Strontium is a soft, silvery-white metal that belongs to the alkaline earth metals group in the periodic table. It is represented by the symbol Sr and has the atomic number 38. Strontium is commonly found in nature, primarily in minerals like celestine and strontianite. It is used in various applications, including fireworks, where it produces a bright red color, and in the production of certain types of glass. In addition to its industrial uses, strontium has important roles in biology. For example, strontium-90, a radioactive isotope, is a byproduct of nuclear reactions and can be harmful to health. However, non-radioactive strontium is sometimes used in dental products to help reduce sensitivity and strengthen teeth.