Half-lives of two radioactive elements A and B are 20 minutes and 40 minutes, respectively. Initially, the samples have equal number of nuclei. After 80 minutes, the ratio of decayed numbers of A and B nuclei will be :

Engineering

Physics

Radioactivity New

Question

1 : 4

5 : 4

1 : 16

4 : 1

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N_Decayed = No $(1 - e^{- \frac{t}{τ_{1 / 2}}})$

$\frac{N_{A}}{N_{B}} = \frac{5}{4}$