## Thulium |

Symbol | Tm |
---|---|

Latin name | Thulium |

Atomic number | 69 |

Period | 6 |

Element category | Inner transition elements |

Relative atomic mass | 168.93421 |

Group | III.B |

Electronegativity | 1.2 |

Oxidation numbers | 2, 3 |

Electron configuration | 1s ^{2} 2s^{2} 2p^{6} 3s^{2} 3p^{6} 3d^{10} 4s^{2} 4p^{6} 4d^{10} 5s^{2} 5p^{6} 4f^{13} 5d^{0} 6s^{2} |

Density [g/cm^{3}] | 9.318 |

State | Solid |

Melting point [°C] | 1545 |

Boiling point [°C] | 1947 |

Atomic radius [pm] | 222 |

Thermal conductivity [W m^{-1}K^{-1}] | 16.8 |

Heat capacity [J K^{-1}g^{-1}] | 0.16 |

Discovery | 1879 |

Vickers hardness [MPa] | 520 |

Brinell hardness [MPa] | 471 |

Young's modulus [GPa] | 74 |

Electrical conductivity [S m^{-1}] | 1.4 · 10 ^{6} |

Shear modulus [GPa] | 31 |

1.st ionization energy [eV] | 6.1843 |

2.nd ionization energy [eV] | 12.054 |

3.rd ionization energy [eV] | 26.367 |

Stable isotopes | 1 |

Unstable isotopes | 17 |