General

Boron (B) properties


Atomic mass, symbol and atomic number

boron is a naturally occurring element with the element symbol B and the atomic number 5. In the periodic table it stands with an atomic mass of 10.81 u in the 3rd main group. The chemical element discovered by Joseph Louis Gay-Lussac in 1808 is not radioactive and is in a solid state at room temperature.

Profile: Boron

General
Chemical element:boron
Symbol:B
Atomic number:5
Group:boron group
Period:2
Block:p-block
Series:semimetals
Appearance:black
explorers:Joseph Louis Gay-Lussac
Year of discovery:1808
Atomic properties
Atomic mass:10,81 u
Atomic radius:85 pm
Covalent radius:82 pm
Van der Waals radius:192 pm
Electron configuration:He 2s2 2p1
ionization:800.6 kJ / mol
Physical Properties
Physical state:firmly
Density:2,460 g / cm3
Crystal structure:rhombohedrally
Magnetism:diamagnetic
molar volume:4,39 · 10-6 m3/ mol
Mohs hardness:9,3
Melting point:2076 ° C
Boiling point:3930 ° C
Heat of fusion:50 kJ / mol
Heat of vaporization:508 kJ / mol
Thermal conductivity:27 W
Chemical properties
electronegativity:2,04

Did you know that ...

  • Boron is the second hardest element after carbon (diamond)?
  • Rocket fuel contains a certain amount of boron?
  • elemental boron practically does not occur in nature?
  • Boron is best detected by the so-called curcumin method?