Europium
Definition and meaning of Europium in chemistry.
Europium is a chemical element with the symbol Eu and atomic number 63. It is a highly reactive, soft, silvery metal and is formally recognized as the most reactive of all the rare-earth lanthanides. Europium rapidly oxidizes in air and reacts vigorously with water in a manner very similar to calcium.
In more detail
Located deep in the f-block of the periodic table, europium is remarkably unique among the lanthanides because it readily exists in both the +2 and +3 oxidation states under standard conditions. The exceptional stability of the +2 state is due entirely to its half-filled f-electron shell, which significantly influences its chemical behavior and dictates its commercial extraction methods. Because it closely resembles alkaline earth metals in its +2 state, it very often substitutes for calcium in certain natural minerals. Europium is the least dense, softest, and most chemically volatile member of the entire lanthanide series. It is extracted slowly from bastnasite and monazite, but its natural concentration within these ores is consistently very low. The single most prominent characteristic of europium compounds is their intense luminescence under ultraviolet light, emitting brilliant red or blue colors depending closely on the specific oxidation state and host crystal lattice.
Key facts
| Field | General Chemistry |
|---|---|
| Symbol | Eu |
| Atomic number | 63 |
| Atomic mass | 151.96 u |
| Category | Lanthanide |
| State at room temperature | Solid |
| Melting point | 822 °C |
| Year discovered | 1901 |
Europium is critically crucial in the high-volume manufacturing of phosphors, acting as the primary source of the vivid red color in older cathode ray tube televisions and modern LED lighting displays.
Frequently asked questions
Why is europium explicitly used in anti-counterfeiting measures?
Europium phosphors are widely used in euro banknotes because they predictably emit specific, hard-to-forge red and blue colors when exposed to specialized ultraviolet light.
How must reactive europium metal be properly stored?
Due directly to its exceptionally high reactivity with ambient oxygen and moisture, europium must be safely stored under an inert atmosphere like argon gas or submerged deeply in mineral oil.