Europium
Element 63 · Lanthanide
Europium stands out among lanthanides for being the most reactive — it tarnishes rapidly and even reacts with cold water. Its chemistry is also unusual: the half-filled 4f shell makes the +2 state unusually stable, so europium(II) compounds are common.
Its fame comes from light. Europium phosphors produce the sharp red in displays and the blue in fluorescent lamps, and tiny amounts are printed on euro banknotes as an anti-counterfeiting marker that glows under ultraviolet light.
Key facts
| Atomic number | 63 |
|---|---|
| Atomic weight | 151.96 |
| Category | Lanthanide |
| Group / Period | — / 6 |
| Block | f |
| Electron configuration | 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f7 |
| Common oxidation states | +3, +2 |
| State at STP | Solid |
| Electronegativity | 1.20 |
| Density | 5.24 g/cm³ |
| Melting point | 822 °C |
| Boiling point | 1529 °C |
Occurrence
Europium occurs in monazite and bastnasite. It is one of the scarcer lanthanides, which keeps its price high relative to its neighbors.
Applications
Red and blue phosphors in displays
Anti-counterfeit markers on euro banknotes
Fluorescent and energy-saving lamps
Lasers and optical devices
Common compounds
- europium oxide
- europium chloride
- europium-doped phosphors
Europium is named after Europe, and tiny amounts of its glowing compounds are printed on euro banknotes as an anti-counterfeiting feature.
Data source: IUPAC standard atomic weights 2021