Heavy elements are chemical elements with a high atomic mass, typically those with an atomic number greater than 92, such as uranium and plutonium. These elements are often found in the actinide and transactinide series of the periodic table. They are known for their dense nuclei and can be radioactive, meaning they can emit radiation as they decay over time. Due to their unique properties, heavy elements have various applications, including in nuclear energy and medicine. For example, uranium is used as fuel in nuclear reactors, while plutonium can be used in nuclear weapons and certain types of batteries.