Europium
Symbol: Eu
Atomic Number: 63
Atomic Mass: 151.964 amu (atomic mass units)
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: 63
Number of Electrons: 63
Number of Neutrons: 89
Classification: Rare Earth Metal
Crustal Structure: Cubic
Density @293K: 5.259 grams per cubic centimeter
Color: Silver
The element europium is a rare earth metal belonging to the lanthanide or lanthanoid series of the periodic table. It was discovered by the French chemist Eugene-Antole Demarcay. He first suspected its existence when he found a contaminant in some samples of another rare earth element, samarium, in 1896. Demarcay eventually managed to prepare a fairly pure sample of europium metal in 1901. The element was named after the continent of Europe.
Europium is the most reactive of all the naturally occurring rare earth elements. It will react with water in a manner similar to the element calcium.
There are two naturally occurring stable isotopes of europium. In order of abundance these isotopes are europium-153 (52.19%) and europium-151 (47.81%). There have been a number of unstable isotopes of europium discovered. These unstable isotopes have mass numbers ranging from 131 to 167. Europium-131 has the shortest half-life of the unstable isotopes at 17.8 milliseconds; it decays by either proton emission or electron capture. The isotope europium-154 has the longest half-life at 8.593 years; it decays by either beta emission or electron capture
Europium metal has never been found free in nature but it can be found in mineral ores along with many other rare earth elements. Like some other rare earth elements europium is primarily produced by the ion exchange and solvent extraction processes from monazite sand or the mineral ore bastnasite. In addition to many of the rare earth elements monazite sand also contains the highly radioactive element thorium so the appropriate safety measures must be taken during the metal extraction process from this source
There are very few industrial uses for pure europium metal but it has been used to dope some plastics for use in the field of laser technology. As the element europium is good at absorbing neutrons is may have a future usage in the nuclear power industry, this application is currently being studied.
It is the compound europium oxide (Eu2O3) that has the most important commercial applications. Europium oxide is used as a phosphor to provide the red color in some television sets. It is also used as an activator for the yttrium based phosphors, yttrium oxide and yttrium orthovanadate, which are also used to provide a red color in television sets.
