Question

An isotope of Technetium has a half-life of 6 hours. If it is given to a patient as part of a medical procedure,

what fraction of the radioisotope remains in the body after one day?

Answer 1

I think it’s 1/16.
Half-life is the time it takes to reduce a substance to half its amount. So after the first 6 hours, the body has half the amount. Then after another 6 hours, the body has half of that amount (so 1/4). Then after the third 6 hours the body has half of that amount (so 1/8). Then after the last 6 hours (since there are 4 6-hour periods in the 24-hour day), the body again has half of the previous amount (so 1/16).