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87
Fr
[223]
Francium
Alkali metals · Group 1 · Period 7
Atomic properties
| Atomic number | 87 |
|---|---|
| Symbol | Fr |
| Standard atomic weight | [223] |
| Classification | Alkali metals |
| Group | 1 |
| Period | 7 |
| Block | s-block |
| Electron configuration | [Rn] 7s1 |
| Electronegativity (Pauling) | 0.79 |
| Common oxidation states | +1 |
Physical properties
| Phase at 20 °C | Solid |
|---|---|
| Density | 1.87 g/cm³ |
| Melting point | 27 °C |
| Boiling point | 677 °C |
| Discovered | 1939 |
| CAS number | — |