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Strontium is a chemical element; it has symbol Sr and atomic number 38. 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.
The rubidium–strontium dating method (Rb–Sr) is a radiometric dating technique, used by scientists to determine the age of rocks and minerals from their content of specific isotopes of rubidium (87 Rb) and strontium (87 Sr, 86 Sr). One of the two naturally occurring isotopes of rubidium, 87 Rb, decays to 87 Sr with a half-life of 49.23 ...
Celestine (the IMA-accepted name) [6] or celestite [1] [7] [a] is a mineral consisting of strontium sulfate (Sr S O 4). The mineral is named for its occasional delicate blue color. Celestine and the carbonate mineral strontianite are the principal sources of the element strontium, commonly used in fireworks and in various metal alloys.
The ratio 87 Sr/ 86 Sr is the parameter typically reported in geologic investigations; [4] ratios in minerals and rocks have values ranging from about 0.7 to greater than 4.0 (see rubidium–strontium dating). Because strontium has an electron configuration similar to that of calcium, it readily substitutes for calcium in minerals.
Strontium and barium have fewer applications than the lighter alkaline earth metals. Strontium carbonate is used in the manufacturing of red fireworks. [75] Pure strontium is used in the study of neurotransmitter release in neurons. [76] [77] Radioactive strontium-90 finds some use in RTGs, [78] [79] which utilize its decay heat.
Naturally occurring strontium is nonradioactive and nontoxic at levels normally found in the environment, but 90 Sr is a radiation hazard. [4] 90 Sr undergoes β − decay with a half-life of 28.79 years and a decay energy of 0.546 MeV distributed to an electron, an antineutrino, and the yttrium isotope 90 Y, which in turn undergoes β − decay with a half-life of 64 hours and a decay energy ...
Strontium: 1787 W. Cruikshank: 1808 H. Davy W. Cruikshank in 1787 and Adair Crawford in 1790 concluded that strontianite contained a new earth. It was eventually isolated electrochemically in 1808 by Davy. [89] 5 Boron: 1787 L. Guyton de Morveau, A. Lavoisier, C. L. Berthollet, and A. de Fourcroy: 1809 H. Davy: Borax was known from ancient times.
The rare-earth elements patterns observed in igneous rocks are primarily a function of the chemistry of the source where the rock came from, as well as the fractionation history the rock has undergone. [27] Fractionation is in turn a function of the partition coefficients of each element. Partition coefficients are responsible for the ...