Suppose a laboratory has a 31 g sample of polonium-210. The half-life of polonium-210 is about 138 days. a. How many half-lives of polonium-210 occur in 966 days? b. How much polonium is in the sample 966 days later?


7; 4.43 g

7; 2,139 g

7; 0.24 g

8; 0.12 g