Radioactive isotopes can be used to find the age of rocks, fossils, or other artifacts. carbon-14 has a half-life of 5,730 years. suppose a sample of charcoal from a primitive fire pit contains one eighth of its original amount of carbon-14. how old is the sample?
a. 716 years
b. 17,190 years
c. 22,920 years
d. 45,840 years

B. 17,190 years

Explanation:

As we know that half life of Carbon-14 is 5730 years

Here half life is defined as the years after which the amount of carbon-14 will remain half of the initial amount.

Now we know that fire pit contains one eighth of the original amount

So here we can say that it took 3 times of half life as each half life will convert it into half of the initial amount.

So here we can say that after first half life the amount is given as

after second half life

after third half life

so total time in this given as