| Name | erbium |
|---|---|
| Symbol | Er |
| Atomic Weight | 167.259 |
| Atomic Number | 68 |
| CAS ID | 7440-52-0 |
| Group Number | (none) |
| Group Name | Lanthanoid |
| Period Number | 6 |
| Origin of Name | Named after Ytterby, Sweden. |
| Year Discovered | 1842 |
| Discovery Credits | Discovered by C. G. Mosander at Stockholm, Sweden. |
| Class | Metallic |
| Color | Silvery white |
| Standard State | Solid at 77 F & 298 K |
| Description | Silver-gray metal of the rare earth group. slowly tarnishes
in air, slowly reacts with water, dissolves in acids. Used in infrared
absorbing glass, alloys with titanium. Diagnostic tests: |