Carbon DatingYou are currentlybrowsing as guest. Click here to log in 

Carbon dating is a technique for discovering the age of ancient onceliving objects, such as bone, charcoal or a piece of wood, by measuring the amount of the radioactive isotope Carbon14 ( $^{14}C$ ) that it contains.
Whilst plants and animals are alive their Carbon14 remains constant, but when they die it decreases due to radioactive decay.
The amount, A, of Carbon14 in an object t thousand years after it dies is given by the formula:
$A=15.3\times\(0.886)^t$
(The quantity A measures the rate of Carbon14 atom disintegration and this is measured in “counts per minute per gram of carbon” cpm/g)
(a) Using a calculator, draw a table of values to show how the amount of Carbon14 in an object varies with time. (Correct to 2 decimal places).
(b) Draw a graph of this data.
(c) Imagine that you have a fresh sample of tree wood. What is the rate of Carbon14 atom disintegration?
(d) Imagine you have a sample of charcoal from Stonehenge and it is 4000 years old. What is the rate of Carbon14 atom disintegration?
(e) Charcoal from the famous Lascaux caves in France gave a count of 2.34 cpm/g. Estimate the date of formation of the charcoal.
(f) Investigate "halflife" of a radioactive isotope.
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