Europium

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Basic Information

 * Name:** Europium **Symbol:** Eu **Atomic Number:** 63 **Atomic Mass:** 151.964 amu **Melting Point:** 822.0 °C (1095.15 K, 1511.6 °F) **Boiling Point:** 1597.0 °C (1870.15 K, 2906.6 °F) **Number of Protons/Electrons:** 63 **Number of Neutrons:** 89 **Classification:** Rare Earth **Crystal Structure:** Cubic **Density @ 293 K:** 5.259 g/cm3 **Color:** silver

Atomic Structure

 * [[image:http://www.chemicalelements.com/bohr/b0063.gif]] ||  || **Number of Energy Levels:** 6
 * First Energy Level:** **Second Energy Level:** **Third Energy Level:** **Fourth Energy Level:** **Fifth Energy Level:** **Sixth Energy Level:** ||

Isotopes

 * ** Isotope ** || ** Half Life ** ||
 * Eu-147 || 24.4 days ||
 * Eu-148 || 54.5 days ||
 * Eu-149 || 93.1 days ||
 * Eu-150 || 36.0 years ||
 * Eu-151 || Stable ||
 * Eu-152 || 13.5 years ||
 * Eu-152m || 9.3 hours ||
 * Eu-153 || Stable ||
 * Eu-154 || 8.6 years ||
 * Eu-155 || 7.4 years ||
 * Eu-156 || 15.2 days ||

Facts

 * Date of Discovery:** 1901 **Discoverer:** Eugene Demarcay **Name Origin:** Europe **Uses:** color televisions **Obtained From:** Man-made

History: Europium was first found by Paul Emile Lecoq de Boisbaudran in 1890.

Brief description: europium ignites in air at about 150 to 180°C. Europium is about as hard as lead and is quite ductile. It is the most reactive of the rare earth metals, quickly oxidising in air. It resembles calcium in its reaction with water. It is used in television screens to produce a red colour.

Isolation: uropium metal is available commercially so it is not normally necessary to make it in the laboratory, which is just as well as it is difficult to isolate as the pure metal. This is largely because of the way it is found in nature. The lanthanoids are found in nature in a number of minerals. The most important are xenotime, monazite, and bastnaesite. The first two are orthophosphate minerals LnPO4 (Ln deonotes a mixture of all the lanthanoids except promethium which is vanishingly rare) and the third is a fluoride carbonate LnCO3F. Lanthanoids with even atomic numbers are more common. The most comon lanthanoids in these minerals are, in order, cerium, lanthanum, neodymium, and praseodymium. Monazite also contains thorium and ytrrium which makes handling difficult since thorium and its decomposition products are radioactive. For many purposes it is not particularly necessary to separate the metals, but if separation into individual metals is required, the process is complex. Initially, the metals are extracted as salts from the ores by extraction with sulphuric acid (H2SO4), hydrochloric acid (HCl), and sodium hydroxide (NaOH). Modern purification techniques for these lanthanoid salt mixtures are ingenious and involve selective complexation techniques, solvent extractions, and ion exchange chromatography. Pure europium is available through the electrolysis of a mixture of molten EuCl3 and NaCl (or CaCl2) in a graphite cell which acts as cathode using graphite as anode. The other product is chlorine gas.

fission product yields of europium isotopes are low near the top of the mass range for fission products. Like other lanthanides, many isotopes, especially isotopes with odd mass numbers and neutron-poor isotopes like 152Eu, have high cross sections for neutron capture, often high enough to be neutron poisons. 151Eu is the beta decay product of samarium-151, but since this has a long decay half-life and short mean time to neutron absorption, most 151Sm instead ends up as 152Sm. 152Eu (half-life 13.516 years) and 154Eu (half-life 8.593 years) cannot be beta decay products because 152Sm and 154Sm are non-radioactive, but 154Eu is the only long-lived "shielded" nuclide, other than 134Cs, to have a fission yield of more than 2.5 parts per million fissions.[|[][|10][|]] A larger amount of 154Eu is produced by neutron activation of a significant portion of the non-radioactive153Eu; however, much of this is further converted to 155Eu.


 * Uses**
 * europium isotopes are good neutron absorbers and are used in nuclear control applications
 * the oxide is used as a phosphor activator and europium-activated yttrium vanadate is used as the red phosphor in colour TV tubes
 * europium-doped plastic is a laser material
 * alloys
 * manufacturing fluorescent glass