Question

If the half life of a radioactive

substance is 5.3 years and there are
8.4 grams present initially, when will
there be 1 gram remaining?
[?] years
Use the function f(t) = Pert and round
your answer to the nearest year.
Enter

Answer 1

Ok so half life problems have their own separate equation which is (Initial grams)(0.5)^(time/half life)
So in this equation you would get 8.4 *(0.5)^ t/5.3
So if you have access to a graphing calculator you could graph it and get approximately 16.25 years or you could go by half life’s and say after one cycle it will be 4.2
After two cycles it will be 2.1 after 3 cycles it will be 1.05 which rounds to one. Now take your cycles and multiple by 5.3 per cycle to get approximately 16