The graph you constructed so far applies to decay of any radioisotope. To calibrate it specifically to 14C, you need to calculate how many years must pass to reach the amount of remaining isotope for each point of the half-life curve.

Question

To calibrate the x-axis for 14C decay, you have to convert half-lives to number of years. Recall that 14C has a single half-life of 5,730 years. How many years make up 5 half-lives for 14C?

3.13 × 10–2 years
1,146 years
5,730 years
28,650 years

Answer 1

To calculate the number of years that make up 5 half-lives for carbon-14 (^14C), you multiply the length of one half-life by the number of half-lives:

1 half-life of ^14C = 5,730 years

So for 5 half-lives:

5 half-lives = 5 × 5,730 years = 28,650 years

Thus, the answer is:

28,650 years