An element whose half-life is 3 years has N atoms. How many atoms would have decayed after 9 years
- 1 N atoms8
- 1 N atoms3
- 2 N atoms3
- 5 N atoms6
-
7 N atoms8
The correct answer is: E
Explanation
\(\frac{N}{3}\) = 3years\(\frac{N}{4}\) = 6years
\(\frac{N}{8}\) = 9years
N - \(\frac{N}{8}\) = \(\frac{7N}{8}\)