PTL:Europium
From ChemEd Collaborative
| Symbol: | Eu |
|---|---|
| Atomic Number: | 63 |
| Atomic Weight: | 151.694(1) |
| Electron Configuration: | [Xe] 4f7 6s2 |
| Atomic Radius: | 204.2pm |
| Melting Point: | 822°C |
| Boiling Point: | 1596°C |
| Heat of Fusion: | 9.21kJ/mol |
| Heat of Vaporization: | 143.5kJ/mol |
| Specific Heat Capacity: | 0.18J/gK |
Europium metal is in the lanthanide series of elements, which stretches from lanthanum (La) through lutetium (Lu). Like many of these elements, it has common oxidation numbers of +2 and +3.
Contents |
Discovered
The element was discovered by Demarçay in 1896. He was examining a sample of from which samarium had only recently been isolated and suspected the existence of a new element. Only after a long and difficult separation was he able to isolate an impure sample of a new element,
Name
which he decided to call europium.
Characteristics
Eu, with an odd atomic number, is one of the least abundant of the lanthanides in earth's crust. Nonetheless, it is 20 times more abundant than silver and gold combined.
Europium resembles lead in that it is soft, shiny, and hard, but its density (5.243 g/cc) is lower than that of lead (11.35 g/cc). In the solid state, the metal has a body-centered cubic structure.
Prepared
Eu metal is obtained by reducing the oxide with powdered lanthanum in a tantalum crucible at high temperature.
Eu2O3(s) + 2 La(s) 
2 Eu(s) + La2O3(s)
Reactions
Eu is the most reactive of the lanthanides. Its reaction with water is similar to that of calcium.
3 Eu(s) + 6 H2O(liq) 2 Eu(OH)3(aq) + 3 H2(g)
and it forms an oxide, Eu2O3, on reaction with air.
Uses
It spite of its low abundance, europium oxide is widely used as a red phosphor in [color television tubes].
Emission Spectra
This is the emission spectra for Europium.
