Uranium is the heaviest naturally occurring element. It is found in Row 7 of the periodic table. Uranium's atomic number is 92, its atomic mass is 238.0289, and its chemical symbol is U.

Properties

All isotopes of uranium are radioactive. The most common, uranium-238, is also the most stable with a half life of 4.468 x 10⁹ years. Uranium is a silvery metal that is both ductile and malleable. It has a melting point of 2,070.1°F (1,132.3°C), a boiling point of about 6,904°F (3,818°C), and a density of 19.05 grams per cubic centimeter. The element is relatively reactive, combining with oxygen, sulfur, fluorine, chlorine, bromine, and phosphorus. It also dissolves in most acids and reacts slowly with water to form compounds that tend to be yellowish or green in color.

Occurrence and Extraction

Uranium is a relatively uncommon element in the Earth's crust with an abundance estimated at about 1-...