Thulium (Tm)
Thulium
Thulium (Tm) is a lanthanide in period 6. Its relative atomic mass is 168.93 and the molar mass of the atom is 168.93 g/mol.
Atomic number 69
Atomic mass 168.93
Molar mass 168.93 g/mol
Category Lanthanide Solid
Properties of thulium
| Atomic number | 69 |
|---|---|
| Symbol | Tm |
| Latin name | Thulium |
| Relative atomic mass | 168.93 |
| Molar mass | 168.93 g/mol |
| Group, period, block | —, 6, f |
| Category | Lanthanide |
| State at 20 °C | Solid |
| Electron configuration | [Xe] 4f¹³ 6s² |
| Electronegativity (Pauling) | 1.25 |
| Atomic radius | 175 pm |
Electron configuration of thulium
Electrons per shell
K2L8M18N31O8P2
Full notation
1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 4f¹³ 5s² 5p⁶ 6s²
Noble-gas notation
69 protons · 69 electrons[Xe] 4f¹³ 6s²
Formula and compounds of thulium
Simple substanceTmthuliumMolar mass of Tm: 168.93 g/mol
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Frequently asked questions
The relative atomic mass of thulium is 168.93, so the molar mass of the atom is 168.93 g/mol.
Full: 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 4f¹³ 5s² 5p⁶ 6s². Noble-gas notation: [Xe] 4f¹³ 6s².