5 B
Metalloid
Boron
Found in borax; used in glass.
Properties of Boron
- Atomic number (Z)
- 5
- Symbol
- B
- Atomic mass
- 10.81 g/mol
- Category
- Metalloid
- Group
- 13
- Period
- 2
- Electron configuration
- [He] 2s² 2p¹
- Electronegativity (Pauling)
- 2.04
- Atomic radius
- 87 pm
- First ionization energy
- 801 kJ/mol
- Melting point
- 2349 K (2075.8 °C)
- Boiling point
- 4200 K (3926.8 °C)
- Density
- 2.34 g/cm³
- Phase at 25 °C
- Solid
- Discovered
- Discovered in 1808