Beryllium

I

Introduction

Beryllium, symbol Be, gray, brittle metallic element, with an atomic number of 4. It is in group 2 (or IIa) of the periodic table (see Periodic Law). Beryllium was named for its chief mineral, beryl, an aluminum beryllium silicate. It was discovered as an oxide, now known as beryllia, in 1797 by French chemist Louis Nicolas Vauquelin. The free element was first isolated in 1828 independently by Friedrich Wöhler and Antonine Alexandre Brutus Bussy. Because the soluble compounds are sweet-tasting, the new element was first called glucinium, a reference to the sugar glucose.

II

Properties and Occurrence

Beryllium, one of the alkaline earth metals, ranks about 51st in natural abundance among the elements in Earth's crust. Its atomic weight is 9.012. Beryllium melts at 1287°C (2349°F), boils at 2471°C (4480°F), and has a specific gravity of 1.85. Beryllium has a high strength per unit weight. It tarnishes only slightly in air, becoming covered with a thin layer of oxide. The ability of beryllium to scratch glass is usually ascribed to this oxide coating. Beryllium compounds are generally white (or colorless in solution) and show great similarity in chemical properties to the corresponding compounds of aluminum. This similarity makes it difficult to separate beryllium from the aluminum that is almost always present in beryllium ores.

III

Uses

The addition of beryllium to some alloys often results in products that have high heat resistance, improved corrosion resistance, greater hardness, greater insulating properties, and better casting qualities. Many parts of supersonic aircraft are made of beryllium alloys because of their lightness, stiffness, and dimensional stability. Other applications make use of the nonmagnetic and nonsparking qualities of beryllium and the ability of the metal to conduct electricity. Beryllium has important use in so-called multiplexing systems. In miniature, high-purity components made with beryllium, a single wire can carry hundreds of electronic signals.

Because X rays easily pass through pure beryllium, the element is used as window material for X-ray tubes. Beryllium and its oxide, beryllia, are also used as a moderator, or so-called blanket, around the core of a nuclear reactor because of the tendency of beryllium to slow down or capture neutrons (see Nuclear Energy).

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Although beryllium products are safe to use and handle, the fumes and dust released during fabrication are highly toxic. Extreme care must be taken to avoid breathing or ingesting even very small amounts. Specially designed exhaust hoods are used by persons working with beryllium oxide.

Beryllium and its oxide are being utilized more and more in industry. Besides its importance in aircraft and X-ray tubes, beryllium is used in computers, lasers, televisions, oceanographic instruments, and personal body armor.

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