SCIENCE
EARTH SCIENCE
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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5, 700 years
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11, 400 years
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17, 100 years
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22, 800 years
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Detailed explanation-1: -Notice that we did not need to know how much 14C was contained in our original sample. We only needed to know that a certain percentage of it remained. Our answer makes sense since 50% would remain after 5700 years, 25% would remain after 11, 400 years, and 12.5% would remain after 17, 100 years.
Detailed explanation-2: -Therefore, the estimated age of this sample is 17, 151 years old.
Detailed explanation-3: -If an archaeologist found a fossil sample that contained 25% carbon-14 in comparison to a living sample, the time of the fossil sample’s death could be determined by rearranging equation 1, since Nt, N0, and t1/2 are known. This means that the fossil is 11, 460 years old.
Detailed explanation-4: -A rock contains 12.5% of its original K40 (half life= 704 million years). How old is the rock? A radioactive isotope of element X (which is the parent isotope) is discovered in different amounts in four rocks.