Beryllium

4 lithium ← beryllium → boron - ↑ Be ↓ Mg periodic table
General
Name, Symbol, Number	beryllium, Be, 4
Chemical series	alkaline earth metals
Group, Period, Block	2, 2, s
Appearance	white-gray metallic
Atomic mass	9.012182(3) g/mol
Electron configuration	1s2 2s2
Electrons per shell	2, 2
Physical properties
Phase	solid
Density (near r.t.)	1.85 g/cm³
Liquid density at m.p.	1.690 g/cm³
Melting point	1560 K (1287 °C, 2349 °F)
Boiling point	2742 K (2469 °C, 4476 °F)
Heat of fusion	7.895 kJ/mol
Heat of vaporization	297 kJ/mol
Heat capacity	(25 °C) 16.443 J/(mol·K)
Vapor pressure P/Pa 1 10 100 1 k 10 k 100 k at T/K 1462 1608 1791 2023 2327 2742
Atomic properties
Crystal structure	hexagonal
Oxidation states	2 (amphoteric oxide)
Electronegativity	1.57 (Pauling scale)
Ionization energies (more)	1st: 899.5 kJ/mol
	2nd: 1757.1 kJ/mol
	3rd: 14848.7 kJ/mol
Atomic radius	105 pm
Atomic radius (calc.)	112 pm
Covalent radius	90 pm
Miscellaneous
Magnetic ordering	diamagnetic
Electrical resistivity	(20 °C) 35.6 nΩ·m
Thermal conductivity	(300 K) 200 W/(m·K)
Thermal expansion	(25 °C) 11.3 µm/(m·K)
Speed of sound (thin rod)	(r.t.) 12870 m/s
Speed of sound (thin rod)	(r.t.) 287 m/s
Shear modulus	132 GPa
Bulk modulus	130 GPa
Poisson ratio	0.032
Mohs hardness	5.5
Vickers hardness	1670 MPa
Brinell hardness	600 MPa
CAS registry number	7440-41-7
Notable isotopes
Main article: Isotopes of beryllium iso NA half-life DM DE (MeV) DP 7Be syn 53.12 d ε - 7Li γ 0.477 - 9Be 100% Be is stable with 5 neutrons 10Be trace 1.51×106 y β- 0.556 10B

Beryllium (chemical symbol Be, atomic number 4) ranks among the lightest of all known metals. Steel-gray in color, it is strong but brittle and is classified as an alkaline earth metal.

• A bivalent element
• primarily used as a hardening agent in alloys (most notably beryllium copper).

7777777777

From USGS: "Beryllium (Be) is one of the lightest of all metals and has one of the highest melting points of any light metal. Beryllium metal is used principally in aerospace and defense applications because of its stiffness, light weight, and dimensional stability over a wide temperature range. Beryllium-copper alloys are used in a wide variety of applications because of their electrical and thermal conductivity, high strength and hardness, good corrosion and fatigue resistance, and nonmagnetic properties. Beryllium oxide is an excellent heat conductor, with high strength and hardness, and acts as an electrical insulator in some applications. The United States, one of only three countries that process beryllium ores and concentrates into beryllium products, supplies most of the rest of the world with these products."

