Naturally occurring vanadium (23V) is composed of one stable isotope, 51V, and one radioactive isotope, 50V, with a half-life of 2.71×1017 years. Twenty-five artificial radioisotopes have been characterized, ranging from 43V to 68V. The most stable of these are 49V with a half-life of 330 days and 48V with a half-life of 15.9735 days. All of the remaining radioactive isotopes have half-lives shorter than an hour, with the majority of them below 10 seconds. Seven metastable excited states have also been observed, two of which are for 60V.