- Atomic Radius (Å)
Boron is a metalloid chemical element with symbol B and atomic number 5. Produced entirely by cosmic ray spallation and supernovae and not by stellar nucleosynthesis, it is a low-abundance element in both the Solar system and the Earth's crust. Boron is concentrated on Earth by the water-solubility of its more common naturally occurring compounds, the borate minerals.
5
Atomic Number
10.81 u
Atomic Mass
2573.15 K
Melting Point
4200 K
Boiling Point
2.08 g/cm³
Density
1.2 Å
Atomic Radius
0.84 Å
Covalent Radius
2.04
Electronegativity
8.3 eV
First Ionization Energy
26.99
Electron Affinity
2
Number of Shells
3
Electron Valency
2, 3
Electron Shell Occupations
1.03 J/g
Specific Heat