## Promethium |

Symbol | Pm |
---|---|

Latin name | Promethium |

Atomic number | 61 |

Period | 6 |

Element category | Inner transition elements |

Relative atomic mass | 146.9151 |

Group | III.B |

Electronegativity | 1.2 |

Oxidation numbers | 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^{5} 5d^{0} 6s^{2} |

Density [g/cm^{3}] | 7.23 |

State | Solid |

Melting point [°C] | 1168 |

Boiling point [°C] | 2460 |

Atomic radius [pm] | 205 |

Thermal conductivity [W m^{-1}K^{-1}] | 17.9 |

Discovery | 1945 |

Young's modulus [GPa] | 46 |

Electrical conductivity [S m^{-1}] | 1.3 · 10 ^{6} |

Shear modulus [GPa] | 18 |

1.st ionization energy [eV] | 5.55 |

2.nd ionization energy [eV] | 10.903 |

3.rd ionization energy [eV] | 22.283 |

Stable isotopes | 0 |

Unstable isotopes | 14 |