Question

Now, lets make the skittles represent actual radioactive atoms. Let's make the parent skittles Carbon-14 and the daughter skittles Nitrogen-14 in our fossil. Carbon-14 is used to date most fossils found today.

The half life time of Carbon-14 takes 50,000 years for 1 half life. So if only 1 half life has passed we know that the fossil is approxmatley 50,000 years.

Using the information you just read, answer this Question:

How old is our Fossil after 2 half-lives have passed?

Answer 1

After 2 half-lives the fossil is about 2 × 50,000 = 100,000 years old.

(At that point only 1/4 of the original Carbon-14 remains.)