# Boro

| Boron |
| --- |
| **5B** |
|

|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| - ↑ **B** ↓ Al |

|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
|

|  |  |  |
| --- | --- | --- |
|  |  |  |
|  |  |  |  |  |  |  |  |  |
|  |  |  |  |  |  |  |  |  |
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |

Periodic table |

 |  |
|  | beryllium ← **boron** → carbon |

 |
| Panagway |
| black-brown  |
| Kinatibuk-ang mga kinaiya |
| Ngalan, simbolo, kaiphan | boron, B, 5 |
| Paglitok | /ˈbɔərɒn/ |
| Kategoriyang elemento | metalloid |
| Group, period, block | 13, 2, p |
| Gibug-aton sa atomo | 10.81(1) |
| Kontorno sa elektron | [He] 2s2 2p1 2, 3
Electron shells of boron (2, 3) |
| History |
| Pagkadiskobre | Joseph Louis Gay-Lussac and Louis Jacques Thénard   (30 June 1808)  |
| First isolation | Humphry Davy   (9 July 1808)  |
| Physical properties |
| Phase | magahi |
| Liquid density at m.p. | 2.08 g·cm−3 |
| Melting point | 2349 K, 2076 °C, 3769 °F |
| Boiling point | 4200 K, 3927 °C, 7101 °F |
| Heat of fusion | 50.2 kJ·mol−1 |
| Heat of vaporization | 480 kJ·mol−1 |
| Molar heat capacity | 11.087 J·mol−1·K−1 |
| Vapor pressure |
|

|  |  |  |  |  |  |  |
| --- | --- | --- | --- | --- | --- | --- |
| P (Pa) | 1 | 10 | 100 | 1 k | 10 k | 100 k |
| at T (K) | 2348 | 2562 | 2822 | 3141 | 3545 | 4072 |

 |
| Atomic properties |
| Oxidation states | **3**, 2, 1 (mildly acidic oxide) |
| Electronegativity | 2.04 (Pauling scale) |
| Ionization energies (more) | 1st: 800.6 kJ·mol−1 |
| 2nd: 2427.1 kJ·mol−1 |
| 3rd: 3659.7 kJ·mol−1 |
| Atomic radius | 90 pm |
| Covalent radius | 84±3 pm |
| Van der Waals radius | 192 pm |
| Miscellanea |
| Crystal structure | rhombohedral
 |
| Magnetic ordering | diamagnetic |
| Electrical resistivity | (20 °C) ~106 Ω·m |
| Thermal conductivity | 27.4 W·m−1·K−1 |
| Thermal expansion | (25 °C) (β form) 5–7 µm·m−1·K−1 |
| Speed of sound (thin rod) | (20 °C) 16,200 m·s−1 |
| Mohs hardness | ~9.5 |
| CAS registry number | 7440-42-8 |
| Most stable isotopes |
| Main article: Isotopes of boron |
|

| iso | NA | half-life | DM | DE (MeV) | DP |
| --- | --- | --- | --- | --- | --- |
| 10B | 19.9(7)%\* | 10B is stable with 5 neutrons |
| 11B | 80.1(7)%\* | 11B is stable with 6 neutrons |
| \*Boron-10 content may be as low as 19.1% and as high as 20.3% in natural samples. Boron-11 is the remainder in such cases. |

 |
| * v
* t
* e
 |

Ang **boro** (Iningles *boron*) mao ang elementong kimiko sa talaang peryodiko nga may simbolo nga **B** ug kaiphan nga atomik 5. Ang boro mao ang metalloid.

## Ang mga gi basihan niini

## Galeriya sa hulagway

*
*
*
*
*
*