europium oxide

Europium oxide, fluorescing red under an ultraviolet light. Image copyright: smart-elements.com.

Europium (Eu) is a silver-white, metallic element of the lanthanide series, being the softest and most volatile member. It was first isolated as the oxide in 1896; the element itself was discovered by E. A. Demarçay in Paris in 1901 . Its chief ores are monazite and bastnaesite. Europium is used in the manufacture of color television screens, lasers, thin superconducting alloys, and control rods in nuclear reactors. Its most common isotope is 153Eu (52.18%).

atomic number 63
relative atomic mass 151.96
relative density 5.25
melting point 822°C (1,512°F)
boiling point 1,597°C (2,907°F)