{"id":289,"date":"2020-04-09T10:17:05","date_gmt":"2020-04-09T10:17:05","guid":{"rendered":"https:\/\/thechemicalelements.com\/?page_id=289"},"modified":"2023-08-15T13:17:57","modified_gmt":"2023-08-15T13:17:57","slug":"europium","status":"publish","type":"post","link":"https:\/\/thechemicalelements.com\/europium\/","title":{"rendered":"Europium (Eu)"},"content":{"rendered":"\n

Europium is a chemical element with an atomic number of 63 in the periodic table of elements. It\u2019s one of the least abundant rare-earth elements that can be traced in Earth\u2019s crust. Being a member of the lanthanides family of periodic table elements, europium is a divalent chemical element that makes it one of the most volatile members of the lanthanide series.\u00a0<\/span><\/p>\n\n\n\n

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Chemical and Physical Properties of Europium<\/span><\/h2>\n\n\n\n
Property<\/strong><\/td>Value<\/strong><\/td><\/tr>
Symbol<\/td>Eu<\/td><\/tr>
Atomic number<\/td>63<\/td><\/tr>
Atomic weight (mass)<\/td>151.964 g.mol-1<\/td><\/tr>
Group (number)<\/td>Lanthanides<\/td><\/tr>
Period<\/td>6<\/td><\/tr>
Color<\/td>A silvery-white metal<\/td><\/tr>
Physical state<\/td>Solid at 20\u00b0C<\/td><\/tr>
Half-life<\/td>From 1.1(5) ms [0.9(+5\u22123) ms] to 13.516 years<\/td><\/tr>
Electronegativity according to Pauling<\/td>1.2<\/td><\/tr>
Density<\/td>5.24 g \/ cm\u22123<\/td><\/tr>
Melting point<\/td>822\u00b0C, 1512\u00b0F, 1095 K<\/td><\/tr>
Boiling point<\/td>1529\u00b0C, 2784\u00b0F, 1802 K<\/td><\/tr>
Van der Waals radius<\/td>Unknown<\/td><\/tr>
Ionic radius<\/td>Unknown<\/td><\/tr>
Isotopes<\/td>9 (2 naturally occurring isotopes)<\/td><\/tr>
Most characteristic isotope<\/td>153Eu<\/td><\/tr>
Electronic shell<\/td>[Xe] 4f76s2<\/td><\/tr>
The energy of the first ionization<\/td>587.6 kJ.mol-1<\/td><\/tr>
The energy of the second ionization<\/td>1149 kJ.mol-1<\/td><\/tr>
Discovery date<\/td>In 1901 by the French chemist Eug\u00e8ne-Anatole Demar\u00e7ay<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

Located between barium<\/a> and hafnium<\/a> in the periodic system of elements, with the symbol Eu, atomic number 63, atomic mass of 151.964 g.mol<\/span>-1<\/span>, and electron configuration [Xe] 4f<\/span>7<\/span>6s<\/span>2<\/span>, europium is a soft and ductile metal that reaches its boiling point at 1529\u00b0C (2784\u00b0F, 1802 K), while the melting point is achieved at 822\u00b0C (1512\u00b0F, 1095 K). The atomic radius of an atom of europium is 198 pm (covalent radius). <\/span><\/p>\n\n\n\n

This member of the lanthanides family of elements has an electronegativity of 1.2 according to Pauling and is the most reactive lanthanide. It easily tarnishes when it comes into contact with air at room temperature, and reacts readily with H2O molecules. Namely, it readily oxidizes in contact with oxygen<\/a> from the air and forms Eu(OH)2 \u2219 H2O. This rare-earth element also burns at about 150\u00b0C to 180\u00b0C. At temperatures below 1.8K, europium displays the properties of a superconductor.\u00a0\u00a0<\/span><\/p>\n\n\n\n

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How Was Europium Discovered?<\/span><\/h2>\n\n\n\n

