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Boron
Metalloids · Group 13 · Period 2
Atomic properties
| Atomic number | 5 |
|---|---|
| Symbol | B |
| Standard atomic weight | 10.81 |
| Classification | Metalloids |
| Group | 13 |
| Period | 2 |
| Block | p-block |
| Electron configuration | [He] 2s2 2p1 |
| Electronegativity (Pauling) | 2.04 |
| Common oxidation states | +3 |
Physical properties
| Phase at 20 °C | Solid |
|---|---|
| Density | 2.34 g/cm³ |
| Melting point | 2076 °C |
| Boiling point | 3927 °C |
| Discovered | 1808 |
| CAS number | — |