How to find abundance of 206, 207 and 208 Pb

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In summary: Also, since 206Pb = x, then 207Pb = 0.2515x and 208Pb = 0.0581x. Plugging these values into the equation, we get x + 0.2515x + 0.0581x = 1. Solving for x, we get x = 0.7984. So, the abundance of 206Pb is 0.7984 or 79.84%, the abundance of 207Pb is 0.2015 or 20.15%, and the abundance of 208Pb is 0.0461 or 4.61%. In summary, to find
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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?
 
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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.
 
  • #4
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.

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?
 
  • #5
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?

I would use the definition... 206Pb + 207Pb + 208Pb = 1
 

1. How can I find abundance of 206, 207 and 208 Pb in a sample?

To determine the abundance of these isotopes, you can use mass spectrometry techniques. This involves separating the different isotopes based on their mass-to-charge ratio and then measuring the relative abundance of each isotope. Another method is through radioactive decay analysis, where the decay rate of each isotope is measured and used to calculate their abundance.

2. What factors influence the abundance of 206, 207 and 208 Pb?

The abundance of these isotopes can be affected by several factors, including the geological age of the sample, the type of rock or mineral it is found in, and the presence of other elements that may interfere with the measurement. Additionally, the isotopic composition of the Earth's crust and the decay of other radioactive elements can also impact the abundance of these isotopes.

3. Can the abundance of 206, 207 and 208 Pb be used to determine the age of a sample?

Yes, the relative abundance of these isotopes can be used in radiometric dating to determine the age of a sample. This is based on the fact that certain isotopes, such as 238U, decay at a constant rate and can be used as a "clock" to measure the age of a material.

4. Are there any natural sources that can alter the abundance of 206, 207 and 208 Pb?

Yes, natural processes such as volcanic activity, weathering, and erosion can cause changes in the abundance of these isotopes. Additionally, human activities such as mining and burning of fossil fuels can also impact the isotopic composition of lead in the environment.

5. How is the abundance of 206, 207 and 208 Pb measured in the environment?

The abundance of these isotopes can be measured in various environmental samples, such as rocks, sediments, and water, using specialized instruments such as mass spectrometers. These instruments can detect and measure the different isotopes present in a sample and calculate their relative abundances.

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