Strontium (Sr) is chemical element 38, an alkaline earth metal in group 2, period 5 (PubChem).
- Atomic number: 38
- Symbol: Sr
- Group: 2
- Period: 5
- Atomic mass: 87.62 u
- Electron configuration: [Kr]5s2
- Electronegativity (Pauling scale): 0.95
- Atomic radius (van der Waals): 249 pm
- Ionization energy: 5.695 eV
- Oxidation states: +2
- Standard state: Solid
- Melting point: 1050 K
- Boiling point: 1655 K
- Density: 2.64 g/cm³
- Chemical group: Alkaline earth metal
- Year discovered: 1790