7777777777 Applications:

• Beryllium-copper alloys have a wide variety of applications, including the manufacture of spot-welding electrodes, springs, non-sparking tools, and electrical contacts. These applications are based on several properties of the alloys: their ability to absorb large amounts of heat, good electrical and thermal conductivity, high strength and hardness, nonmagnetic properties, and good resistance to corrosion and fatigue.
• Beryllium alloys are also used by the defense and aerospace industries in the production of lightweight structural materials for high-speed aircraft, missiles, space vehicles, and communication satellites.
• Thin sheets of beryllium foil are used with X-ray detection diagnostics, as the foil can filter out visible light and allow only X rays to pass through.
• In the field of X-ray lithography, beryllium is used for the reproduction of microscopic integrated circuits.
• In the telecommunications industry, beryllium is made into tools that can be safely used for tuning the highly magnetic klystrons (specialized vacuum tubes) employed in high-power microwave transmissions.
• The nuclear power industry uses this metal in nuclear reactors as a neutron reflector and moderator.
• Beryllium is used in nuclear weapons for similar reasons. For example, the critical mass of a plutonium sphere is significantly reduced if the plutonium is surrounded by a beryllium shell.
• Beryllium is sometimes used in neutron sources, in which the beryllium is mixed with an alpha emitter such as ²¹⁰Po, ²²⁶Ra, ²³⁹Pu, or ²⁴¹Am.
• Beryllium is also used in making gyroscopes, various computer components, watch springs, and instruments, where lightweight materials with rigidity and dimensional stability are needed.
• Beryllium is being used in the Joint European Torus fusion research facility, to condition the plasma-facing components.
• Beryllium oxide is useful for applications that require an excellent heat conductor and electrical insulator, with a very high melting point and high strength and hardness.

77777777777

Occurrence

Beryllium ore.

Beryllium is a significant constituent of about 100 minerals. The most important of these are beryl (Al₂Be₃Si₆O₁₈), bertrandite (Be₄Si₂O₇(OH)₂), chrysoberyl (Al₂BeO₄), and phenakite (Be₂SiO₄). Precious forms of beryl are aquamarine and emerald.

The main commercial sources of beryllium and its compounds are beryl and bertrandite. Beryllium metal did not become readily available until 1957. Currently, the chief method of production is by reducing beryllium fluoride with magnesium metal. The chemical reaction can be written in terms of the following equation.

BeF₂ + Mg → MgF₂ + Be

Etymology and Discovery

The name beryllium comes from the Greek word beryllos, for "beryl." That, in turn, can be traced back to the Prakrit veruliya, from Pāli veuriya. These words appear akin to the Tamil veliru or vilar, meaning "to whiten, become pale." At one time, beryllium was referred to as glucinium (from the Greek word glykys, meaning "sweet"), based on the sweet taste of its salts.

Beryllium was discovered by Louis Vauquelin in 1798, as the oxide in beryl and emeralds. In 1828, Friedrich Wöhler and Antoine Bussy independently isolated the metal by reacting potassium with beryllium chloride.

Notable characteristics

Beryllium is a member of the family of alkaline earth metals and lies at the top of group 2 (former group 2A) of the periodic table, just above magnesium. In addition, it is situated in period 2, between lithium and boron. Among the light metals, beryllium has one of the highest melting points. Its modulus of elasticity (a measure of its elasticity) is approximately one-third more than that of steel. It is nonmagnetic and an excellent conductor of heat. The speed of sound in beryllium is about 12,500 meters per second—greater than that through any other element. Highly permeable to X rays, it liberates neutrons when struck by alpha particles.

Beryllium resists attack by concentrated nitric acid. In addition, at standard temperature and pressure (0°C, 100 kPa), it resists oxidation when exposed to air. It appears, however, that its ability to scratch glass may be due to the formation of a thin layer of its oxide.

Isotopes

Beryllium has 10 isotopes, of which only ⁹Be is stable. The isotope ¹⁰Be is produced in the atmosphere by the impact of cosmic rays on oxygen and nitrogen. This beryllium (being soluble in water at pH below 5.5) readily dissolves in rainwater (which generally has a pH less than 5) and is transported to the Earth's surface. As this water quickly becomes more alkaline, ¹⁰Be drops out of solution and accumulates at the soil surface. Based on its long half-life of 1.51 million years, ¹⁰Be has a long residence time, before it decays to ¹⁰B (an isotope of boron).

The isotope ¹⁰Be and its daughter products have been used to examine soil erosion, soil formation from regolith, and the development of lateritic soils. It has also been used to check variations in solar activity and the age of ice cores.

