Zn with a half-life of 243.94 days, and then 72Zn. All other isotopes have half-lives of less than 14 hours and most of these have half-lives of less than 1 second. This element also has 10 meta states.