CAS Number7440-08-6
PubChem CIDna
Atomic Radius168
Atomic Volume22.23
Atomic Weight[210]
Boiling Point962
Bulk Modulus
Crystal StructureSimple Cubic
Covalent Radius140
Electrical Resistivity
Electron Configuration[Xe] 4f14 5d10 6s2 6p4
Electrons per shell2, 8, 18, 32, 18, 6
Heat of Fusion13
Heat of Vaporization100
Ionization Potential8.417
Magnetic Ordering
Magnetic Susceptibility
Mass Number84
Melting Point254
Atomic Number210
Oxidation States-2, 2, 4, 6
Poisson Ratio
Shear Modulus
Specific Heat Capacity-
Thermal Conductivity0.2
Van der Waals radius
Young's Modulus
Abundance in Earth's crustna
Abundance in Universena
Po Polonium 84 (209) 16 6 p 84 254.0 962.0 [Xe] 6s2 4f14 5d10 6p4 2 8 18 32 18 6 9.32 N/A Silver Monoclinic 2.0 2.19 {"1":"812.1"} 821 183.3 176 +4,2 1.67 22.7 13.0 120.0 20.0 1 102.1 y 147.1y AlphaEmission Solid, Conductor, Metal, Radioactive, Natural, Metalloid peh-LOW-ni-em Silvery-gray, extremely rare, radioactive metal. Used in industrial equipment that eliminates static electricity caused by such processes as rolling paper, wire, and sheet metal. Occurs in pitchblende from decay of bismuth. bbr5yWwsI1o Polonium
Thulium was discovered by Swedish chemist Per Teodor Cleve in 1879 by looking for impurities in the oxides of other rare earth elements.

The first researcher to obtain nearly pure thulium was Charles James, a British expatriate working on a large scale at New Hampshire College in Durham.

High-purity thulium oxide was first offered commercially in the late 1950s. Named after Thule, the earliest name for Scandinavia 84 1898 Marie Curie France Named after "Poland" (birthplace of Marie Curie)

Isotopes of Thulium

Standard Atomic Weight


Stable Isotopes

Unstable Isotopes

188Po 189Po 190Po 191Po 192Po 193Po 194Po 195Po 196Po 197Po 198Po 199Po 200Po 201Po 202Po 203Po 204Po 205Po 206Po 207Po 208Po 209Po 210Po 211Po 212Po 213Po 214Po 215Po 216Po 217Po 218Po 219Po 220Po

Thulium is considered to be non-toxic
Thulium ore occurs most commonly in China
Thulium is used to dope yttrium aluminum garnets used in lasers.

It has also been used in high-temperature superconductors similarly to yttrium.

Thulium has use in ferrites, ceramic magnetic materials that are used in microwave equipment.

Thulium is used in euro banknotes for its blue fluorescence under UV light to defeat counterfeiters.