Promethium is a chemical element with the symbol Pm and atomic number 61. It is a highly radioactive and rare element that is part of the lanthanide series, which consists of 15 elements with atomic numbers ranging from 57 to 71.

Key Characteristics of Promethium:

1. Radioactivity: Promethium is a highly radioactive element, and all of its isotopes are unstable. Its most stable isotope, promethium-145, has a half-life of only about 17.7 years. Due to its radioactive nature, promethium emits beta particles and gamma radiation.
2. Occurrence: Promethium is not found naturally on Earth in significant quantities. It is a synthetic element that can be produced in a laboratory through the irradiation of neodymium-146 with neutrons.
3. Chemical Properties: Promethium exhibits chemical properties similar to other lanthanides. It is a soft, silvery metal and is chemically reactive. However, due to its rarity and limited availability, its chemical properties have not been extensively studied.
4. Applications: Due to its rarity and radioactivity, promethium has limited practical applications. However, it has been used in certain niche areas such as nuclear batteries, where its radioactive decay provides a source of energy, and in some research and medical applications.
5. Biological Role: Promethium has no known biological role and is not naturally present in living organisms. Its highly radioactive nature makes it harmful to biological systems.

Promethium’s synthetic and radioactive properties make it a challenging element to study and utilize in practical applications. Its production and study contribute to our understanding of nuclear physics and the behavior of radioactive isotopes.