Question

A radioactive sample is decayed 20% in one day. After next two days, the undecayed percentage of nuclei will be? ​

Answer 1

Answer:

Explanation:

=> Here, A radioactive sample is decayed 20% in one day, that means N = nuclei left = 80 %

=> Now, N = N₀ e^-λt

80/100 = e^-λ

-ln(8/10) = λ

=> decayed percentage of nuclei in next two days:

N = N₀ e^-λt

N = N₀ e^ln(8/10) * 2

   = N₀ e^2ln(8/10)

   = N₀ e^ln(8/10)^2

   =N₀ * 64/100

   = 64 %  

=> Hence, undecayed percentage of nuclei :

100 - 64% = 36 %

=> Thus, after next two days the undecayed percentage of nuclei will be 36%.