Question

The half-life of a radioactive isotope is the time it takes for a quantity of the isotope to be reduced to half its initial mass. Starting with 170 grams of a radioactive isotope, how much will be left after 4 half-lives? Use the calculator provided and round your answer to the nearest gram.

Answer 1

It will be left 11 grams of the radioactive isotope after four half-lives

Explanation:

Let's calculate the first four half-lives of the radioactive isotope, this way:

1. First half-life:

170 * 0.5 = 85 grams

2. Second half-life:

85 * 0.5 = 42.5 grams

3. Third half-life:

42.5 * 0.5 = 21.25 grams

4. Fourth half-life:

21.25 * 0.5 = 10.625 grams = 11 grams (Rounding to the nearest gram)