Strontium

Strontium is a chemical element with symbol Sr and atomic number 38. An alkaline earth metal, strontium is a soft silver-white or yellowish metallic element that is highly reactive chemically. The metal turns yellow when it is exposed to air. Strontium has physical and chemical properties similar to those of its two vertical neighbors calcium and barium. It occurs naturally in the minerals celestine, putnisite and strontianite. While natural strontium is stable, the synthetic ⁹⁰Sr isotope is present in radioactive fallout and has a half-life of 28.90 years.

Both strontium and strontianite are named after Strontian, a village in Scotland near which the mineral was discovered in 1790 by Adair Crawford and William Cruickshank. The production of sugar from sugar beet was in the 19th century its largest application (see strontian process). At the peak of production of television cathode ray tubes, up to 75 percent of U.S. strontium consumption was used to make the faceplate glass. With the displacement of cathode ray tubes by other display methods in television sets, consumption of strontium has dramatically declined.

Strontium (disambiguation)

Strontium is a chemical element.

Strontium may also refer to:

See also

Strontium-90

Strontium-90 (90Sr) is a radioactive isotope of strontium produced by nuclear fission, with a half-life of 28.8 years. It undergoes β⁻ decay into yttrium-90, with a decay energy of 0.546 MeV. Strontium-90 has applications in medicine and industry and is an isotope of concern in fallout from nuclear weapons and nuclear accidents.

Radioactivity

Naturally occurring strontium is nonradioactive and nontoxic at levels normally found in the environment, but ⁹⁰Sr is a radiation hazard.⁹⁰Sr undergoes β⁻ decay with a half-life of 28.79 years and a decay energy of 0.546 MeV distributed to an electron, an anti-neutrino, and the yttrium isotope ⁹⁰Y, which in turn undergoes β⁻ decay with half-life of 64 hours and decay energy 2.28 MeV distributed to an electron, an anti-neutrino, and ⁹⁰Zr (zirconium), which is stable. Note that ⁹⁰Sr/Y is almost a pure beta particle source; the gamma photon emission from the decay of ⁹⁰Y is so infrequent that it can normally be ignored.

⁹⁰Sr has a specific activity of 5.21 TBq/g.