出典:Wikipedia
出典:『Wikipedia』 (2011/07/03 19:06 UTC 版)
Europium ( /jʊˈroʊpiəm/ ew-roh-pee-əm) is a chemical element with the symbol Eu and atomic number 63, which was named after the continent of Europe. It is a moderately hard silvery metal which readily oxidizes in air and water. Being a typical member of the lanthanide series, europium usually assumes the oxidation state +3; however, europium compounds with the oxidation state +2 are also common, and all of them are slightly reducing. Europium has no significant biological role and is relatively non-toxic compared to other heavy metals.