NO. 005Metalloid

B

Boron

Boron is a metalloid essential for plant growth and used in borosilicate glass.

Crystal Structure

Rhombohedral

Atomic Mass10.81 u

Density2.34 g/cm³

Melting Point2349 K

Boiling Point4200 K

Atomic Radius87 pm

Electronegativity2.04

Ionization Energy801 kJ/mol

Electron Affinity27 kJ/mol

Bonding TypeCovalent

Oxidation States3

Acid/BaseAcidic

ReactivityMedium

Electron Configuration

[He] 2s2 2p1

Discovered ByJoseph Louis Gay-Lussac

Year1808

Known Isotopes

Boron-10Boron-11