Actinide

Actinides are a group of 15 chemical elements found in the periodic table from actinium to lawrencium. They are characterized by having electrons in their 5f orbitals, which gives them unique chemical and physical properties. Most actinides are radioactive, meaning they emit energy as they decay, and many are used in nuclear reactors and scientific research. They are typically heavy, dense metals, with some, like uranium and plutonium, capable of sustaining nuclear reactions. Due to their radioactivity, handling actinides requires specialized safety measures.