Isotopes of promethium

Promethium (Pm) is a rare and radioactive element with the atomic number 61. It has a number of isotopes, most of which are unstable and radioactive. The most notable isotopes of promethium include: 1. **Promethium-145 (Pm-145)**: This isotope has a half-life of about 17.7 hours and decays into Neodymium-145.