If you know how much radioactive material the organism had to begin with, explain how you could use half-life to determine its age now.

We can calculate it with the radioactive half life equation

Explanation:

If we already know the initial amount of radioactive material and its half life, we can leave that material for a specific known time and then measure how much of the material is left (since it follows the radioactive deacay) and use the results in the following formula:

Where:

is the final amount of the material

is the initial amount of the material

is the time elapsed

is the half life of the radioactive compound

more than, less

less than, more