Question 20 The half-life of the radioisotope strontium -90 is 29 years. How much of a 10 .0 g sample will remain after 87 years? 1.54g 1.23g 1.25g 2.03g Points 3

## Step 1: Determine the number of half-lives### We need to find out how many half-lives have passed in 87 years. We do this by dividing the total time elapsed (87 years) by the length of each half-life (29 years). ## Step 2: Calculate the remaining amount after the given half-lives### After 3 half-lives, the remaining amount of the sample can be calculated by halving the initial amount 3 times. #