Periodic Table ~ Uranium ~ Element ~ CAS 7440-61-1

Uranium

Name	Uranium
Symbol	U
Atomic Weight	238.02891
Atomic Number	92
CAS ID	7440-61-1
Group Number
Group Name	Actinoid
Period Number	7
Origin of Name	Named after the planet Uranus.
Year Discovered	1789
Discovery Credits	Discovered by M. H. Klaproth at Berlin, German; isolated in 1841 by E. M. Pleigot at Paris, France
Class	Metallic
Color	Metallic Gray
Standard State	Solid at 77 F & 298 K
Description	Radioactive silvery metal. malleable, ductile, and tarnishes in air. Attacked by steam and acids but not by alkalis. Used as nuclear fuel and in nuclear weapons. Diagnostic tests: Uranium is usually detected by radioactivity (due, in part, to the daughter elements such as radium). Thorium is also naturally radioactive; however, many uranium minerals are generally yellow or green and fluorescent. With a borax bead test in the oxidizing flame, the bead is yellow to brownish red color while hot and is colorless to yellow when cold. This test is very similar to iron. The Na₂(NH₄)(PO₄) bead test for uranium is a much better test, under oxidizing conditions the bead is clear yellow (hot) yielding slightly greenish yellow on cooling. In the reducing flame, it becomes a fine green color when hot or cold.