Erbium (Er)
Erbium
Erbium (Er) is a lanthanide in period 6. Its relative atomic mass is 167.26 and the molar mass of the atom is 167.26 g/mol.
Atomic number 68
Atomic mass 167.26
Molar mass 167.26 g/mol
Category Lanthanide Solid
Properties of erbium
| Atomic number | 68 |
|---|---|
| Symbol | Er |
| Latin name | Erbium |
| Relative atomic mass | 167.26 |
| Molar mass | 167.26 g/mol |
| Group, period, block | —, 6, f |
| Category | Lanthanide |
| State at 20 °C | Solid |
| Electron configuration | [Xe] 4f¹² 6s² |
| Electronegativity (Pauling) | 1.24 |
| Atomic radius | 175 pm |
Electron configuration of erbium
Electrons per shell
K2L8M18N30O8P2
Full notation
1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 4f¹² 5s² 5p⁶ 6s²
Noble-gas notation
68 protons · 68 electrons[Xe] 4f¹² 6s²
Formula and compounds of erbium
Simple substanceErerbiumMolar mass of Er: 167.26 g/mol
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Frequently asked questions
The relative atomic mass of erbium is 167.26, so the molar mass of the atom is 167.26 g/mol.
Full: 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 4f¹² 5s² 5p⁶ 6s². Noble-gas notation: [Xe] 4f¹² 6s².