Strontium is a chemical element ; it has symbol Sr and atomic number An alkaline earth metal , strontium is a soft silver-white yellowish metallic element that is highly chemically reactive. The metal forms a dark oxide layer when it is exposed to air. Strontium has physical and chemical properties similar to those of its two vertical neighbors in the periodic table, calcium and barium. It occurs naturally mainly in the minerals celestine and strontianite , and is mostly mined from these.
Both strontium and strontianite are named after Strontian , a village in Scotland near which the mineral was discovered in by Adair Crawford and William Cruickshank ; it was identified as a new element the next year from its crimson-red flame test color. Strontium was first isolated as a metal in by Humphry Davy using the then newly discovered process of electrolysis. During the 19th century, strontium was mostly used in the production of sugar from sugar beets see strontian process.
While natural strontium which is mostly the isotope strontium is stable, the synthetic strontium is radioactive and is one of the most dangerous components of nuclear fallout , as strontium is absorbed by the body in a similar manner to calcium. Natural stable strontium, on the other hand, is not hazardous to health. Strontium is a divalent silvery metal with a pale yellow tint whose properties are mostly intermediate between and similar to those of its group neighbors calcium and barium.
The density of strontium 2. Due to the large size of the heavy s-block elements, including strontium, a vast range of coordination numbers is known, from 2, 3, or 4 all the way to 22 or 24 in SrCd 11 and SrZn Organostrontium compounds contain one or more strontium—carbon bonds. They have been reported as intermediates in Barbier-type reactions. Most of these compounds can only be prepared at low temperatures; bulky ligands tend to favor stability.
For example, strontium di cyclopentadienyl , Sr C 5 H 5 2 , must be made by directly reacting strontium metal with mercurocene or cyclopentadiene itself; replacing the C 5 H 5 ligand with the bulkier C 5 CH 3 5 ligand on the other hand increases the compound's solubility, volatility, and kinetic stability.
