Francium was discovered by Marguerite Catherine Perey, a French chemist, in 1939 while analyzing actinium's decay sequence.
Name: Francium
Symbol: Fr
Atomic number: 87
Atomic weight: 223.02
State:solid
Group, period, block: 1, 7, s
Color: metallic
Classification: alkali metal
Electron configuration: 7s1
2,8,18,32,18,8,1
Physical properties
Density: 1.87 g/cm-3
Melting point: 300 K,27 °C,80 °F
Boiling point: 950 K,677 °C,1250 °F
Atomic properties
Oxidation states: 1
Electronegativity: 0.7 (Pauling scale)
Ionization energies: 1st: 380 kJ·mol-1
Covalent radius: 260 pm
Van der Waals radius: 348 pm
- Fr
Electron Configuration
Isotopes
Francium has no stable isotopes. Its most stable isotope is 223Fr with a half-life of 22 minutes.