69 Tm 168.934
Thulium
lanthanide
Properties
- Atomic number
- 69
- Atomic mass
- 168.934 u
- Category
- lanthanide
- Group
- f-block
- Period
- 6
- Block
- f-block
- State (room temp)
- Solid
- Outer-shell electrons
- 2
- Electronegativity
- 1.25 (Pauling)
- Density
- 9.32 g/cm³
- Melting point
- 1544.85 °C
- Boiling point
- 1949.85 °C
Electron configuration
1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f¹³
Noble-gas shorthand: [Xe] 4f¹³ 6s²
Electrons per shell: 2, 8, 18, 31, 8, 2 — that's 2 in the outermost shell.
About Thulium
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.
- Discovered by Per Teodor Cleve
- Appearance: silvery gray
Position in the periodic table
Data compiled from Wikipedia, PubChem, and IUPAC. Source.