boron metal or nonmetal is a chemical element with the symbol B and atomic number 5. It is an electron deficient metalloid. This means it has vacant p-orbitals and is able to form covalent bonds with highly electronegative elements such as fluorine and nitrogen. It is also able to react with highly electropositive metals such as sodium. In addition, it can form compounds with itself. It is a member of group thirteen of the periodic table.
It is found in nature primarily as borate minerals such as tincal, kernite, colexite, and borax. It is extracted industrially from these as boron oxide (B2O3) by reduction with magnesium or aluminum. Boron oxide can be purified to produce elemental boron. Boron can be combined with carbon to form boron carbide, which is extremely hard and can be used as an abrasive. It can also be combined with nitrogen to form boron nitride, which is even harder and can be used as an abrasive.
A small amount of elemental boron is added to steel alloys to make it stronger and more ductile than high-strength steel. It is also used in glass-making to create borosilicate glasses that are strong and resistant to thermal shock. It is also used in ceramics and polymers for high-strength, lightweight structural materials.
Some boron is used as a dopant in semiconductors to modify electrical conductivity. It is also used in medicine to treat a condition called osteoarthritis and as a neutron capture therapy for cancer. The human body absorbs boron mostly from dietary sources in the form of soluble salts such as boric acid. Over long periods of time boron can damage the reproductive organs of humans and animals.