Europium is a chemical element with the symbol Eu and atomic number 63.
Europium is a silvery-white metal of the lanthanide series that reacts readily with air to form a dark oxide coating.
It is the most chemically reactive, least dense, and softest of the lanthanide elements.
It is soft enough to be cut with a knife.
Europium was isolated in 1901 and named after the continent of Europe.
Europium usually assumes the oxidation state +3, like other members of the lanthanide series, but compounds having oxidation state +2 are also common.
All europium compounds with oxidation state +2 are slightly reducing.
Europium has no significant biological role and is relatively non-toxic compared to other heavy metals.
Most applications of europium exploit the phosphorescence of europium compounds.
Europium is one of the rarest of the rare-earth elements on Earth.
Characteristics
Physical properties
Europium is a ductile metal with a hardness similar to that of lead.