Cobalt

of these articles treats the element cobalt. For the operating system of the same name see Palm OS.

Cobalt (also cobalt) is a chemical element.

Characteristics
iron - cobalt - nickel
CO
RH

[acre] 3d 7 4s 2
59
27
CO

< div id= " box2 "style= " boron that: solvently 1px black; position: absolute; top: 30px; left: 176px; width: 7px; height: 9px; OVERFLOW: hidden; “/>

generally
name, symbol, ordinal number cobalt, CO, 27
series of transition metals
group, period, block 9 , 4, D
appearance metallically with
a bluish gräulichen colour
atomically
atomic mass 58.93320
atomic radius (computed) 135 (152) pm
Kovalenter radius 126 pm
van the Waals radius -
Elektronenkonfiguration [acre] 3d 7 4s 2
electrons per energy level of 2, 8, 15, 2
oxidation conditions (oxides) 2, 3 (more amphoter)
crystal structure hexagonally and/or cubically
(transition temp.hcp> fcc: ~421 °C)
physically
state of aggregation firmly
point of curie: 1121 °C
density (Mohshärte) 8900 kg/m 3 (5,0)
magnetism ferrousmagnetically
melting point 1768 K (1495 ° C)
boiling point 3200 K (2927 °C)
molecular volume 6,67 · 10 -6 m 3/mol
heat of vaporization 376.5 kJ/mol
heat of fusion 16.19 kJ/mol
steam pressure 175 Pa at 1768 K
speed of sound 4720 m/s with 293,15 K
different
Elektronegativität 1.88 (Pauling scale)
electron affinity 5.0 eV
specific thermal capacity 420 j (kg · K)
Electrical conductivity 17,2 · 10 6 s /m
heat conductivity 100 w (m · K)
1. Ionization energy 760.4 kJ/mol
2. Ionization energy 1648 kJ/mol
3. Ionization energy 3232 kJ/mol
4. Ionization energy of 4950 kJ/mol
isotopes
isotope NH t 1/2 ZM CPU M eV ZP
55 CO {syn.} 17.53 h ε 3,451 55 Fe
56 CO {syn.} 77.27 D ε 4.566 56 Fe
57 CO {syn.} 271.79 D ε 0.836 57 Fe
58 CO {syn.} 70.86 D ε 2.307 58 Fe
59 CO 100% CO is stable with 32 neutrons
60CO {syn.} 5.2714 A β - 2.824 60 never
61 CO {syn.} 1.850 h β - 1.322 61 never
NMR characteristics
59 CO
nuclear spin 7/2
gamma wheel/T 6,317 · 10 7
sensitivity 0.277
Larmorfrequenz with B = 4.7 T 47.2 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.

The name cobalt is derived from Kobold , because Kobolde in earlier conception of ores with this (at that time) unbearbeitbaren mineralcontaminated.

1735 discovered the Swedish chemist Georg Brandt the up to then unknown element and gave it its name.

The symbol CO is derived from that latin designation CO baltum.

Table of contents

characteristics

cobalt is magnetically, harder and more firmly than steel and very tough. In the chemical behavior it is similarly , steady at air the iron and nickel, it from oxidizing working acids is solved.

physiology

cobalt is for the human nutrition an essential trace element as a component of Vitamin B12 (Cobalamin), which with healthy humans by the intestine bacteria directly from cobalt ions can be formed. The necessary cobalt quantity is extremely small, onlyabout 0.2 micro gram per day. While small overdoses of CO connections for humans are only little poisonous, larger overdoses (starting from approximately 25-30 Milligramm per day) lead to striking, lung, stomach illnesses, liver, heart, kidney damage and cancer ulcers. As one in Canada in former times The mortality rate enriched, rose beers for foam stabilization with cobalt with strong beer drunkards to approximately 50% on under heart myasthenia („Canadian beer drunkard heart “). Today however no more cobalt is added to the beer. (Source: Expert Group on of Vitamins and of mineral, 2002)

occurrence

cobalt is as trace element in most soils and also in numerous minerals (most accompanied by nickel, whereby nickel is four times more frequent in the earth's crust about three to). Both elements are chalkophil andcharacteristically of basic and ultrabasische Magmatite. Cobalt stores are usually polymetallisch (cu, never, AG, Fe and U), whereby cobalt is usually won only as by-product. Important cobalt ores are:Cobalt gloss (= Cobaltit; CoAsS), cobalt nickel gravel (= Linneit Siegenit, (CO, never) 3 S 4), Kobaltblüte (=Erythrin), earth cobalt (= Asbolan), feeding cobalt (=Smaltin, CoAs 3) and Heterogenit (CoOOH). Important ore stores are in Canada, Zambia, Morocco, democratic Republic of the Congo, Cuba, Russia, Australia and in the USA.

The largestPromotion nations are the democratic Republic of the Congo (24.1% world market portion in the year 2003), Zambia (22.7%), Australia (13.9%), Russia (9.7%) and Canada (8.7%).

the radioactive has applications cobalt as pure metal only few applications , Isotope 60 CO serves sterilization , preservation, etc. as gamma emitter - for cancer therapy. Its use as alloying element and in cobalt connections makes it however a strategically important metal. Main applications: as alloying constituent of superalloys, as binder phase in tungsten carbides and diamond tools,as oxide, sulfate, hydroxide or carbonate in heat-firm colors and pigments (z. B. for painting of porcelain and ceramic(s)), as a component of magnetic alloys, as acetate in Trocknern for colors and lacquers, as catalyst (desulphurisation hydrogenation),as hydroxide or lithium - Kobalt-Oxid (LiCoO 2) in batteries, in corrosion and/or verschleissfesten alloys and as trace element for medicine and agriculture.

Cobalt arises in its connections usually to two or trivalently, these connections possesses often strong colors.

Important cobalt connections:

see also

Wiktionary: Cobalt - word origin, synonyms and translations

Web on the left of

Commons: Cobalt - pictures, videos and/or audio files
 

  > German to English > de.wikipedia.org (Machine translated into English)