68 Er 167.26
Erbium
Lanthanide
Erbium (Er) is a chemical element with atomic number 68, classified as a lanthanide. At room temperature it is a solid. It was discovered in 1843 by Carl Gustaf Mosander.
Properties
- Atomic number
- 68
- Atomic mass
- 167.26 u
- Category
- Lanthanide
- Group
- 0
- Period
- 6
- Block
- f-block
- Electron configuration
- [Xe] 4f¹² 6s²
- Phase at STP
- Solid
- Density
- 9.066 g/cm³
- Melting point
- 1802 K (1528.8 °C)
- Boiling point
- 3141 K (2867.8 °C)
- Electronegativity
- 1.24
- Atomic radius
- 226 pm
- Ionization energy
- 6.108 eV
- Discovery
- 1843 · Carl Gustaf Mosander
Common uses
Fiber optic cables, lasers, nuclear technology, photography
Did you know?
Essential for internet fiber optic communications worldwide.
Experiment with the elements
Erbium doesn't form any compounds in our lab yet, but the periodic table sandbox lets you combine dozens of other real elements into real compounds — water, table salt, ammonia and many more — with their true chemical formulas.