## Hafnium |

Symbol | Hf |
---|---|

Latin name | Hafnium |

Atomic number | 72 |

Period | 6 |

Element category | Transition elements |

Relative atomic mass | 178.49 |

Group | IV.B |

Electronegativity | 1.3 |

Oxidation numbers | 4 |

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^{14} 5d^{2} 6s^{2} |

Density [g/cm^{3}] | 13.3 |

State | Solid |

Melting point [°C] | 2227 |

Boiling point [°C] | 4600 |

Atomic radius [pm] | 208 |

Covalent radius [pm] | 150 |

Thermal conductivity [W m^{-1}K^{-1}] | 23 |

Heat capacity [J K^{-1}g^{-1}] | 0.14 |

Discovery | 1864 |

Hardness [Mohs scale] | 5.5 |

Vickers hardness [MPa] | 1760 |

Brinell hardness [MPa] | 1700 |

Young's modulus [GPa] | 78 |

Electrical conductivity [S m^{-1}] | 3.3 · 10 ^{6} |

Shear modulus [GPa] | 30 |

1.st ionization energy [eV] | 6.8251 |

2.nd ionization energy [eV] | 14.925 |

3.rd ionization energy [eV] | 23.32 |

Stable isotopes | 6 |

Unstable isotopes | 15 |