WAEC - Physics (1992 - No. 55)
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
คำอธิบาย
\(\frac{N}{3}\) = 3years
\(\frac{N}{4}\) = 6years
\(\frac{N}{8}\) = 9years
N - \(\frac{N}{8}\) = \(\frac{7N}{8}\)
\(\frac{N}{4}\) = 6years
\(\frac{N}{8}\) = 9years
N - \(\frac{N}{8}\) = \(\frac{7N}{8}\)