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4
Be
9.0122
Beryllium
Alkaline earth metals · Group 2 · Period 2
Atomic properties
| Atomic number | 4 |
|---|---|
| Symbol | Be |
| Standard atomic weight | 9.0122 |
| Classification | Alkaline earth metals |
| Group | 2 |
| Period | 2 |
| Block | s-block |
| Electron configuration | [He] 2s2 |
| Electronegativity (Pauling) | 1.57 |
| Common oxidation states | +2 |
Physical properties
| Phase at 20 °C | Solid |
|---|---|
| Density | 1.85 g/cm³ |
| Melting point | 1287 °C |
| Boiling point | 2469 °C |
| Discovered | 1798 |
| CAS number | — |