Question

Radiometric dating uses the rate of decay of certain radioactive isotopes, such as carbon-14 to date relics of past life. The Scientific Skills Exercise on p. 33 explains this process. The half-life of carbon 14 is 5730 years. How old would a piece of ancient wood be if only 4 of this isotope remains?

Answer 1

To determine the age of the ancient wood, we can use the concept of half-life. Since the half-life of carbon-14 is 5730 years, we know that after each half-life, the amount of carbon-14 remaining is halved.

If only 4 carbon-14 isotopes remain, it means that half of the original amount has decayed. Therefore, we can calculate the number of half-lives that have occurred.

4 isotopes remaining is half of the original amount, so there has been 1 half-life.

Since each half-life is 5730 years, we can multiply the number of half-lives by the length of one half-life to find the age of the ancient wood.

1 half-life * 5730 years = 5730 years

Therefore, the piece of ancient wood would be approximately 5730 years old ! :)