Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Uranium is a silvery-white metallic chemical element in the actinide series of the periodic table, with symbol U and atomic number 92 and it is weakly radioactive because all its isotopes are unstable. Many contemporary uses of uranium exploit its unique nuclear properties. In sufficient concentration, these isotopes maintain a sustained nuclear chain reaction. This generates the heat in nuclear power reactors, and produces the fissile material for nuclear weapons. Depleted uranium is used in kinetic energy penetrators and armor plating. Learn more about uranium, its isotopes and their many applications in this book.