Strontium

Strontium

Symbol	Sr
Atomic Number	38
Atomic Mass	87.62 g.mol -1
Discovered by	Adair Crawford in 1790

What is Strontium?

• Strontium belongs to the group 2 elements of the periodic table, along with Be, Mg, Ca and Ba.

Table of Contents

• • • Chemical Properties of Strontium
    • Uses of Strontium
    • Properties of Strontium

Chemical Properties of Strontium

Uses of Strontium

• • • • Although strontium is not considered as an essential element and does not have any known biological role, it is present in all living organisms.
      • Strontium resembles the calcium element in its properties; like calcium, it is taken up and preferentially located in bones.
      • Here, strontium can have both beneficial and deleterious effects in humans depending on the amount taken up.
      • Strontium ranelate (C₁₂H₆N₂O₈SSr₂ ), a pharmacologic agent used to treat individuals with osteoporosis, is indicated to be used in Europe and Australia but not in Canada or in the United States. Similar efficiency in the delivery of strontium to bones of animals was found for strontium citrate.
      • Injectable acrylic bone cement is widely used in orthopaedic surgery to fix artificial prostheses. Conventional polymethylmethacrylate (PMMA) bone cement has been successfully used in arthroplasties of the hip, knee and other joints for the fixation of polymer or metallic prosthetic implants to living bone; however, it still has some potential problems and risks, such as poor adhesion of bone cement to the bone surface and high exothermic reaction during the polymerization

Properties of Strontium

• • • • It has an atomic number of 38, an atomic mass of 88, one oxidation state (+2) and four naturally occurring isotopes (⁸⁴Sr, ⁸⁶Sr, ⁸⁷Sr, ⁸⁸Sr), of which ⁸⁸Sr is the most abundant at 82.6% of the total mass.
      • Strontium is most similar chemically to the heavier alkali earth elements, Calcium, and Barium.
      • Strontium is a lithophile metallic element.
      • The size of the Sr²⁺ ion (118 pm) is intermediate between those of Ca²⁺ (100 pm) and K⁺ (138 pm), for which it may substitute in a variety of rock-forming minerals including K-feldspar, gypsum, plagioclase and, especially, calcite and dolomite, which are the main sources of Sr in stream water.
      • Some substitution for Ba also takes place in barite BaSO₄ and witherite BaCO₃.
      • Minerals of Sr are relatively rare but include strontianite SrCO₃ and celestite SrSO₄, which are mainly associated with hydrothermal deposits or pegmatites.
      • Strontium is strongly associated with calcium and is indicative of calcareous rocks, especially in association with Sr, Mg, and Ba. Where Ca and other elements indicate calcareous rocks and other elements (e.g., REEs) indicate felsic intrusives, bedrock geology may be favourable for skarn mineralization.