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Lead (82 Pb) has four observationally stable isotopes: 204 Pb, 206 Pb, 207 Pb, 208 Pb. Lead-204 is entirely a primordial nuclide and is not a radiogenic nuclide.The three isotopes lead-206, lead-207, and lead-208 represent the ends of three decay chains: the uranium series (or radium series), the actinium series, and the thorium series, respectively; a fourth decay chain, the neptunium series ...
In this diagram the 204 Pb/ 206 Pb ratio (the reciprocal of the normal ratio) is plotted on the x-axis, so that a point on the y axis (zero 204 Pb/ 206 Pb) would have infinitely radiogenic Pb. The ratio plotted on this axis is the 207 Pb/ 206 Pb ratio, corresponding to the slope of a normal Pb/Pb isochron, which yields the age. The most ...
Since the exact rate at which uranium decays into lead is known, the current ratio of lead to uranium in a sample of the mineral can be used to reliably determine its age. The method relies on two separate decay chains , the uranium series from 238 U to 206 Pb, with a half-life of 4.47 billion years and the actinium series from 235 U to 207 Pb ...
Lead is perhaps the best example of a partly radiogenic substance, as all four of its stable isotopes (204 Pb, 206 Pb, 207 Pb, and 208 Pb) are present primordially, in known and fixed ratios. However, 204 Pb is only present primordially, while the other three isotopes may also occur as radiogenic decay products of uranium and thorium.
One of its great advantages is that any sample provides two clocks, one based on uranium-235's decay to lead-207 with a half-life of about 700 million years, and one based on uranium-238's decay to lead-206 with a half-life of about 4.5 billion years, providing a built-in crosscheck that allows accurate determination of the age of the sample ...
The NFL playoff picture got an shake-up in Week 14, as the Buccaneers overtook the Falcons for the NFC South lead and the Eagles secured a spot. NFL playoff picture, clinching scenarios: Chiefs ...
Isotope geochemistry is an aspect of geology based upon the study of natural variations in the relative abundances of isotopes of various elements.Variations in isotopic abundance are measured by isotope-ratio mass spectrometry, and can reveal information about the ages and origins of rock, air or water bodies, or processes of mixing between them.
An inflation report in the coming week will test the strength of the record-setting U.S. stocks rally and provide a crucial piece of data that could factor into the Federal Reserve's plans for ...