What is Strontium?
[[File:Sr,38.jpg|thumb|[[Granule]]s of strontium in a glass tube]] [[File:Stronzianite 01.png|thumb|A piece of [[strontianite]]]] '''Strontium''' is a [[chemical element]]. It has the chemical symbol '''Sr'''. It has the [[atomic number]] 38. It is a [[metal]]. The color of the metal is silver-white or yellow-silver. The metal is [[wikt:soft|soft]], and highly [[reactivity (chemistry)|reactive]] chemically. In chemistry it is placed in a group of metal elements named the [[alkaline earth metal]]s. Strontium has a high [[chemical reactivity]]. The metal turns yellow when exposed to air. Strontium has properties similar to those of its two vertical neighbors in the [[periodic table]], [[calcium]] and [[barium]]. It is found naturally in the [[mineral]]s [[celestite]] and [[strontianite]]. The <sup>90</sup>Sr [[isotope]] is present in [[radioactive]] [[nuclear fallout|fallout]] and has a [[Half-life (element)|half-life]] of 28.9 years. Strontium forms salts which make a red flame when they burn. They are used in flares for signalling the position of survivors or shipwrecks and to make the red color in fireworks. It is named after the village of Strontian, Scotland. {{-}} {{Commons}} {{wiktionary}} {{Periodic Table}} {{chem-stub}} {{authority control}} [[Category:Alkaline earth metals]]