SOLUTION: A radioactive material has a half life of 3 hours. If after 8 hours there are 205g left, how many grams of material were there to begin with?

Algebra ->  Finance -> SOLUTION: A radioactive material has a half life of 3 hours. If after 8 hours there are 205g left, how many grams of material were there to begin with?      Log On


   

Question 1146977: A radioactive material has a half life of 3 hours. If after 8 hours there are 205g left, how many grams of material were there to begin with?
Answer by greenestamps(13200) About Me  (Show Source):
You can put this solution on YOUR website!


Working backward in time, the amount of material doubles every half-life.

8 hours is 8/3 half-lives.

The number of grams of material 8 hours ago was

205 * 2^(8/3)

Use a calculator....