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The biological half-life of strontium in humans has variously been reported as from 14 to 600 days, [86] [87] 1,000 days, [88] 18 years, [89] 30 years [90] and, at an upper limit, 49 years. [91] The wide-ranging published biological half-life figures are explained by strontium's complex metabolism within the body.
In December 1901 and January 1902, at the direction of archaeologist Jacques de Morgan, Father Jean-Vincent Scheil, OP found a 2.25 meter (or 88.5 inch) tall basalt or diorite stele in three pieces inscribed with 4,130 lines of cuneiform law dictated by Hammurabi (c. 1792–1750 BC) of the First Babylonian Empire in the city of Shush, Iran.
The longest-lived of these isotopes, and the most relevantly studied, are 90 Sr with a half-life of 28.9 years, 85 Sr with a half-life of 64.853 days, and 89 Sr (89 Sr) with a half-life of 50.57 days. All other strontium isotopes have half-lives shorter than 50 days, most under 100 minutes.
Some authors credit Cruickshank with first suspecting an unknown substance in a Scottish mineral, strontianite, found near Strontian, in Argyleshire.Other authors name Adair Crawford for the discovery of this new earth, due to the mineral's property of imparting a redding color to a flame. [10]
Life insurance (or life assurance, especially in the Commonwealth of Nations) is a contract between an insurance policy holder and an insurer or assurer, where the insurer promises to pay a designated beneficiary a sum of money upon the death of an insured person.
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.
The element was eventually isolated by Sir Humphry Davy in 1808 by the electrolysis of a mixture containing strontium chloride and mercuric oxide, and announced by him in a lecture to the Royal Society on 30 June 1808. [8] In keeping with the naming of the other alkaline earths, he changed the name to strontium.
A scenario is a set of related concepts pertinent to the origin of life (abiogenesis), such as the iron-sulfur world. Many alternative abiogenesis scenarios have been proposed by scientists in a variety of fields from the 1950s onwards in an attempt to explain how the complex mechanisms of life could have come into existence. These include ...