discordance = (1-(206 Pb/ 238 U age / 207 Pb/ 206 Pb age)*100 - is that right? shouldn't it be 1/(1-( 206 Pb/ 238 U age / 207 Pb/ 235 U age)*100 which in my view better describes the "distance" to
[answer] This is easy - clearly all the Pb-206 is the radiogenic daughter product of U-238 in this rock. After one half-life, the 100 gm of U-238 would drop to 50 gm (and we would have 50 gm of Pb-206). After a second half-life, the 50 gm of U-238 would drop to 25 while the 50 gm of Pb-206 would increase to 75. Thus, two half lives.
The half-life decay for uranium to turn into lead is 4.5x 109 yr. How old is The method relies on two separate decay chains, the uranium series from 238U to 206Pb, with a half-life of 4.47 billion years and the actinium series from 235U 238 as the there is 137.88 times more U-238 than U-235. This means, the radiogenic Pb-. 206/Pb-207 ratio increases with time. The radiogenic Pb-208/ Pb207 coupled Pb‐U‐Th evolution diagram, which has an upper intersection on the concordia curve at the same time point as that determined by the Pb206/U238, Potassium, K-40, Ar-40 (Argon), 1.3 billion years. Uranium, U-238, Pb-206 (Lead) , 4.5 billion years. U-235, Pb-207 (Lead), 710 million years. U-234, Th-230 Uranium-238 (half-life = 4.5 109 years) disintegrates to stable lead-206 (92Pb 206) isotope.
How old is the rock? Uranium-238 undergoes a radioactive decay series consisting of 14 separate steps before producing stable lead-206. This series consists of eight α decays and Carbon-14, C14 Nitrogen-14, N14; Uranium-235, U235 Lead-207, Pb207; Potassium-40, K40 Argon-40, Ar40; Uranium-238, U238 Lead-206, Pb206 The two uranium-lead dates obtained from U-235 and U-238 have different The forming mineral will incorporate lead-204, lead-206 and lead-207 at the ratio When asteroids first coalesce they contain plenty of Uranium-238, but no Lead- 206. The only way to produce Lead-206 is as a radioactive decay daughter product 16 Apr 2021 The unstable Uranium-238 element.
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Carbon-14, C14 Nitrogen-14, N14; Uranium-235, U235 Lead-207, Pb207; Potassium-40, K40 Argon-40, Ar40; Uranium-238, U238 Lead-206, Pb206
U-238 is the parent, and Pb-206 is the daughter, and: A rock sample containing a relatively small amount Pb-206 is old. -are the true statements. Log in for more information. Added 7/30/2018 11:37:31 AM 238 U decays to 206 Pb with a half-life of 4.47 × 10 9 y.
discordance = (1-(206 Pb/ 238 U age / 207 Pb/ 206 Pb age)*100 - is that right? shouldn't it be 1/(1-( 206 Pb/ 238 U age / 207 Pb/ 235 U age)*100 which in my view better describes the "distance" to
A. What Is The Value Of The Rate Constant (k) For This Decay? B. Assuming That The Meteor Did Not Contain Any Pb-206 At The Time Of Its Formation, How Old Is This Meteor In Years? Because when one mole of U-238 decays, it produces one mole of Pb-206, the amount of U-238 that has undergone radioactive decay since the rock was formed is: 2.51 × 10 −5 g Pb × ( 1 mol Pb 206 g Pb ) × ( 1 mol U 1 mol Pb ) = 1.22 × 10 −7 mol U 2.51 × 10 −5 g Pb × ( 1 mol Pb 206 g Pb ) × ( 1 mol U 1 mol Pb ) = 1.22 × 10 −7 mol U The sample contains 40% U-238 and 60% Pb-206. The lead content came from decay of the uranium content.
of atoms of U 238 and Pb 206 means half of U has distintegrated. time taken = t 1/2.
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Also half. Figure 1.
As time passes, the ratio of Pb 206 to U 238 will increase and it is this which enables the age of the rock to be estimated. The half-life with which uranium 238 decays to form lead 206 is 4.46 billion years. After 4.5 billion years (the alleged age of the Earth), at least the same quantity of lead and uranium should therefore be present on the Earths surface.
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1/238 moles 238U and 0.376/206 moles of 206Pb: 238U: 0.004201681 moles. 206Pb: 0.001825243 moles. Divide one by the other gives you the atomic ratio 206Pb/238U = 0.434407767. Note the ratio goes up because 1 g of Pb contains more atoms than 1 g of U, because Pb is lighter than U. Next you need to work out the 238U decay constant from the halflife.
U & Pb). This built-in redundancy provides a powerful internal quality check which makes the method arguably the most robust and A mineral sample contains 43.20 mg of U-238 and 14.50 mg of Pb-206. What is the age of the mineral? Here is another set of numbers for this problem: 40.60 mg of U-238 and 12.80 mg of Pb-206. Use those numbers to do a parallel calculation as you study the following explanation. Exercise 2 Radiometric Ages 23 Lead-206/Uranium-238 0.12 0.08 0.04 - 0.
92 U 238 by successive radioactive decays changes to 82 Pb 206. A sample of uranium ore was analysed and found to contain 1.0 g U 238 and 0.1 g Pb 206. Assuming that Pb 206 has accumulated due to decay of uranium, find out the age of ore. t 1/2 for U 238 = 4.5 x 10 9 year.
By comparing the amount of U -238 to the amount of Pb -206 in a sample of uranium mineral, the age of the mineral can be estimated. The half-life with which uranium 238 decays to form lead 206 is 4.46 billion years. After 4.5 billion years (the alleged age of the Earth), at least the same quantity of lead and uranium should therefore be present on the Earths surface. However, in reality, there is more lead than uranium.
A. U-238 is the parent, and Pb-206 is the daughter. B. U-238 is the daughter, and Pb-206 is the parent. C. A rock sample containing a relatively small amount Pb-206 is old. D. A rock sample containing a relatively small amount of Pb-206 is young.