# Rúbídíọ̀mù

Rubidium, 37Rb|  |
| Rubidium |
| Pípè |  /ruːˈbɪdiəm/ ​(*roo-BID-ee-əm*) |
| Ìhànsójú | grey white |
| Ìwúwo átọ̀mù *A*r, std(Rb) | 85.4678(3) |
| Rubidium ní orí tábìlì àyè |
|

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|  |  |  |
| --- | --- | --- |
| Hydrogen |  | Helium |
| Lithium | Beryllium |  | Boron | Carbon | Nitrogen | Oxygen | Fluorine | Neon |
| Sodium | Magnesium |  | Aluminium | Silicon | Phosphorus | Sulfur | Chlorine | Argon |
| Potassium | Calcium | Scandium |  | Titanium | Vanadium | Chromium | Manganese | Iron | Cobalt | Nickel | Copper | Zinc | Gallium | Germanium | Arsenic | Selenium | Bromine | Krypton |
| Rubidium | Strontium | Yttrium |  |  | Zirconium | Niobium | Molybdenum | Technetium | Ruthenium | Rhodium | Palladium | Silver | Cadmium | Indium | Tin | Antimony | Tellurium | Iodine | Xenon |
| Caesium | Barium | Lanthanum | Cerium | Praseodymium | Neodymium | Promethium | Samarium | Europium | Gadolinium | Terbium | Dysprosium | Holmium | Erbium | Thulium | Ytterbium | Lutetium | Hafnium | Tantalum | Tungsten | Rhenium | Osmium | Iridium | Platinum | Gold | Mercury (element) | Thallium | Lead | Bismuth | Polonium | Astatine | Radon |
| Francium | Radium | Actinium | Thorium | Protactinium | Uranium | Neptunium | Plutonium | Americium | Curium | Berkelium | Californium | Einsteinium | Fermium | Mendelevium | Nobelium | Lawrencium | Rutherfordium | Dubnium | Seaborgium | Bohrium | Hassium | Meitnerium | Darmstadtium | Roentgenium | Copernicium | Nihonium | Flerovium | Moscovium | Livermorium | Tennessine | Oganesson |

 | K ↑ **Rb** ↓ Cs |
| krypton ← **rubidium** → strontium |

 |

 |
| Nọ́mbà átọ̀mù (*Z*) | 37 |
| Ẹgbẹ́ | group 1: H and alkali metals |
| Àyè | àyè 5  |
| Àdìpọ̀ | Àdìpọ̀-s  |
| Ẹ̀ka ẹ́límẹ́ntì |   Alkali metal |
| Ìtò ẹ̀lẹ́ktrọ́nù | [Kr] 5s1 |
| Iye ẹ̀lẹ́ktrọ́nù lórí ìpele kọ̀ọ̀kan | 2, 8, 18, 8, 1 |
| Àwọn ohun ìní ara |
| Ìfarahàn at STP | solid |
| Ìgbà ìyọ́ | 312.46 K ​(39.31 °C, ​102.76 °F)  |
| Ígbà ìhó | 961 K ​(688 °C, ​1270 °F)  |
| Kíki (near r.t.) | 1.532 g/cm3 |
| when liquid (at m.p.) | 1.46 g/cm3  |
| Critical point | (extrapolated) 2093 K, 16 MPa  |
| Heat of fusion | 2.19 kJ/mol  |
| Heat of  | 75.77 kJ/mol  |
| Molar heat capacity | 31.060 J/(mol·K)  |
| **pressure**

| *P* (Pa) | 1 | 10 | 100 | 1 k | 10 k | 100 k |
| --- | --- | --- | --- | --- | --- | --- |
| at *T* (K) | 434 | 486 | 552 | 641 | 769 | 958 |

 |
| Atomic properties |
| Oxidation states | −1, **+1** Àdàkọ:Infobox element/symbol-to-oxidation-state/comment |
| Electronegativity | Pauling scale: 0.82  |
| Atomic radius | empirical: 248 pm  |
| Covalent radius | 220±9 pm  |
| Van der Waals radius | 303 pm  |
| Color lines in a spectral range**Spectral lines of rubidium** |
| Other properties |
| Natural occurrence | primordial |
| Crystal structure |  ​(bcc) |
| Speed of sound  thin rod | 1300 m/s (at 20 °C)  |
| Thermal conductivity | 58.2 W/(m·K)  |
| Electrical resistivity | 128 n Ω·m (at 20 °C)  |
| Magnetic ordering | paramagnetic  |
| Young's modulus | 2.4 GPa  |
| Bulk modulus | 2.5 GPa  |
| Mohs hardness | 0.3  |
| Brinell hardness | 0.216 MPa  |
| CAS Number | 7440-17-7  |
| Main isotopes of rubidium |
|

| Iso­tope | Abun­dance | Half-life (*t*1/2) | Decay mode | Pro­duct |
| --- | --- | --- | --- | --- |
| 83Rb | syn | 86.2 d | ε | - | 83Kr |
| γ | 0.52, 0.53, 0.55 | - |
| 84Rb | syn | 32.9 d | ε | - | 84Kr |
| β+ | 1.66, 0.78 | 84Kr |
| γ | 0.881 | - |
| β− | 0.892 | 84Sr |
| 85Rb | 72.168% | 85Rb is stable with 48 neutrons |
| 86Rb | syn | 18.65 d | β− | 1.775 | 86Sr |
| γ | 1.0767 | - |
| 87Rb | 27.835% | 4.88 × 1010 y | β− | 0.283 | 87Sr |

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## Itokasi