Uranium is a silvery-white metallic chemical element in the actinide series of the periodic table with atomic number 92. It is assigned the chemical symbol U. A uranium atom has 92 protons and 92 electrons of which 6 are valence electrons. The uranium nucleus binds between 141 and 146 neutrons establishing six isotopes the most common of which are uranium-238 (146 neutrons) and uranium-235 (143 neutrons). All isotopes are unstable and uranium is weakly radioactive.
