5 - Boron metalloid
Discovered by Joseph Gay-Lussac in 1808
- 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.
| Shell | Electrons | Orbitals |
|---|---|---|
| 1 | 2 | 2 in 1s |
| 2 | 3 | 2 in 2s + 1 in 2p |
10.81 u
Atomic Mass
1.2 Å
Atomic Radius
4200 K
Boiling Point
0.84 Å
Covalent Radius
2.08 g/cm³
Density
26.99
Electron Affinity
2.04
Electronegativity
8.3 eV
First Ionization Energy
2573.15 K
Melting Point
2
Number of Shells
3
Electron Valency
5
Atomic Number
2, 3
Electron Shell Occupations
1.03 J/(g K)
Specific Heat
