Atomic number 63
Atomic mass 167.26 g.mol -1
Density 9.2 g.cm-3 at 20°C
Melting point 1522 °C
Boiling point 2510 °C
Discovered by Carl Mosander in 1843
Europium is a soft silvery metal, both are and expensive. It is the most reactive of the lanthanide group: it tarnishes quickly in air at room temperature, burns at about 150 C to 180 C and reacts readly with water.
Europium is a neutron adsorber, , so it is used in nuclear reactors control rods. Europium phosphors are used in television tubes to give a bright red colour and as an activator for yttrium-based phosphors. For powerful street lighting a little europium is added to mercury vapour lamps to give a more natural light. A salt of europium is used for newer phosphorescent powder and paints.
Europium is one of the less abundant rare-earth elements: it is almost as abundant as tin . It is never found in nature as the free element, but there are many elements containing eruropium. Main mining areas are China and USA. Reserves of europium are estimated to be around 150.000 tonnes and world production of the pure metal is around 100 tonnes a year.
Europium has no known biological role. Europium salts could be mildly toxic by ingesiton, but its toxicity has not been fully investigated.
Europium poses no environmental threath to plants or animals. The metal dust presents a fire and explosion hazard.