1. General Information
- Symbol: B
- Atomic Number: 5
- Atomic Weight: 10.81
- Group: 13 (Boron Group)
- Period: 2
- Block: p-block
- Electron Configuration: [He] 2s² 2p¹
- Electrons per Shell: 2, 3
2. Physical Properties
- Phase at STP: Solid
- Melting Point: 2076°C (3769°F)
- Boiling Point: 3927°C (7101°F)
- Density: 2.34 g/cm³
- Heat of Fusion: 50.2 kJ/mol
- Heat of Vaporization: 508 kJ/mol
- Molar Heat Capacity: 11.087 J/(mol·K)
3. Chemical Properties
- Oxidation States: +3, +2, +1, -1
- Electronegativity: 2.04 (Pauling scale)
- Ionization Energies: 1st: 800.6 kJ/mol, 2nd: 2427.1 kJ/mol, 3rd: 3659.7 kJ/mol
- Covalent Radius: 84 pm
- Van der Waals Radius: 192 pm
4. Isotopes
- Boron-10: 19.9% (stable)
- Boron-11: 80.1% (stable)
- No significant radioactive isotopes
5. Applications
- Used in borosilicate glass, which is resistant to thermal shock
- Essential component in strong neodymium magnets
- Utilized in detergents, bleaches, and insecticides
- Used in the semiconductor industry for doping silicon and germanium
- Important in the production of fiberglass
- Has applications in the medical field, particularly in cancer treatment with boron neutron capture therapy (BNCT)
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