Number of undecayed nuclei present at time t is
N=N0e−λt, here N0 is the number of radioactive nuclei in sample at time t=0.
So for A,NA=N0e−8λt
for B,NB=N0e−λt
given NBNA=e1
Then
NBNA=N0e−λtN0e−8λt
e1=e−7λt
−1=−7λt
t=7λ1
Radioactive material A has decay constant 8λ and material B has decay constant λ. Initially they have the same number of nuclei. After what time, the ratio of number of nuclei of material A to that B will be e1?
Held on 30 Apr 2017 · Verified 9 Jul 2026.
λ1
7λ1
8λ1
9λ1
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