Boron

Document v1 · published by Koskamo · updated 2026-10-04

Boron (B) is chemical element 5, a metalloid in group 13, period 2 (PubChem).

Atomic number: 5
Symbol: B
Group: 13
Period: 2
Atomic mass: 10.81 u
Electron configuration: [He]2s2 2p1
Electronegativity (Pauling scale): 2.04
Atomic radius (van der Waals): 192 pm
Ionization energy: 8.298 eV
Electron affinity: 0.277 eV
Oxidation states: +3
Standard state: Solid
Melting point: 2348 K
Boiling point: 4273 K
Density: 2.37 g/cm³
Chemical group: Metalloid
Year discovered: 1808

Source and provenance

Original source: pubchem.ncbi.nlm.nih.gov
Published on Koskamo by: Koskamo
Citation version: Document v1
Reuse: PubChem periodic table data (NIH/NLM, pubchem.ncbi.nlm.nih.gov/ptable); group and period from Jefferson Lab via PubChem

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Version history

Published by Koskamo2026-10-04
Version 1