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?

Which of the following are independent events? a) knowing that it is going to rain tomorrow, and bringing an umbrella to schoolb) knowing that you have to get up early tomorrow, and going to bed before 9 p.mc) knowing that it is going to rain tomorrow, and going to bed before 9 p.md) knowing that you have a test in school tomorrow, and studying thw night before