Boron |
| Symbol | B |
|---|---|
| Latin name | Borum |
| Atomic number | 5 |
| Period | 2 |
| Element category | Metalloids |
| Relative atomic mass | 10.811 |
| Group | III.A |
| Electronegativity | 2.0 |
| Oxidation numbers | 3 |
| Electron configuration | 1s2 2s2 2p1 |
| Density [g/cm3] | 2.34 |
| State | Solid |
| Melting point [°C] | 2300 |
| Boiling point [°C] | 2550 |
| Atomic radius [pm] | 87 |
| Covalent radius [pm] | 82 |
| Thermal conductivity [W m-1K-1] | 27 |
| Heat capacity [J K-1g-1] | 1.026 |
| Discovery | 1808 |
| Hardness [Mohs scale] | 9.3 |
| Vickers hardness [MPa] | 4.9 · 104 |
| Electrical conductivity [S m-1] | 5 · 10-6 |
| 1.st ionization energy [eV] | 8.298 |
| 2.nd ionization energy [eV] | 25.154 |
| 3.rd ionization energy [eV] | 37.93 |
| Stable isotopes | 2 |
| Unstable isotopes | 4 |