87
223.00
Fr
Francium
Identification
CAS Number: 7440-73-5
Discovery Year: 1939
Discoverer: Marguerite Derey
Discovery Location: France
Properties
Atomic Dimensions
Electronic Structure
Electron Config: [Rn] 7s
Block: s
Period: 7 →Group: 1 →Electronegativity: 0.7 →Electron Affinity: 0.486 eV →Oxidation States: +2
Abundance & Geochemistry
Geochemical Class: U/Th decay series
Goldschmidt Class: synthetic
About
Radioactive element, belongs to group 1 of the periodic table. Found in uranium and thorium ores. The 22 known isotopes are all radioactive, with the most stable being Fr-223. Its existence was confirmed in 1939 by Marguerite Perey.
Isotopes
Fr-212 212 ☢ 20.0 min
Fr-222 222 ☢ 14.2 min
Fr-223 223 ☢ 22.0 min
