Isotopes of rhodium
Naturally occurring rhodium is composed of only one stable isotope, 103Rh. The most stable radioisotopes are 101Rh with a half-life of 4.07 years, 102Rh with a half-life of 207 days, and 99Rh with a half-life of 16.1 days. Thirty other radioisotopes have been characterized ranging from 89Rh to 122Rh - these have half-lives that are less than an hour except 100Rh and 105Rh. There are also numerous meta states with the most stable being 102mRh with a half-life of 3.74 years and 101mRh with a half-life of 4.34 days.
The primary decay mode before the only stable isotope, 103Rh, is electron capture to ruthenium isotopes, and the primary mode after is beta emission to palladium isotopes. Mass numbers 102 and 104 are capable of decay in either sense.