69Tm168.93
Thulium
LanthanidesRare-earth metals used in strong magnets, phone screens and lasers.
[Xe] 4f¹³ 6s²
- Atomic number
- 69
- Atomic mass
- 168.93
- Protons
- 69
- Neutrons
- 100 (most common)
- Electrons
- 69
- Shells
- 2, 8, 18, 31, 8, 2
- State at 25 °C
- Solid
- Position
- Period 6, f-block
Proton (+)Neutron (0)Electron (−)
Discovered byPer Teodor Cleve, 1879Per Teodor Cleve: 2 elements
Named after Thule, a mythical land in the far north.
Did you know?
- It is one of the rarest of the rare-earth elements.
- Its radioactive form powers small X-ray devices without electricity.
Where it's found
- Rare-earth ores
What it's used for
- Portable X-ray machines
- Lasers
Try it
There's no safe home experiment for Thulium. Explore it with the animated atom above instead.