87
Fr
223
Francium
Element 87 · 223 u · s-block
alkali metal
The most unstable of the first 101 elements. Extremely rare and radioactive — at most 30g exists on Earth at any time.
Phase (STP)
Solid
Melting Point
27 °C
Boiling Point
677 °C
Density
1.87 g/cm³
Electronegativity
0.7
Atomic Radius
—
Ionization Energy
380 kJ/mol
Electron Affinity
47 kJ/mol
Discovered
1939 · Marguerite Perey
Electron Configuration
[Rn] 7s1
Electron Orbitals
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