The instability of the isotopes ⁷Be and ⁸Be has profound consequences for cosmological theory. It means that elements heavier than beryllium could not be produced by nuclear fusion at the time of the Big Bang. Moreover, the nuclear energy levels of ⁸Be are such that carbon can be produced within stars, thus making it possible for the eventual development of living organisms.

The shortest-lived isotope of beryllium is ¹³Be, which has a half-life of 2.7 × 10^-21 seconds and decays through neutron emission. The isotope ⁶Be also is also very short-lived, with a half-life of 5.0 × 10^-21 seconds.

Applications

A square beryllium foil mounted in a steel case is ready to be used as a window between a vacuum chamber and an X-ray microscope. Beryllium filters out visible light but is highly transparent to X rays.

• Beryllium-copper alloys have a wide variety of applications, including the manufacture of spot-welding electrodes, springs, non-sparking tools, and electrical contacts. These applications are based on several properties of the alloys: their ability to absorb large amounts of heat, good electrical and thermal conductivity, high strength and hardness, nonmagnetic properties, and good resistance to corrosion and fatigue.
• Beryllium alloys are also used by the defense and aerospace industries in the production of lightweight structural materials for high-speed aircraft, missiles, space vehicles, and communication satellites.
• Thin sheets of beryllium foil are used with X-ray detection diagnostics, as the foil can filter out visible light and allow only X rays to pass through.
• In the field of X-ray lithography, beryllium is used for the reproduction of microscopic integrated circuits.
• In the telecommunications industry, beryllium is made into tools that can be safely used for tuning the highly magnetic klystrons (specialized vacuum tubes) employed in high-power microwave transmissions.
• The nuclear power industry uses this metal in nuclear reactors as a neutron reflector and moderator.
• Beryllium is used in nuclear weapons for similar reasons. For example, the critical mass of a plutonium sphere is significantly reduced if the plutonium is surrounded by a beryllium shell.
• Beryllium is sometimes used in neutron sources, in which the beryllium is mixed with an alpha emitter such as ²¹⁰Po, ²²⁶Ra, ²³⁹Pu, or ²⁴¹Am.
• Beryllium is also used in making gyroscopes, various computer components, watch springs, and instruments, where lightweight materials with rigidity and dimensional stability are needed.
• Beryllium is being used in the Joint European Torus fusion research facility, to condition the plasma-facing components.
• Beryllium oxide is useful for applications that require an excellent heat conductor and electrical insulator, with a very high melting point and high strength and hardness.

Health effects

Beryllium, its alloys, and its salts are toxic, and one should especially avoid inhaling their dust and fumes. Exposure to these materials can lead to two types of conditions: acute beryllium disease (acute berylliosis) and chronic beryllium disease (chronic berylliosis). In addition, long-term exposure can increase the risk of developing lung cancer.

An acute condition is that which develops after a short, heavy exposure and lasts for no more than a year. Depending on the type of exposure, acute beryllium disease may involve inflammation of the skin (contact dermatitis), nose and throat (nasopharyngitis), windpipe (tracheobronchitis), or lungs (pneumonitis).

Chronic beryllium disease develops after prolonged (months or years) of exposure to beryllium. The time lapse between first exposure and symptoms of the disease may be as much as 10 to 15 years. The chronic disease affects mainly the lungs but its effects may also be seen in other organs. The condition produces lesions and granulomas (tissue masses) mainly in the lungs, but it may also affect other organs, such as the skin, liver, kidney, heart, bone, lymphatic system, and nervous system. Symptoms of the chronic disease include coughing, chest pain, and breathing difficulties.

Acute chemical pneumonitis was first reported in Europe in 1933 and in the United States in 1943. Cases of chronic berylliosis were first described in 1946 among workers in plants manufacturing fluorescent lamps in Massachusetts, and the use of beryllium compounds in fluorescent lighting tubes was discontinued in 1949. The potential for exposure to beryllium exists in the nuclear and aerospace industries, the refining of beryllium metal, melting of beryllium-containing alloys, the manufacture of electronic devices, and the handling of other beryllium-containing materials.

