# Stróńtíọ̀mù

Strontium, 38Sr|  |
| Strontium |
| Pípè |  /ˈstrɒnʃiəm,\_ʔtiəm/ ​(*STRON-shee-əm-,\_--tee-əm*) |
| Ìhànsójú | silvery white metallic |
| Ìwúwo átọ̀mù *A*r, std(Sr) | 87.62(1) |
| Strontium 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 |

 | Ca ↑ **Sr** ↓ Ba |
| rubidium ← **strontium** → yttrium |

 |

 |
| Nọ́mbà átọ̀mù (*Z*) | 38 |
| Ẹgbẹ́ | group 2 (alkaline earth metals) |
| Àyè | àyè 5  |
| Àdìpọ̀ | Àdìpọ̀-s  |
| Ẹ̀ka ẹ́límẹ́ntì |   Alkaline earth metal |
| Ìtò ẹ̀lẹ́ktrọ́nù | [Kr] 5s2 |
| Iye ẹ̀lẹ́ktrọ́nù lórí ìpele kọ̀ọ̀kan | 2, 8, 18, 8, 2 |
| Àwọn ohun ìní ara |
| Ìfarahàn at STP | solid |
| Ìgbà ìyọ́ | 1050 K ​(777 °C, ​1431 °F)  |
| Ígbà ìhó | 1655 K ​(1382 °C, ​2520 °F)  |
| Kíki (near r.t.) | 2.64 g/cm3 |
| when liquid (at m.p.) | 2.375 g/cm3  |
| Heat of fusion | 7.43 kJ/mol  |
| Heat of  | 136.9 kJ/mol  |
| Molar heat capacity | 26.4 J/(mol·K)  |
| **pressure**

| *P* (Pa) | 1 | 10 | 100 | 1 k | 10 k | 100 k |
| --- | --- | --- | --- | --- | --- | --- |
| at *T* (K) | 796 | 882 | 990 | 1139 | 1345 | 1646 |

 |
| Atomic properties |
| Oxidation states | +1, **+2** Àdàkọ:Infobox element/symbol-to-oxidation-state/comment |
| Electronegativity | Pauling scale: 0.95  |
| Atomic radius | empirical: 215 pm  |
| Covalent radius | 195±10 pm  |
| Van der Waals radius | 249 pm  |
| Color lines in a spectral range**Spectral lines of strontium** |
| Other properties |
| Natural occurrence | primordial |
| Crystal structure |  ​(fcc) |
| Thermal expansion | 22.5 µm/(m·K) (at 25 °C)  |
| Thermal conductivity | 35.4 W/(m·K)  |
| Electrical resistivity | 132 n Ω·m (at 20 °C)  |
| Magnetic ordering | paramagnetic  |
| Shear modulus | 6.1 GPa  |
| Poisson ratio | 0.28  |
| Mohs hardness | 1.5  |
| CAS Number | 7440-24-6  |
| Main isotopes of strontium |
|

| Iso­tope | Abun­dance | Half-life (*t*1/2) | Decay mode | Pro­duct |
| --- | --- | --- | --- | --- |
| 82Sr | syn | 25.36 d | ε | - | 82Rb |
| 83Sr | syn | 1.35 d | ε | - | 83Rb |
| β+ | 1.23 | 83Rb |
| γ | 0.76, 0.36 | - |
| 84Sr | 0.56% | 84Sr is stable with 46 neutrons |
| 85Sr | syn | 64.84 d | ε | - | 85Rb |
| γ | 0.514D | - |
| 86Sr | 9.86% | 86Sr is stable with 48 neutrons |
| 87Sr | 7.0% | 87Sr is stable with 49 neutrons |
| 88Sr | 82.58% | 88Sr is stable with 50 neutrons |
| 89Sr | syn | 50.52 d | ε | 1.49 | 89Rb |
| β− | 0.909D | 89Y |
| 90Sr | trace | 28.90 y | β− | 0.546 | 90Y |

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## Itokasi