The actinide series consists of 15 chemical elements in the periodic table, ranging from actinium (Ac, atomic number 89) to lawrencium (Lr, atomic number 103). These elements are all radioactive and are known for their complex electron configurations, which contribute to their unique chemical properties. Most actinides are found in nature only in trace amounts and are typically produced synthetically in laboratories. Actinides are primarily known for their use in nuclear energy and weapons. Elements like uranium (U) and plutonium (Pu) are crucial for nuclear reactors and atomic bombs. The series also includes elements used in scientific research and medical applications, highlighting their significance in both energy production and technology.