When the chemical element cerium<\/a> (Ce) was discovered in 1803, the scientists had not finished their work only by determining its chemical properties. Namely, this substance continued to generate new chemical elements, thus enriching the family of rare-earth elements in the periodic system.<\/span><\/p>\n\n\n\n

To begin with, the Swedish chemist Carl Mosander managed to separate lanthanum<\/a> and didymium ore (a praseodymium<\/a> and neodymium<\/a> compound) in 1839. In 1879, the Austrian chemist Carl Auer von Welsbach (Carl Auer)<\/span><\/p>\n\n\n\n

The story of the discovery of europium begins in the late 1880s. The English scientist Sir William Crookes (1832 – 1919) researched electric phosphorescence by conducting a spectroscopic analysis of a mineral sample that contained the elements ytterbium<\/a> and samarium. His measurements brought up new spectral lines in the spectra absorbed by the substance. Sir Crookes firmly believed that he\u2019s got a new chemical element in front of him, only he couldn\u2019t derive relevant evidence from his findings and isolate it. <\/span><\/p>\n\n\n\n

Several years later, the French scientist Paul-\u00c9mile Lecoq de Boisbaudran (1838 – 1912) managed to confirm the findings of Sir William Crookes after detecting the same color lines of the spectra by using the spectroscopy technique in his experiments. However, it was the French chemist Eugene-Anatole Demar\u00e7ay (1852 – 1903) who succeeded in producing a europium salt. As a spectroscopy specialist, in 1901 de Boisbaudran wrote his name among the discoverers of new chemical elements. <\/span><\/p>\n\n\n\n

Namely, by isolating the rare-earth europium metal as the <\/span>oxide europia<\/span><\/i> from the samarium-gadolinium concentrates, de Boisbaudran presented the next chemical element named europium to the world of science. Still, the pure metal form of europium was not isolated until recent years.\u00a0\u00a0<\/span><\/p>\n\n\n\n

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How Did Europium Get Its Name?<\/span><\/h2>\n\n\n\n

This rare-earth element with beautiful phosphorescence was named after the continent of Europe, thus honoring the European scientists who have paved the way to its discovery and invested all of their knowledge and experience to determine its properties. <\/span>Europa<\/span><\/i> was a Phoenician princess from Greek mythology, symbolizing the beauty of the moon. It comes from the Greek word \u0395\u1f50\u03c1\u03ce\u03c0\u03b7 (Europe), carrying the notion of “broad, wide face”.<\/span><\/p>\n\n\n\n

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Where Can You Find Europium?<\/span><\/h2>\n\n\n\n

By the means of spectroscopy, europium was identified as a trace element in the Sun and the stars. Being one of the rarest earth elements, europium can be also found in minute amounts in the rare-earth minerals and ores, such as monazite (a thorium<\/a> and yttrium mineral compound) and bastnasite (a rare earth carbonate mineral). This chemical element is also obtained from the products of nuclear fission. <\/span><\/p>\n\n\n\n

Nowadays, europium is chiefly obtained through an ion exchange process from material rich in rare-earth elements, labeled as monazite sand ((Ce, La, Th, Nd, Y) PO<\/span>4<\/span>). The process includes mixing Eu<\/span>2<\/span>O<\/span>3<\/span> with a 10%-excess of lanthanum metal and exposing the mixture to heat in a tantalum crucible under high vacuum. The pure silvery-white metal is also produced by the electrolysis of the molten chloride with sodium<\/a> chloride. <\/span><\/p>\n\n\n\n

The major mining locations of the europium producing ores are found in China and the United States.\u00a0\u00a0<\/span><\/p>\n\n\n\n

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Europium in Everyday Life<\/span><\/h2>\n\n\n\n

The phosphorescent properties of europium as its most distinguished chemical effects makes this lanthanide suitable for the following applications:<\/span><\/p>\n\n\n\n