Problema Solution
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
175
grams of a radioactive isotope, how much will be left after
4
half-lives?
Answer provided by our tutors
Start: 175 gr
After 1 half-life: (1/2)*175
After 2 half-lives: (1/2)(1/2)*175 = (1/2)^2 * 175
After 3 half-lives: (1/2)^3 * 175
After 4 half-lives: (1/2)^4 * 175 = 10.94 gr
After 4 half-lives there will be 10.94 gr radio-active isotope left.