Question

Bismuth-210 has a half-life of 5 days. Find

the amount of Bismuth-210 left from a
100-gram sample after 5 weeks?

Answer 1

0.78125g

Explanation:

Since there are 35 days in 5 weeks, 7 half-lives of Bismuth-210 will take place. To solve for that, you can divide 100g by 2, 7 times or simply:
`(100)/(2^(7))`

`(100)/(2) =50\\(50)/(2) =25\\(25)/(2) =12.5\\(12.5)/(2) =6.25\\(6.25)/(2) =3.125\\(3.125)/(2) =1.5625\\(1.5625)/(2) =0.78125`