Chemical Formula: Eu
Present as: cation
Europium is a chemical element with symbol Eu and atomic number 63. It is a moderately hard, silvery metal which readily oxidizes in air and water. Europium usually assumes the oxidation state +3, but the oxidation state +2 is also common. All europium compounds with oxidation state +2 are slightly reducing. Most applications of europium exploit the phosphorescence of europium compounds. Europium is one of the least abundant elements in the universe; only about 5×10−8% of all matter in the universe is europium.
Europium is a ductile metal with a hardness similar to that of lead. It crystallizes in a body-centered cubic lattice. Europium is relatively non toxic compared to other heavy metals. It is quite rare, has no biological role and few commercial uses.