| General |
|---|
| Name | Boron | | Symbol | B | | Number | 5 | | Chemical series | Metalloids | | Group / Period | 13 / 2 | | Block | p-block | | CAS registry number | 7440-42-8 |
| Physical properties |
|---|
| State | solid | | Density | 2.34 g/cm3 | | Melting point | 2349 K (2076 °C, 3769 °F) | | Boiling point | 4200 K (3927 °C, 7101 °F) | | Critical point | |
| Atomic properties |
|---|
| Atomic Weight | 10.811 g/mol | | Crystal structure | rhombohedral | | Electronegativity | 2.04 | | Atomic radius | 85 pm | | Atomic radius (calculated) | 87 pm | | Electron configuration | [He] 2s2 2p1 | | Electrons per shell | 2, 3 | | Number of protons | 5 | | Number of neutrons | 6 |
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Carbon