The metalloid Boron (B) is a versatile and useful element that has found many different uses in domestic and industrial processes in more advanced cultures.
Physical characteristics:
Atomic number – 5
Atomic mass – 10.811
Atomic group IIIA
Oxidation state – +3
Isotopic states – 14
Stable Isotopes – 2
Boron compounds had been in use for thousands of years but it wasn’t until 1808 that it was isolated as an element. Two French chemists, Gay-Lussac and Thnard independently announced their work at almost the same time as a British chemist working alone, Sir Humphry Davy.
In their time the only way to isolate Boron was to add boric acid to Potassium (K) in a classic direct substitution reaction. Potassium is more reactive than Boron. Today Boron is isolated by heating borax with carbon.
One of the most common interactions I have with Boron has to do with its ability to absorb neutrons.
When an element has more neutrons than its dominant, stable state it is called an isotope. The nucleus becomes unstable causing nuclear decay. Some nuclear material is ejected in the form of an alpha particle () and the atom becomes something else; most of the time it becomes Lithium.
The charged alpha particle is easily detected thus making Boron very useful in determining reactor power levels. Boron trifluoride gas (BF3) is used in virtually all neutron detectors.
Boron has a wide macroscopic cross-section for neutrons. That means it is very good at absorbing free neutrons. As a result, many materials associated with operating nuclear reactors. Each Boron atom can absorb as many as six neutrons before destabilizing.
One very public use of Boron compounds came during the Chernobyl meltdown. The cement dropped by those brave helicopter crews were heavily loaded with borated silicates. The Boron reduced the runaway reactor power below criticality. That reduced both heat and radiation levels.
A more common usage is in pyrotechnics. Boron mixed with the fuel matrix results in flares and fireworks with a green color.
There are several commercially useful compounds made with Boron. Sodium borate pentahydrate is probably the most in demand. It is used in producing fiberglass insulation.
Boric acid is still in demand as an active agent in creating textile fiberglass. This is used in manufacturing cellulose insulation and makes it fireproof.
Domestically, Boron is still heavily in use in the home in its common form; borax. It’s a laundry booster that helps soap dissolve in water. That makes it easier for soap to bond with contaminants and prevent it from redepositing on clothing.
Boron occurs naturally in much of the world’s crust (10mg/kg) and is found dissolved in seawater (4mg/l).
