subopolois
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how would i find the abundance of Pb 206, 207 and 208 if I am given the isotopic data of 207Pb/206Pb and 208Pb/206Pb?
The discussion focuses on calculating the molar fractions of lead isotopes 206Pb, 207Pb, and 208Pb using given isotopic ratios. Participants confirm that the molar fractions must sum to 1 and can be derived from the ratios 207Pb/206Pb and 208Pb/206Pb. The example provided includes a lead content of 468 ppm, with specific ratios of 0.2515 for 207Pb/206Pb and 0.0581 for 208Pb/206Pb. The solution involves setting up simultaneous equations to solve for the individual molar fractions.
PREREQUISITESChemists, geologists, and students studying isotopic analysis or radiometric dating techniques will benefit from this discussion.
chemisttree said:OK... Assume that the expression 206Pb means the molar fraction of lead-206. The same is true for 207Pb and 208Pb. You know that the molar fractions sum to 1 as well as the molar ratios of 207Pb/206Pb and 208Pb/206Pb. You can also calculate 207Pb/208Pb. From here it is merely solving for the simultaneous equations.
subopolois said:ok, i think i get it. here's my scenerio,
the Pb content is 468ppm
207Pb/206Pb= 0.2515
208Pb/206Pb= 0.0581
i could just use abgebra to find each right?
206=x
207=0.2515x
208=0.0581x
i just solve for x and put it back into the previous equation?