What is an expressed power of the federal government that is not shared with the states?

An expressed power of the federal government that is not shared with the states is the authority to regulate interstate commerce. This power, granted by the Commerce Clause in the U.S. Constitution, allows Congress to create laws governing trade between states, which states cannot do independently. It ensures a unified economic policy across the nation, preventing individual states from imposing trade barriers that could disrupt the national economy.