Beryllium

characteristics
lithium - beryllium - boron


mg

[He] 2s 2
9
4

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generally
name, symbol, ordinal number beryllium, 4
series of alkaline earth metals
group, Period, block 2 (IIA), 2, s
appearance white-grey metallically
proportion at the Earth's shell 5 · 10 -4 %
atomically
atomic mass 9.01218
atomic radius 112 pm
Kovalenter radius 90 pm
Van that Waals radius -
Elektronenkonfiguration [He] 2 s 2
electrons per energy level 2, 2
electron affinity 5.0 eV
1. Ionization energy 899.5 kJ/mol
2. Ionization energy 1757.1 kJ/mol
3. Ionization energy 14848.7 kJ/mol
physically
state of aggregation firmly
modifications -
crystal structure hexagonally
density (Mohshärte) 1848 kg/m 3 (5,5)
magnetism dia.-magnetically
melting point 1551.15 K (1.278 °C)
boiling point 3243.15 K (positive pressure)
approx. 2750 K (2,476, 85 °C)
molecular volume 4,85 · 10 -6 m 3 /mol
heat of vaporization 292.40 kJ/mol
heat of fusion 12.20 kJ/mol
steam pressure 4180 Pa
speed of sound 13000 m/s
specific thermal capacity 1825 J/kg · K
electrical conductivity 31,3 · 10 6 S /m
heat conductivity 201 W/m · K
chemically
oxidation conditions of 2
oxides (basicity) BeO (more amphoter)
Normalpotenzial -1.85 V (2+ + 2e - →)
Elektronegativität 1.57 (Pauling scale)
isotopes
isotope NH t 1/2 ZM CPU M eV ZP
7 {syn.} 53,12 days ε 0.862 7 left
8 {syn.} 6,722 · 10,-17 s 0,092 -
9 100% is stable with 5 neutrons
10 in traces 1,51 · 10 6 A β - 0.556 10 B
11 {syn.} 13.81 s β - 11.506 11 B
NMR characteristics
9
nuclear spin 3/2
gamma 3,759 · 10 7 rad/T
sensitivity 0.0139
Larmorfrequenz with B = 4.7 T 28.1 M cycles per second
as far as possible and common, are used SI-UNITs.
If not differently notes,
the indicated data apply with standard conditions.

Beryllium is a chemical element in the periodic system of the elements with the symbol and the ordinal number 4. The bivalent, steal-grey light alloy is very hard and brittle. It is usually used as alloying addition.

Table of contents

history

beryllium (of griech. βηρυλλος = beryl, a jewel, which contains beryllium) was represented to 1798 by Louis Nicolas Vauquelin in form of its oxide from the jewels beryl and emerald. 1828 succeeded to Friedrich better and Antoine Bussy the reduction of the beryllium chloride with potassium to the metallic beryllium.
Because ofthe sweet taste of the beryllium salts respectable. Beryllium oxide was used in France until 1957 for the fourth element the designation Glucinium.

After other versions the word becomes beryllium from the Indian word beryl, which is enough from the peninsula Arabia or Indiaadmits was derived. Gem stones with beryllium portions in this area are well-known for more than 400 years.

In the antiquity and the Middle Ages transparent pieces of beryl served often as charm glass. From the word beryl is derived also the expression eyeglasses (glases from beryl).

[] If occurrences

work on

the element beryllium, is in particular as BeO 1797 of L. N. Vauquelin discovered. The rare element occurs in 30 different minerals . The most important are Bertrandit (the USA) and beryl (China, Russia and Brazil). The most beautifuland most valuable are the jewels aquamarine, emerald, red beryl, Euklas, Gadolinit, Chrysoberyll, Phenakit, Chrysoberyll and alexandrite. Beryllium ore stores are in the equatorial belt. Earlier stores were north to foot of the high Tauern over Bramberg in Austria. In the USA niedrighaltige stores are diminished from BeO ore in the Nevada desert. The production of the highly pure, metallic beryllium takes place via a aufwändige electrolysis. Becomes predominant by a chemo+thermal reduction of beryllium fluoride, in addition, assistance of Fluor andSulfur, with magnesium beryllium hydroxide respectable. Beryllium oxide and finally beryllium metal won.

Attachment 2 + mg → MgF 2 +.

