Francium

Alkali metal · 223.01973 u · group 1, period 7

Francium · Fr

Atomic number87

SymbolFr

CategoryAlkali metal

Standard stateSolid

Group · Period · Block1 · 7 · s

Electron configuration[Rn]7s1

Atomic mass223.01973 u

Atomic radius348 pm

Protons / Neutrons / Electrons87 / 136 / 87

Shells (e⁻ per shell)2, 8, 18, 32, 18, 8, 1

Electronegativity (Pauling)0.7

Ionization energy3.9 eV

Electron affinity0.47 eV

Oxidation states+1

Melting point300 K · 26.9 °C

Boiling point—

Density—

Year discovered1939

CPK color

#420066

State at room temp (25 °C)

solid

Position