Francium

Name:
Francium
Detailed information:
Fr. Element of atomic number 87, group IA of the periodic table system, aw 223, valence of 1; it appears to exist only as radioactive isotopes. One isotope is actinium K (²²³Fr). Other isotopes have been made artificially: ²²³Fr is the longest-lived isotope, having a half-life of 21 minutes, and is the only natural isotope. Francium is the heaviest of the alkali-metal family.