Beryllium is the chemical element with the symbol Be and atomic number 4. A bivalent element, beryllium is found naturally only combined with other elements in minerals. Notable gemstones which contain beryllium include beryl (aquamarine, emerald) and chrysoberyl. The free element is a steel-gray, strong, lightweight brittle alkaline metal. Structurally, beryllium's has very low density (1.85 times that of water), high melting point (1278 °C), high temperature stability, and low coefficient of thermal expansion. Because of its relatively high transparency to X-rays and other ionizing radiation types, beryllium also has a number of uses as filters and windows for radiation and particle physics experiments. Commercial use of beryllium metal presents technical challenges due to the toxicity (especially by inhalation) of beryllium-containing dusts. Beryllium produces a direct corrosive effect to tissue, and can cause a chronic life-threatening allergic disease called berylliosis in susceptible persons.The element is not known to be necessary or useful for either plant or animal.
Beryllium has exceptional flexural rigidity (Young's modulus 287 GPa). The modulus of elasticity of beryllium is approximately 50% greater than that of steel. The combination of this modulus plus beryllium's relatively low density gives it an unusually fast sound conduction speed at standard conditions (about 12.9 km/s). Other significant properties are the high values for specific heat (1925 J·kg−1·K−1) and thermal conductivity (216 W·m−1·K−1), which make beryllium the metal with the best heat dissipation characteristics per unit weight. In combination with the relatively low coefficient of linear thermal expansion (11.4 × 10−6 K−1), these characteristics ensure that beryllium demonstrates a unique degree of dimensional stability under conditions of thermal loading. At standard temperature and pressures beryllium resists oxidation when exposed to air (its ability to scratch glass is due to the formation of a thin layer of the hard oxide BeO). It resists corrosion by concentrated nitric acid.
The base value of each unit of ranges between 5 and 15 Ð per unit, with up to 3 units being found at any one time.
Presence on Mars: Common
|Group 1 | Group 2 | Group 3 | Group 4 | Group 5 | Group 6|
|Group 1|||Aluminum | Arsenic | Beryllium | Boron | Calcium | Cantite | Carbon | Chlorine | Chromium | Cobalt | Copper | Flourine | Helium| | Hydrogen | Iron | Lithium | Magnesium | Manganese | Nickel | Oxygen | Phosphorus | Plesium | Potassium | Silicon | Sodium||