Quick Facts
| Property | Value |
|---|---|
| Symbol | Tm |
| Atomic Number | 69 |
| Atomic Mass | 168.93 u |
| Category | Lanthanide |
| Period | 6 |
| Group | 3 |
| Block | f |
| Electron Configuration | [Xe] 4f¹³ 6s² |
History and Discovery
Discovered by: Per Teodor Cleve Year of Discovery: 1879 Location: Uppsala, Sweden
Etymology
Named after Thule, the ancient name for Scandinavia.
Applications and Uses
- Portable X-ray machines (thulium-170)
- High-temperature superconductors
- Laser materials
- Euro banknote anti-counterfeiting
- Ceramic magnetic materials
Interesting Facts
- Second rarest lanthanide (after promethium)
- Thulium-170 provides portable X-ray sources
- Named after the mythical land of Thule
- One of the most expensive rare earths
- Used in some surgical lasers