Search results
Results From The WOW.Com Content Network
Europium is a chemical element; it has symbol Eu and atomic number 63. It is a silvery-white metal of the lanthanide series that reacts readily with air to form a dark oxide coating. Europium is the most chemically reactive, least dense, and softest of the lanthanides. It is soft enough to be cut with a knife.
Rare-earth element abundances of basalts, of both terrestrial and lunar origins [1]. The europium anomaly is the phenomenon whereby the europium (Eu) concentration in a mineral is either enriched or depleted relative to some standard, commonly a chondrite or mid-ocean ridge basalt (MORB).
Pages in category "Europium" The following 3 pages are in this category, out of 3 total. ... This page was last edited on 23 October 2017, at 18:56 (UTC).
This page is not an article, and the only criterion for inclusion is consensus that an article fits on this page. Lists of unusual things in Wikipedia mainspace (see Category:Lists of things considered unusual ) should have an external reference for each entry that specifically classifies it as unusual, to avoid making it a point of view (POV ...
Europium compounds fluoresce under UV light at 395 nm and 365 nm. [1] Europium compounds are compounds formed by the lanthanide metal europium (Eu). In these compounds, europium generally exhibits the +3 oxidation state, such as EuCl 3, Eu(NO 3) 3 and Eu(CH 3 COO) 3. Compounds with europium in the +2 oxidation state are also known.
Naturally occurring europium (63 Eu) is composed of two isotopes, 151 Eu and 153 Eu, with 153 Eu being the most abundant (52.2% natural abundance).While 153 Eu is observationally stable (theoretically can undergo alpha decay with half-life over 5.5×10 17 years), 151 Eu was found in 2007 to be unstable and undergo alpha decay. [4]
James Madison (1751–1836) was a Founding Father of the United States and its fourth president, serving from March 4, 1809, to March 4, 1817.Dubbed the "Father of the Constitution" for his role in creating the U.S. Constitution, he had been dissatisfied with the weak government under the Articles of Confederation, and helped organize the Constitutional Convention of 1787.
Europium is exempt of this classification as it has two valence states: Eu 2+ and Eu 3+. [29] Yttrium is grouped as heavy rare-earth element due to chemical similarities. [30] The break between the two groups is sometimes put elsewhere, such as between elements 63 (europium) and 64 (gadolinium). [31]