A transuranium element is any chemical element that has an atomic number greater than that of uranium, which is 92. These elements are not found naturally on Earth and are typically created in laboratories or nuclear reactors through nuclear reactions. They are part of the actinide series and include elements like neptunium, plutonium, and americium. Transuranium elements are often radioactive and have various applications, including in nuclear energy and medicine. Due to their instability, they can decay into other elements over time, emitting radiation. Their study helps scientists understand nuclear processes and the behavior of heavy elements.