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A wooden article and a freshly cut tree ...

A wooden article and a freshly cut tree show activity 7.6 counts `"min"^(-1) g^(-1)` and 15.2 counts `"min"^(-1) g^(-1)` of carbon (`t_(1//2) = 5760` years) respectively . The age of the article is :

A

5760 years

B

`5760 xx (15.2)/(6)` years

C

`5760 xx (7.6)/(15.2)` years

D

`5760 xx (15.2 - 7.6)` year

Text Solution

AI Generated Solution

The correct Answer is:
To determine the age of the wooden article, we can use the concept of radioactive decay, specifically the decay of carbon-14. The activity of a sample is directly proportional to the amount of carbon-14 present, and we can use the following formula to find the age: \[ t = \frac{t_{1/2}}{0.693} \cdot \log\left(\frac{A_0}{A}\right) \] Where: - \( t \) = age of the sample - \( t_{1/2} \) = half-life of carbon-14 (5760 years) - \( A_0 \) = activity of the fresh cut tree (15.2 counts min\(^{-1}\) g\(^{-1}\)) - \( A \) = activity of the wooden article (7.6 counts min\(^{-1}\) g\(^{-1}\)) ### Step-by-Step Solution: 1. **Identify the given values:** - \( A_0 = 15.2 \) counts min\(^{-1}\) g\(^{-1}\) - \( A = 7.6 \) counts min\(^{-1}\) g\(^{-1}\) - \( t_{1/2} = 5760 \) years 2. **Calculate the ratio of activities:** \[ \frac{A_0}{A} = \frac{15.2}{7.6} = 2 \] 3. **Use the logarithm in the formula:** \[ \log\left(\frac{A_0}{A}\right) = \log(2) \] 4. **Calculate \( \log(2) \):** \[ \log(2) \approx 0.301 \] 5. **Substitute the values into the age formula:** \[ t = \frac{5760}{0.693} \cdot 0.301 \] 6. **Calculate \( \frac{5760}{0.693} \):** \[ \frac{5760}{0.693} \approx 8305.2 \] 7. **Now calculate the age \( t \):** \[ t \approx 8305.2 \cdot 0.301 \approx 2500.0 \text{ years} \] 8. **Final result:** The age of the wooden article is approximately **2500 years**.

To determine the age of the wooden article, we can use the concept of radioactive decay, specifically the decay of carbon-14. The activity of a sample is directly proportional to the amount of carbon-14 present, and we can use the following formula to find the age: \[ t = \frac{t_{1/2}}{0.693} \cdot \log\left(\frac{A_0}{A}\right) \] Where: - \( t \) = age of the sample ...
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