Ytterbium, Yb, Atomic number 70

General

Ytterbium [ʏtɛrbiʊm] is a chemical element with the element symbol Yb and atomic number 70. In the periodic table it is in the group of lanthanides and is thus also one of the rare earth metals. Ytterbium is after the first locality, the pit Ytterby near Stockholm, named, as well as yttrium, Terbium and erbium.
Ytterbium (derived from Ytterby, a pit on an island north of Stockholm archipelago, the same for the names of the elements yttrium, Terbium and erbium was the inspiration) was 1878 discovered by the Swiss chemist Jean Charles de Marignac Galissard. Marignac found in the earth known as Erbia a new element and named it Ytterbia. He suspected him of the isolated compound is a new element, he called ytterbium. 1907 separated by the French chemist Georges Urbain Marignacs Ytterbia into two components, Neoytterbia and Lutetia. Carl Auer von Welsbach worked at the same time also with Ytterbia and called the two components and aldebaranium Cassiopeium. Later, they shortened the name element to Neoytterbium ytterbium. The pure metal was 1937 by Klemm and Bonner shown by the reduction of YbF 3 with potassium. The determination of the physical and chemical properties of the element ytterbium could only 1953 after production of the pure metal.

Extraction

After an extensive separation of the other Ytterbiumbegleiter the oxide with lanthanum to ytterbium metal is reduced. Subsequently, the ytterbium removed by sublimation.

Special features

The silver-white lustrous metal is very soft and stretchy. It forms three allotropic modifications with transformation points at -13 ° C and 795 ° C. At room temperature forms a β-ytterbium from face-centered cubic lattice, at higher temperatures, a body-centered cubic lattice. At a pressure of 16.000 bar shows β-Yb semiconductor properties in terms of electrical conductivity.
In dry air is gray in ytterbium. At higher temperatures, it burns Yb2O3 the sesquioxide. With water it reacts slowly with evolution of hydrogen to hydroxide. In mineral acids it dissolves with the formation of hydrogen on. In its compounds it is usually in the oxidation state +3 before, the Yb3 ions in water to form colorless solutions, Yb2 cations green solutions.

Use

Ytterbium may be used for grain refining and improving the mechanical properties of stainless steels. The radioactive isotope 169Yb (Half-life 32 Days) is isolated as a γ-ray source used in nuclear medicine.
Ytterbium-cobalt-iron-manganese alloys are particularly suitable for high-quality permanent magnets.
Ytterbiumdotierte crystals (mainly Yb:YAG) be used as a reinforcing material in lasers.
Ytterbium is less toxic. Metal dusts are fire- and potentially dangerous.

General
Name, Symbol

Atomic number

Ytterbium, Yb, 70
Series Lanthanides
group, Period, Block The, 6, f
Appearance silvery white
CAS-Nummer 7440-64-4
Mass fraction of element 2,5 ppm
Atomic
Atomic mass 173,04 you
Atomradius 175 pm
Kovalenter Radius 187 pm
Elektronenkonf. [Car] 4f(14) 6s2
1. Ionization 603,4 KJ / mol
2. Ionization 1174,8 KJ / mol
3. Ionization 2417 KJ / mol
Physically
Physical State fixed
Crystal structure face-centered cubic
Density 6,973 g/cm3 (25 ° C)
Magnetism paramagnetisch (χm = 3,4 * 10(-5))
Melting point 1097 K (824 C)
Boiling point 1469 K 1196 C)
Molar Volume 24,84 * 10(-6)m(3)/mol
Heat of vaporization 160 KJ / mol
Schmelzwärme 7,7 KJ / mol
Electrical conductivity 4,0*10(6) A/(V * m)
Thermal conductivity 39 W /(m*K)
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