Question

the half life of a certain isotope is 8.5 hours. if we have a sample of 10 ounces of that isotope, how much of it will remain after one full day?

Answer 1

After 8.5 hours, there are 5 oz left, after another 8.5 hours, 2.5 oz are left. So, there are 7 hours left. 7/8.5=0.82. If we divide 2.5/2=1.25, then we multiply that by 0.82, and get 1.029. Then we add 1.25 to that to get 2.28. After a full day, there are about 2.28 ounces of the isotope left.