Boron (B)


Boron is one of the simplest of atoms. The only simpler ones are hydrogen, helium, lithium and beryllium. Boron has chemical symbol B, atomic number 5, and occurs naturally as 80% B11 and 20% B10. The latter isotope has a high cross section for thermal neutron absorption, 3800 barns. Thermal neutron counters are often filled with BF3 gas. The gamma ray from the neutron capture reaction B10(n,-)B11* followed by decay of the B11* to an α plus Li7 produces ionization which is then detected. Boron is also used in reactor control rods. This is a nuclear property of boron, and has nothing at all to do with its chemistry. The atomic weight of boron is 10.81.

Boron is found in a variety of similar minerals all related to borax, sodium tetraborate, Na2B4O7·10H2O. The name comes from the Arabic buraq, "white." Borax is the same in French and German as in English, but the element is bor. In Spanish, the words are bóraxo and boro. It is a relatively rare element in the earth's crust, representing only 0.001%. In the United States, borax is found in large amounts in California, in Searles Lake brines and in the Mojave desert. It is also found in Turkey, South America and other places. The natural deposits are dried-up lake beds. Molten borax reacts with metal oxides to form borates that dissolve in the melt, so it is useful as a welding and soldering flux, and in colored enamels for iron. In fact, this was the earliest use of borax, as a pottery glaze. This same property is used for borax bead tests in chemistry, where the characteristic colors produced in a transparent borax drop melted on a loop of platinum wire in a bunsen burner flame are observed. Blue, for example, is the color of cobalt; green, of chromium. The color can differ in oxidizing (blue) and reducing (yellow) flames.



Oral doses greater than 100 mg/day may cause: dermatitis, diarrhea, disturbances in digestion, lethargy, nausea, vomiting. Ingesting Boron-containing preparations have resulted in dryness of the skin and digestive upsets, but low dose supplements have shown no toxic effect yet. Best taken with manganese, calcium and Vitamin B2 (remember you need Vitamin B6 with Vitamin B2).
