Boron (element)

Boron (element)
James L Marshall · CC BY-SA 3.0 · source
Name	Boron
Atomic mass	10.81
Group	13
Appearance	brown-black metalloid
Phase	solid
Electron config	1s2 2s2 2p1
Density	2.34 g/cm3
Melting point	2349 K
Boiling point	4200 K

Boron (element)

Boron is a chemical element with atomic number 5 and symbol B, classified as a metalloid situated between Lithium and Carbon in the periodic table. It has unique electronic structure and bonding that produce complex solid forms, making it important to technologies associated with Nuclear reactor, Semiconductor, Aerospace and Glass manufacturing. Boron's chemistry links to historical discoveries, industrial extraction, and roles in agriculture, health, and materials science.

Introduction

Boron occupies Group 13 of the Periodic table and is the lightest element of its group, bridging properties of Metalloid behavior analogous to Silicon, Aluminium, and contrasts with Beryllium and Boron compounds central to inorganic chemistry. Its small atomic radius and three valence electrons produce electron-deficient bonding that leads to multicenter bonds, clusters, and icosahedral networks observed in minerals and synthetic solids. As a strategic raw material, boron-containing minerals have driven economic development in regions such as California, Turkey, and Kyrgyzstan where deposits and mining operations are concentrated.

Characteristics

Boron exhibits polymorphism with allotropes including amorphous boron and crystalline forms like beta-rhombohedral and alpha-rhombohedral; these structures underpin properties exploited by Materials science, Ceramic engineering, and Chemical engineering. Electronegativities and bonding lead to semiconducting behavior relevant to Doping (semiconductor), thermoelectric materials investigated at institutions like Bell Laboratories and IBM Research. Mechanical hardness approaches that of Boron carbide and Diamond in specialized composites used by Defense Advanced Research Projects Agency and aerospace contractors such as Boeing and Lockheed Martin. Thermal stability and neutron-absorption cross-sections tie boron to Nuclear reactor control rods and radiation shielding projects at facilities like Oak Ridge National Laboratory and Los Alamos National Laboratory.

History

Early recognition of boron traces occurred in ancient Egypt and Antiquity materials that used borates, then more clearly in 18th-century European chemistry during analyses by scientists working in Paris and London. Isolated elemental boron was first produced in impure forms by researchers linked to French Academy of Sciences and later refined with methods developed by chemists at University of Göttingen and laboratories in Germany and Russia. Industrial-scale extraction emerged in the 19th and 20th centuries with companies like Eti Maden and multinational firms expanding borate mining and processing that influenced trade agreements and industrial policy in regions such as California's Mojave Desert and Borat, Turkey-adjacent areas.

Occurrence and production

Boron occurs naturally in borate minerals including Borax, Colemanite, Tincal, and Ulexite concentrated in evaporite deposits and playa lakes associated with geological settings like the Basin and Range Province and Central Anatolian Plateau. Major producers include state entities and corporations operating in Turkey, United States, Chile, and Argentina, with extraction linked to mining companies and commodity markets overseen by bodies akin to International Trade Administration and commodity analysts from World Bank and United Nations Conference on Trade and Development. Industrial production involves refining from borate ores to boric acid and boron oxide via processes developed in chemical plants and laboratories at industrial sites in Bolu and Furnace Creek-region operations.

Applications

Boron and boron compounds are integral to industries and technologies: borosilicate glass used by Corning Incorporated for laboratoryware and cookware, boron fibers and boron nitride in high-temperature components for Aerospace firms, boron carbide armor for Military vehicles, and boron-based neutron absorbers in nuclear power plants operated by utilities such as EDF and Tokyo Electric Power Company. Agricultural use of borates as micronutrients ties to programs run by FAO and agricultural extensions at University of California. In electronics, boron doping of silicon is foundational for companies like Intel and TSMC in transistor manufacturing. Boron-containing pharmaceuticals and antiseptics have been developed and studied at institutions including NIH and pharmaceutical firms like GlaxoSmithKline.

Compounds and chemistry

Boron forms a wide range of compounds such as boranes, borates, borides, and boron halides; subjects of study in academic departments at Massachusetts Institute of Technology, University of Oxford, and ETH Zurich. Boranes (e.g., diborane) exhibit multicenter two-electron bonds studied by chemists like those associated historically with Royal Society meetings. Borates contribute to glass network formers in Corning glass products and optical materials for Laser components. Borides provide hard, refractory phases used by manufacturers like Carpenter Technology and Sandvik. Organoboron chemistry, advanced by Nobel-associated research groups and textbooks, underpins reactions such as hydroboration used in syntheses by pharmaceutical companies and academic labs at Harvard University and University of Cambridge.

Biological role and toxicity

Boron is an essential micronutrient for plants, influencing cell wall structure and development studied by botanists at Royal Botanic Gardens, Kew and agricultural researchers at Iowa State University. In animals and humans, boron's role is less well-defined; nutritional studies and toxicology research are conducted by agencies like European Food Safety Authority and US Food and Drug Administration. Excessive exposure to borates can cause reproductive and developmental effects observed in animal studies referenced by regulatory assessments, while controlled use in plant fertilizers and micronutrient supplements is promoted by agricultural extension services in regions like California and Anatolia.

Category:Chemical elements