Beryllium is used in the technology mainly as alloying element with copper, copper cobalt and nickel (CuBe, CuCoBe and NiBe). Beryllium oxide becomes because ofits high heat conductivity and its electric insulation in electronics uses.

characteristics

Beryllium
beryllium

beryllium possesses for a light alloy a remarkably high melting point. Apart from the very high thermal capacity it possesses a modulus of elasticity than steel, higher around 1/3, the oscillation damping is likewise very high. Additionally it possesses a high permeability for X-ray. Alpha particles set neutrons free from beryllium .

<math> {} ^ {9} _4 \ mathrm + {} ^ {4} _2 \ mathrm He^ {2+} \ tons {} ^ {12} _6 \ mathrm C + {} ^ {1} _0 \ mathrm n </math>

At ambient temperatureberyllium at dry air is steady, it forms a passivating oxide film, which resists the attack of concentrated nitric acid. In hydrochloric acid it is fast attacked. At damp air it becomes encrusted with a layer from hydroxide.

use

Semi-finished material and blanks made of beryllium metal are often manufactured powder metallurgy, in HIP and CIP procedures. (Hot-isostatic pressing/cold-ISO-static pressing.) you are to be regarded as sinter product. Cast parts from beryllium do not find technical use to other characteristics, like Grobkörnigkeit, because of the anisotropischen characteristics and.Processes for the production of beryllium metal and for the alloyage with copper and/or nickel use beryllium hydroxide and beryllium oxide as basic material. It concerns with the production from beryllium and beryllium oxide the BeO haltigem ore a thermochemical reduction.

<math> \ mathrm {\, ^9Be+ n \ rightarrow 2 \, \, ^4He + 2 \, n - 1.57 \, MeV}< /math>
  • because of its permeability for X-ray as beryllium windows in x-ray tubes.
  • Cover and soil made of beryllium metal for the measurement of gamma-rays in the universe of the European Cos b satellite.
  • Beryllium becomes predominant the productionby Kontakt-und feather/spring materials from beryllium bronzes the technical Berylliumhaltige copper alloys are used. They are characterised by high hardness, elasticity, fatigue strength, corrosion resistance, Nichtmagnetisierbarkeit as well as electrical and thermal conductivity .

The outstanding characteristics of beryllium metal make it because of its highPrice and its toxicity only for few applications suitably.

Further applications:

  • Relay contacts from CuBe and CuCo.
  • the beryllium metal catch mirror (70 kg heavily) of the 4 8-Meter of Spiegelteleskope of the Very Large Telescope (VLT) at the Paranal in Chile, as well as the catch mirror of the Pencil sharpener space telescope are from verspiegeltem beryllium.
  • Clock feathers/springs from iron - nickel - beryllium, NiBe.
  • CuBe and CuCoBe electrodes for the stop welding and for plastic spraying nozzles.
  • Brake disks of the space shuttle (small weight and high thermal capacity) made of beryllium metal.
  • Rotors in gyroscope compasses, mobile mirrorsin optical systems, drive systems in tape decks
  • neutron source: Irradiation with alpha particles produces free neutrons
  • nickel beryllium alloys for temperature-loaded liaison vehicles, like thermostat switches.
  • Nickel beryllium of tools, because of anti-sticking inclination for secondary Bor-Silikat-Gläser and optical Mehrfocalglaslinsen.
  • Beryllium oxide as heat conducting insulator for high frequency power transistors, - Zirkulatoren and - high load resistances. Because of thatGiftigkeit is replaced BeO increasingly by alumina.
  • High toner of High ending loudspeakers by way of trial made of beryllium metal of YAMAHA. (Kalotten diaphragm for ultra deep tones)
  • McLaren Mercedes used this material in the formula 1 with the engine construction.
There the team in the year 1998 and 1999 almost, this material was competitionless after a protest by Ferrari was forbidden. As reason they called that the material is during processing injurious to health.

safety references

beryllium, beryllium oxide and beryllium salts are poisonous and krebserregend. Beryllium can to skin-, Lungs -, spleen - and liver damage lead. Beryllium accumulates in the human body and leads after latency for many years to the formation of tumors. First of all inhaliertes beryllium, it is dangerous leads to the Berylliose. Swallowed beryllium is relativeharmless, since it is predominantly again separated.

Beryllium enriches itself in the tobacco and arrives when smoking into air (a coincidence investigation in the institute for Max-Planck for metal research in Stuttgart). Also in tomato plants, as in the tobacco, traces were proven by beryllium. Inthe act: Beryllium is often in the earth's surface and thus is not very unusual this. In badly ventilated areas concentrations were proven with the machine cutting by beryllium above the maximum job concentration. Exhaust and isolating with the splinter acceptance are absolutely necessarily.

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