Among the hardest man-made substances on Earth are some boron compounds, and only diamond is harder. This element is a very hard material and becomes even harder when reacted with carbon or nitrogen. Pure boron can be extracted from various minerals, such as ulexite and kernite. The demand for this element became so high once people moved to live in the extreme heat of Death Valley, USA, to work in the boron mines. Boron compounds in the soil are essential for healthy plant growth. We use boron in our homes every day. For example, tough, heat-resistant glassware is reinforced with boron. Boric acid, H3BO3, is a natural antiseptic. A flexible layer of boron-based glass fibers is used to stiffen thin LCD screens for televisions and laptops. Even some types of play dough and blandibu contain boron compounds. Boron is named after a crumbled white salt called borax, which is used in detergents. The element is also present in a wide range of objects, from insecticides
to tank armor.

Summary of properties (B)

Atomic weight [10.806, 10.821]
Discoverer (year) Davy, Sir Humphry & Gay-Lussac, Louis-Joseph (1808)
Natural form non-metal solid (rhombohedral)
Electron configuration [He] 2s2 2p1
Melting point (ºC) 2300
Boiling point (ºC) 2550
Abundance in earth's crust (ppm) 10
Isotope (abundance) 10B (19.9), 11B (80.1)
Density g/cm3 2.34
Van der Waals radius (pm) 192
Covalent radius (pm) 84
Electronegativity (Pauling) 2.04
Vaporization enthalpy (kJ/mol) 480.00
Enthalpy of fusion (kJ/mol) 50.20
Specific heat capacity (J/g·K) at 25ºC and 1 atm 1.03
Thermal conductivity (W/cm·K) at 25ºC and 1 atm 0.270
Oxidation state +3
Electron affinity (eV) 0.28
1st Ionization potential (eV) 8.2980

Back to the Periodic Table of the Elements.