Actinium-226 is a radioactive isotope of actinium, a rare earth metal. It has a half-life of about 29.4 hours, meaning it takes this amount of time for half of a sample to decay. Actinium-226 is primarily produced from the decay of thorium-230 and is used in various scientific and medical applications, including targeted alpha-particle therapy for cancer treatment. This isotope emits alpha particles, which can be harmful to living tissues if ingested or inhaled. Due to its radioactivity, handling Actinium-226 requires strict safety precautions to minimize exposure. It is also used in research to study the properties of heavy elements and their interactions.