Properties

Atomic Number	87
CAS Registry Number	7440-73-5
Chemical Symbol	Fr

History

The atomic number is 87 and the chemical symbol is Fr. The name derives from the country France where the French physicist Marguerite Perey from the Curie Institute in Paris France discovered it in 1939 in the alpha particle decay of actinium 227Ac -> 4He -> 223Fr which was known as actinium-K and has a half-life of 22 minutes. An earlier claim of discovery in 1930 with the element name Virginium was determined to be incorrect. A similar claim for discovery of the element with atomic number 87 and named moldavium was also determined to be incorrect. The longest half-life associated with this unstable element is 22 minute 223Fr.

Holden, Norman E., (2004). History of the origin of the chemical elements and their discoverers. National Nuclear Data Center. Retrieved from http://www.nndc.bnl.gov/content/elements.html