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The half life for radioactive decay of ....

The half life for radioactive decay of `.^(14)C` is 5730 years. An archaeological artifact containing wood had only `80%` of the `.^(14)C` found in a living tree. Estimat the age of the sample.

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To estimate the age of the archaeological artifact containing wood, we can follow these steps: ### Step 1: Understand the given data - The half-life of Carbon-14 (\(^{14}C\)) is \(5730\) years. - The artifact contains \(80\%\) of the \(^{14}C\) found in a living tree. ### Step 2: Set up the ratio of remaining \(^{14}C\) Since the artifact has \(80\%\) of the original \(^{14}C\), we can express this as: \[ \frac{N}{N_0} = 0.8 \] where \(N\) is the amount of \(^{14}C\) in the artifact and \(N_0\) is the amount in a living tree. ### Step 3: Calculate the decay constant \(K\) The decay constant \(K\) can be calculated using the half-life formula: \[ K = \frac{0.693}{T_{1/2}} \] Substituting the half-life: \[ K = \frac{0.693}{5730} \approx 1.21 \times 10^{-4} \text{ year}^{-1} \] ### Step 4: Use the logarithmic decay formula We can use the formula relating \(K\), \(T\), and the ratio of \(N_0\) to \(N\): \[ K = \frac{2.303}{T} \log\left(\frac{N_0}{N}\right) \] Since \(\frac{N}{N_0} = 0.8\), we have: \[ \frac{N_0}{N} = \frac{1}{0.8} = 1.25 \] ### Step 5: Substitute values into the equation Now substituting \(K\) and \(\frac{N_0}{N}\) into the equation: \[ 1.21 \times 10^{-4} = \frac{2.303}{T} \log(1.25) \] ### Step 6: Calculate \(\log(1.25)\) Using a calculator: \[ \log(1.25) \approx 0.0969 \] ### Step 7: Rearranging to find \(T\) Now we can rearrange the equation to solve for \(T\): \[ T = \frac{2.303 \times 0.0969}{1.21 \times 10^{-4}} \] ### Step 8: Calculate \(T\) Calculating the above expression: \[ T \approx \frac{0.2231}{1.21 \times 10^{-4}} \approx 1845 \text{ years} \] ### Conclusion The estimated age of the archaeological artifact is approximately \(1845\) years. ---

To estimate the age of the archaeological artifact containing wood, we can follow these steps: ### Step 1: Understand the given data - The half-life of Carbon-14 (\(^{14}C\)) is \(5730\) years. - The artifact contains \(80\%\) of the \(^{14}C\) found in a living tree. ### Step 2: Set up the ratio of remaining \(^{14}C\) Since the artifact has \(80\%\) of the original \(^{14}C\), we can express this as: ...
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Half - life for radioactive .^(14)C is 5760 years. In how many years 200 mg of .^(14)C will be reduced to 25 mg ?

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