Sr

Strontium (symbol Sr, atomic number 38) is a soft, silvery-white alkaline earth metal. In air it quickly forms a protective oxide layer and is highly reactive with water, releasing hydrogen gas. In its compounds, strontium commonly exists in the +2 oxidation state.

Strontium occurs naturally in minerals such as celestite (SrSO4) and strontianite (SrCO3) and is present in small amounts in rocks and soils. It is one of the more abundant elements in the Earth's crust, though it is not concentrated in large ore deposits. The element was named after Strontian, a Scottish village where strontianite was first identified. It was isolated as a metal in 1808 by Humphry Davy through electrolysis of molten strontium salts.

Production and refining typically begin with mining celestite or strontianite. The ore is converted to a soluble form, such as SrCl2 or SrCO3, and then separated and purified to produce elemental strontium or commercially useful compounds. Modern production often involves electrolysis of molten strontium salts or reduction of strontium compounds to metal, depending on the desired product.

Applications of strontium include its use in pyrotechnics to produce a red flame, in ferrite magnets and certain glass and ceramic glazes, and in specialized medical and research contexts, particularly involving radioactive isotopes of strontium used in therapy and diagnostics. Its compounds also contribute to various industrial processes and materials.

Safety considerations include its reactivity with water and air, potential skin and respiratory irritation from dust, and the radiological hazards associated with radioactive isotopes. Proper handling and storage are essential to minimize hazards.