Question

The half life of carbon 14 is 5730 years what fraction of the original c14 would you expect to be present in a fossil that is 28,650 years old

Answer 1

After 28,650 years, which equates to five half-lives of carbon-14, one would expect 1/32 or approximately 3.125% of the original carbon-14 to remain in the fossil.

Step-by-step explanation:

The question asks about the fraction of carbon-14 (14C) that would be present in a fossil that is 28,650 years old. Knowing that the half-life of 14C is 5,730 years, we can determine this fraction by considering the number of half-lives that have passed.

Since 28,650 years is 5 times the half-life of 14C, we would expect 1/25 (or 1/32) of the original 14C to remain in the fossil. Therefore, the fraction of the original 14C that we would expect to be present in the fossil is 1/32 or approximately 3.125%.

Answer 2

The half-life of a radioisotope describes the amount of time required for one-half of the isotope to decay into a daughter atom. After one half-life, 50% remains; after two, 25%, and so on.

To find how many half-lives have passed in 28,650 years, we can divide it by the time it takes for one half-life to pass. This reveals that five half-lives have passed.

HL ———— 1 2 3 4 5
% remain - 50 25 12.5 6.25 3.125

After 28,650 years or 5 half-lives, 3.125% of the original radioisotope remains in the fossil.