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 130 grams of a radioactive isotope, how much will be left after 5 half-lives?

Use the calculator provided and round your answer to the nearest gram.

Answer 1

= 4 grams

Explanation:

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.

Therefore, using the formula;

N = O × (1/2)^n ; where N is the new mass, O is the original mass, and n is the number of half lives.

In this case;

N = 130 × (1/2)^5

= 130 × 1/32

= 4.0625

≈ 4 g