Eu
Europium is the most reactive rare earth element, used as a red phosphor in displays.
Physical Properties
| Atomic Mass | 151.96 u |
| Density | 5.243 g/cm³ |
| Melting Point | 1099.0 K |
| Boiling Point | 1802.0 K |
| Appearance | Silvery-white metallic |
| State at Room Temp | Solid |
Chemical Properties
| Electronegativity | 1.2 (Pauling) |
| 1st Ionization Energy | 547.1 kJ/mol |
| Electron Affinity | 11.2 kJ/mol |
| Oxidation States | +2, +3 |
Atomic Properties
| Electron Configuration | [Xe] 4f7 6s2 |
| Atomic Radius | 180.0 pm |
| Covalent Radius | 198.0 pm |
| Van der Waals Radius | 233.0 pm |
Discovery
| Discovered By | Eugene-Anatole Demarcay |
| Discovery Year | 1901 |
| Location | Paris, France |
| Named After | Named after the continent of Europe |
About Europium
Europium is the most reactive of the rare earth elements, rapidly oxidizing in air. It has the lowest density among the lanthanides. Its fluorescent properties make it valuable for displays and anti-counterfeiting.
Uses & Applications
Red phosphors for displays, euro banknote anti-counterfeiting marks, and nuclear reactor control rods.
Fun Fact
Europium compounds fluoresce red under UV light and are used as anti-counterfeiting markers in euro banknotes.
Isotopes
| Mass Number | Abundance | Half-Life | Stable |
| 151 | 0.4781% | - | Yes |
| 153 | 0.5219% | - | Yes |
Electron Configuration
[Xe] 4f7 6s2