Early researchers tasted beryllium and its various compounds for sweetness, to verify its presence. Modern diagnostic equipment no longer necessitates this highly risky procedure, and no attempt should be made to ingest this substance. Beryllium and its compounds should be handled with great care, and special precautions must be taken when carrying out any activity that may involve the release of beryllium dust. No attempt should be made to work with beryllium before familiarization with correct handling procedures.

A successful test for beryllium on different surface areas has been recently developed. This technique, in which beryllium is bound to a fluorescent chemical (sulfonated hydroxybenzoquinoline), enables the detection of beryllium at concentrations up to 10 times below the recommended limit for the workplace.

Industrial release limits

Typical levels of beryllium that industries may release into the air are on the order of 0.01 micrograms per cubic meter (µg/m³), averaged over a 30-day period, or 2 µg/m³ of workroom air for an 8-hour work shift. The current U.S. Occupational Safety and Health Administration (OSHA) permissible exposure limit for beryllium is 2 µg/m³, but this figure has been challenged as inadequate for protecting workers from developing beryllium sensitization and CBD. The American Conference of Governmental Industrial Hygienists (ACGIH), an independent organization of experts in the field of occupational health, has proposed a threshold limit value (TLV) of 0.05 µg/m³, in a 2006 Notice of Intended Change (NIC). As it can be difficult to control industrial exposures to beryllium, it is advisable to use any methods possible to reduce airborne and surface contamination by beryllium, to minimize the use of beryllium and beryllium-containing alloys whenever possible, and to educate people about the potential hazards if they are likely to encounter beryllium dust or fumes.

See also

• Chemical element
• Periodic table

References

ISBN links support NWE through referral fees

• Los Alamos National Laboratory – Beryllium

• USGS: Beryllium Statistics and Information

• Canadian Centre for Occupational Health and Safety: Beryllium Disease

• Burrell, AK. Ehler, DS. McClesky, TM. Minogue, EM. Taylor, TP. Development of a New Fluorescence Method for the Detection of Beryllium on Surfaces. Journal of ASTM International (JAI). 2005. Vol 2: Issue 9. http://www.astm.org/cgi-bin/SoftCart.exe/JOURNALS/JAI/PAGES/JAI13168.htm?E+mystore

• Infante PF, Newman LS. Commentary: Beryllium exposure and Chronic Beryllium Disease. Lancet 2004; 415-16.

• Newman LS. Beryllium. Chemical & Engineering News, 2003; 36:38.

• Kelleher PC, Martyny JW, Mroz MM, Maier LA, Ruttenber JA, Young DA, Newman LS. Beryllium particulate exposure and disease relations in a beryllium machining plant. J Occup Environ Med 2001; 43:238-249.

• Mroz MM, Balkissoon R, Newman LS. Beryllium. In: Bingham E, Cohrssen B, Powell C (eds.) Patty’s Toxicology, Fifth Edition. New York: John Wiley & Sons 2001, 177-220.

• Beryllium and Compounds: TLV® Chemical Substances Draft Documentation, Notice of Intended Change ACGIH® Publication #7NIC-042

External links

• Computational Chemistry Wiki
• It's Elemental – Beryllium
• National Pollutant Inventory - Beryllium and compounds
• WebElements.com – Beryllium

Credits

New World Encyclopedia writers and editors rewrote and completed the Wikipedia article in accordance with New World Encyclopedia standards. This article abides by terms of the Creative Commons CC-by-sa 3.0 License (CC-by-sa), which may be used and disseminated with proper attribution. Credit is due under the terms of this license that can reference both the New World Encyclopedia contributors and the selfless volunteer contributors of the Wikimedia Foundation. To cite this article click here for a list of acceptable citing formats.The history of earlier contributions by wikipedians is accessible to researchers here:

• Beryllium  ^history

The history of this article since it was imported to New World Encyclopedia:

• History of "Beryllium"

Note: Some restrictions may apply to use of individual images which are separately licensed.