## Rubidium |

Symbol | Rb |
---|---|

Latin name | Rubidium |

Atomic number | 37 |

Period | 5 |

Element category | Alkali metals |

Relative atomic mass | 85.4678 |

Group | I.A |

Electronegativity | 0.8 |

Oxidation numbers | 1 |

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

Density [g/cm^{3}] | 1.532 |

State | Solid |

Melting point [°C] | 38.89 |

Boiling point [°C] | 688 |

Critical point [°C] | 1820 |

Critical pressure [MPa] | 16 |

Atomic radius [pm] | 265 |

Covalent radius [pm] | 211 |

Thermal conductivity [W m^{-1}K^{-1}] | 58.2 |

Heat capacity [J K^{-1}g^{-1}] | 0.363 |

Discovery | 1861 |

Hardness [Mohs scale] | 0.3 |

Brinell hardness [MPa] | 0.216 |

Young's modulus [GPa] | 2.4 |

Electrical conductivity [S m^{-1}] | 4.78 · 10 ^{7} |

1.st ionization energy [eV] | 4.1771 |

2.nd ionization energy [eV] | 27.28 |

3.rd ionization energy [eV] | 40.0 |

Stable isotopes | 2 |

Unstable isotopes | 19 |