Europium

Symbol: Eu
Atomic number: 63
Category: lanthanides
Group: n/a
Period: 6
Block: f
Atomic weight: 151.964 g/mol
Electrons per shell: 2, 8, 18, 25, 8, 2
CAS number: 7440-12-2
Phase: solid
Density: 5.264 kg/dm³ (near room temperature)
Melting point: 1099 K (826 °C, 1519 °F)
Boiling point: 1802 K (1529 °C, 2784 °F)
Crystal structure: simple cubic (body centered)
Oxidation states: 3, 2
Electronegativity: 1.2 (Pauling scale)
Name's origin: Europe
Name's meaning: the continent
Facts:
- is the most reactive of the rare earth elements; it rapidly oxidizes in air, and resembles calcium in its reaction with water
- ignites in air at about 150 °C to 180 °C
- is about as hard as lead and quite ductile
- is a metal and becomes a superconductor under pressure 80 GPa at temperature 1.8 K
- has been used to dope some types of glass to make lasers, as well as for screening for Down syndrome and some other genetic diseases
- due to its amazing ability to absorb neutrons, it is also being studied for use in nuclear reactors
- europium oxide (Eu2O3) is widely used as a red phosphor in television sets and fluorescent lamps, and as an activator for yttrium-based phosphors
- is never found in nature as a free element; however, there are many minerals containing europium, with the most important sources being bastnäsite and monazite
- the metal dust presents a fire and explosion hazard
- has no known biological function