A radiation detector in a labaratory records a reading of 10 counts / min. There are no radioactive samples in the laboratory. Carbon has a half life of 5700 years. There are atoms of carbon-14 in all living organisms. An archaeologist digs up some ancient wood gives a reading of 20 counts / min. Sn equivalent sample of living wood gives a rreading of 80 counts / min. Do a calculation to check whether this suggestion is correct.
Question
A radiation detector in a labaratory records a reading of 10 counts / min. There are no radioactive samples in the laboratory. Carbon has a half life of 5700 years. There are atoms of carbon-14 in all living organisms. An archaeologist digs up some ancient wood gives a reading of 20 counts / min. Sn equivalent sample of living wood gives a rreading of 80 counts / min. Do a calculation to check whether this suggestion is correct.
Solution
The question seems to be asking whether the age of the ancient wood can be determined based on the given radioactive decay rates. To answer this, we can use the concept of half-life, which is the time it takes for half of the radioactive atoms in a sample to decay.
Here are the steps to solve this problem:
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First, we need to correct the readings for background radiation. The background radiation is 10 counts/min, so we subtract this from the readings. The corrected reading for the ancient wood is 20 - 10 = 10 counts/min, and for the living wood is 80 - 10 = 70 counts/min.
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Next, we calculate the ratio of the corrected readings of the ancient wood to the living wood. This gives us 10 / 70 = 0.143.
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The half-life of carbon-14 is 5700 years. This means that after 5700 years, half of the carbon-14 in a sample will have decayed.
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We can use the formula for radioactive decay, which is N = N0 * (1/2)^(t/T), where N is the final quantity, N0 is the initial quantity, t is the time, and T is the half-life.
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In this case, we know that N/N0 = 0.143, and we're trying to find t. We can rearrange the formula to solve for t: t = T * log2(N0/N).
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Substituting the given values into the formula gives us t = 5700 * log2(70/10) = 5700 * log2(7) = 5700 * 2.807 = 16,000 years.
So, the calculation suggests that the ancient wood is approximately 16,000 years old. This is a rough estimate, as the actual age could be slightly different due to factors such as variations in the carbon-14 concentration in the atmosphere over time.
Similar Questions
The half-life for radioactive decay of 14C is 5730 years. An archaeological artifact containing wood had only 80% of the 14C found in a living tree. Estimate the age of the sample.
Carbon-14 is a radioactive nucleus with a half-life of 5760 years. In livingmatter the amount of carbon-14 decays at a rate of 15.3 decay events perminute per gram of carbon. A fossil is analysed and found to have a carbon-14 decay rate of 7.70 decay events per minute per gram of carbon. How oldis the fossil?
Select the statement that is falseGroup of answer choicesActivity is proportional to the number of nuclei in the sampleThe rate of decay depends on the number of nuclei presentC-14 dating is appropriate for objects up to one million years oldA high activity corresponds to a short half-life
Select the statement that is falseGroup of answer choicesC-14 dating is only appropriate for objects less than 60000 years oldA high activity corresponds to a large decay constantThe half-lives of radioactive nuclides are very similar in magnitudeThe decay constant (k) does not depend on the amount of sample
If a fossil was found that had 50% radioactive carbon-14 and 50% decayed element, approximately how old is the fossil?
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