← Back to periodic table
Thulium (Tm)
Atomic number: 69 · Category: lanthanide · Group 3 · Period 6 · Phase: Solid
Thulium is a chemical element with symbol Tm and atomic number 69. It is the thirteenth and antepenultimate (third-last) element in the lanthanide series. Like the other lanthanides, the most common oxidation state is +3, seen in its oxide, halides and other compounds.
Atomic mass: 168.934222
Density: 9.32
Melting point: 1818 K
Boiling point: 2223 K
Appearance: silvery gray
Source: Wikipedia
Block: f
Molar heat: 27.03
CPK color:#00d452
Electronic structure
Electron configuration: 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f13
Configuration (semantic): [Xe] 4f13 6s2
Shells: 2, 8, 18, 31, 8, 2
Electronegativity (Pauling): 1.25
Electron affinity: 99
Ionization energies: 596.7, 1160, 2285, 4120
Periodic position
Group: 3
Period: 6
xpos: 15
ypos: 9
Spectral/Bohr images
Image
3D Model