Erbium (Er)
Erbium (Er) is element 68, a lanthanide. Atomic mass 167.259, configuration [Xe] 4f¹² 6s². Properties, isotopes, oxidation states, uses and history, with an interactive 3D atom model.
Key facts
| Atomic number | 68 |
|---|---|
| Symbol | Er |
| Standard atomic weight | 167.259(3) |
| Category | Lanthanide |
| Period | 6 |
| State at room temperature | Solid |
| Electron configuration | [Xe] 4f¹² 6s² |
| Valence electrons | 2 (Variable) |
| Common oxidation states | +3 |
| Common ions | No common ions |
| Electronegativity (Pauling) | 1.24 |
| First ionization energy | 589 kJ/mol |
| Atomic radius | 175 pm |
| Density | 9.07 g/cm³ |
| Melting point | 1522°C |
| Boiling point | 2868°C |
| Specific heat | 0.168 J/(g·°C) |
Natural isotopes
- Er-162: Stable
- Er-164: Stable
- Er-166: Stable
- Er-167: Stable
- Er-168: Stable
- Er-170: Stable
Common uses
- EDFA (Erbium-Doped Fiber Amplifiers)
- Dermatology lasers
- Pink glass coloring
Where it matters
- Telecommunications (Fiber optic signal amplifiers)
Hazards
- Low toxicity
History
| Discovered | 1843 |
|---|---|
| Discovered by | Carl Gustaf Mosander |
| Name | From Ytterby, Sweden |