Beryllium
A poisonous element that helped a physicist win a Nobel Prize
This element is not very abundant in the universe and only forms in supernova explosions.
Beryllium’s occurrence
The name “beryllium” came from the name of the mineral beryl (beryllium aluminum cyclosilicate, Be₃Al₂Si₆O₁₈). In its turn, beryl gets its name from the town of Belur in Southern India, near Madras. Since ancient times, this region was known for its emerald deposits — various types of beryl. Sometimes large crystals of this mineral are found here, some over 20 feet (6 meters) in length. It is also found in the USA, Brazil, Russia, India and Madagascar. The Romans and ancient Egyptians highly valued emeralds and beryls, and the Roman philosopher and writer Pliny the Elder, who wrote in the 1st century CE, believed that they were both formed from the same mineral.
How beryllium was discovered
Owing to the sweet taste of beryllium compounds dissolved in water, the element was initially named “glucine” (from Ancient Greek γλυκύς, glukos – sweet). The element was discovered in 1798 by the French chemist Louis-Nicolas Vauquelin, who called it glucinum. The element got received modern name at the suggestion of the chemists Klaproth and Ekeberg. Major work on establishing the composition of compounds of beryllium and its minerals was carried out by the Russian chemist Ivan Avdeev (1818—1865). He proved that beryllium oxide had the composition BeO, and not Be₂O₃, as was believed previously. In free form, beryllium was isolated in 1828 by the French chemist Bussy, and the German chemist Wöhler, independently of him. Pure metallic beryllium was obtained in 1898 by the French chemist Lebeau using electrolysis of molten salts.
Beryllium’s toxicity
There is no data about the biological role of beryllium, but it is toxic for humans. Breathing in the fumes of beryllium causes chronic damage to the lungs, known as berylliosis: coughing, difficult and shallow breathing, pains in the chest, weight loss, and possible damage to the eyes and skin. People working with beryllium alloy in the mid-20th century faced serious risks when fluorescent lamps were coated with phosphorus, which contained beryllium oxide. The manufacture of these lamps was ended when a large number of workers in the USA were found to have lung disease.
Main properties and application areas of beryllium
Beryllium is a light, strong, brittle, silvery-white metal, resistant to corrosion, and which melts at a very high temperature. All of these properties make beryllium ideal for use in spacecraft and missiles. Additionally, a beryllium hydride is used as a component of rocket fuels. Beryllium oxide is the most thermally conductive of all oxides, and its thermal conductivity at room temperature is higher than the majority of metals and almost all non-metals (apart from diamond and silicon carbide), so it can be used for the manufacture of highly thermally conductive high-temperature insulators and fire-proof materials.
An alloy of copper containing a small percentage of beryllium makes a non-sparking, highly durable alloy, which is ideal for the manufacture of barrels for oil and flammable liquids, when one spark may cause a catastrophe.
In laser technology, beryllium aluminate is used for making solid-state emitters (rods, plates). Beryllium is unusual for its ability to reflect neutrons, so it is used in the manufacture of nuclear weapons. Inside the warhead, neutrons bombard uranium to release energy. As the neutrons are reflected off the case containing beryllium, this leads to an acceleration of the nuclear reaction inside the warhead.
Beryllium’s role in science
Beryllium played a key role in the development of atomic theory, when neutrons were discovered. In the early 20th century, physicists measuring atomic masses theorized that nuclei must not only contain positively charged protons. The British physicist Sir James Chadwick conducted a 10-year study of the atom, and in 1932 reported that if beryllium was bombarded with alpha particles given off radium, it would radiate unknown subatomic particles. These particles had approximately the same mass as protons, but did not have an electrical charge. Chadwick discovered the neutron, and in 1935 won the Nobel Prize for physics for his discovery.
