Thulium (Tm)
"The Portable X-Ray, the rarest of heroes, who can create X-rays on the go for mobile medical units."
A memorable persona to anchor Tm in your mind.
9.32
Grams per cm³
1545
Celsius (°C)
227
Radius (pm)
Daily Life Link
Thulium is found in a portable X-ray machine used in field hospitals.
Discovery & History
Year Discovered
1879
Discovered By
Per Teodor Cleve
Origin of Name
"The name comes from Thule, the ancient name for Scandinavia."
Technical Properties
Atomic Mass
168.934 u
Standard State
solid
Boiling Point
1950°C
Electron Configuration
[Xe] 4f136s2
1st Ionization Energy
6.184 eV
Electron Affinity
N/A
Oxidation States
"Thulium is a soft, bright, silvery-gray metal."
Did You Know?
It is the least abundant of the naturally occurring lanthanides.
Portable X-ray devices can be powered by a small piece of thulium that has been bombarded with neutrons in a nuclear reactor. The resulting radioactive isotope emits X-rays without needing a large power supply.
Despite its rarity and high cost, it has been used in lasers.
Its name comes from Thule, the Ancient Greek and Latin name for a mythical, distant land in the far north, possibly Scandinavia.