All of the elements have some isotopes that are radioactive ( radioisotopes ), although not all of these radioisotopes occur naturally. Source: Internet
All other radioisotopes have ground-state half lives not greater than 1.117 days, and most have half lives under 3 hours. Source: Internet
All the remaining radioisotopes have half-lives that are less than 2 days, and the majority of these have half-lives that are less than 48 seconds. Source: Internet
At least 23 radioisotopes are known. Source: Internet
DGNAA is applicable to the vast majority of elements that form artificial radioisotopes. Source: Internet
Eighteen radioisotopes have been isolated and described, the most stable being 53 Mn with a half-life of 3.7 million years, 54 Mn with a half-life of 312.3 days, and 52 Mn with a half-life of 5.591 days. Source: Internet