Atomic Element Z = 5 • Metalloid
Boron (B) — Atomic Data, Electron Shells & Reactions
Boron (symbol B, atomic number 5) has a standard atomic weight of 10.81 u and ground-state configuration [He] 2s2 2p1.
Atomic Number (Z)
5
IUPAC Symbol
B
Standard Atomic Weight
10.81 g/mol
Period / Group / Block
2 / 13 / p-block
Condensed Electron Config
[He] 2s2 2p1
Full Subshell Config
1s2 2s2 2p1
Principal Shell Occupancy
[2, 3]
Pauling Electronegativity
2.04
First Ionization Energy
801 kJ/mol
Covalent Radius
84 pm
Melting Point
2349 K (2075.85 °C)
Boiling Point
4200 K (3926.85 °C)
Density
2.34 g/cm³
Oxidation States
+3
B (Z=5) — Valence shell highlighted in vermilion