Strontium (Sr) is a chemical element in the alkaline earth metal group, which is a soft silver-white to yellowish metal in its pure form. It has chemical properties similar to calcium, magnesium, and barium.
The two major natural sources of strontium are the minerals celestine (, strontium sulfate) and strontianite (, strontium carbonate). Both the metal and strontianite are named for Strontian, a Scottish village near where it was first discovered in 1790 by Adair Crawford and William Cruickshank. The pure metal was first isolated by Humphry Davy in 1808 via electrolysis.
The most common use of strontium in recent years was in the production of cathode ray tubes used in television sets, which drastically declined after the advancement of flat screen technologies. Strontium salts are used for the manufacturing of fireworks and flares to produce a brilliant red color flame, and modern glow-in-the-dark paints contain strontium aluminate which absorbs light and slowly releases it. Strontium chloride hexahydrate is used in certain types of toothpaste for sensitive teeth.
Strontium is a mixture of four stable isotopes: , , , and , with the latter comprising 82.6% of all natural strontium. Unstable (radioactive) isotopes include and , both used in radiation therapy to treat bone cancer. Because of strontium's similar uptake in the body as calcium, higher doses of radioactive strontium (particularly as fallout from nuclear explosions) can cause bone cancer and leukemia.
- Royal Society of Chemistry. Periodic Table: Strontium. http://www.rsc.org/periodic-table/element/38/strontium (accessed 03/19/18).