Two radioactive substances A and B have the s | vedclass

Name: Exam Paper Generator | JEE NEET Paper Generator | Vedclass
Brand: Vedclass
Rating: 5 (35 reviews)

Question

(A) The number of nuclei remaining after time $t$ is given by $N = N_0 (1/2)^n$,where $n = t / T_{1/2}$ is the number of half-lives.For substance $A$:

Vedclass · Accepted Answer

$1: 16$

Vedclass · Answer

(A) The number of nuclei remaining after time $t$ is given by $N = N_0 (1/2)^n$,where $n = t / T_{1/2}$ is the number of half-lives.For substance $A$: $T_{1/2, A} = 1.5 \ days$,$t = 9 \ days$. Number of half-lives $n_A = 9 / 1.5 = 6$. Remaining nuclei $N_A = N_0 (1/2)^6 = N_0 / 64$.For substance $B$: $T_{1/2, B} = 4.5 \ days$,$t = 9 \ days$. Number of half-lives $n_B = 9 / 4.5 = 2$. Remaining nuclei $N_B = N_0 (1/2)^2 = N_0 / 4$.The ratio $N_A / N_B = (N_0 / 64) / (N_0 / 4) = 4 / 64 = 1 / 16$.Thus,the ratio is $1: 16$.

Two radioactive substances $A$ and $B$ have the same number of initial nuclei. If the half-lives of $A$ and $B$ are $1.5 \ days$ and $4.5 \ days$ respectively,then the ratio of the number of nuclei remaining in $A$ and $B$ after $9 \ days$ is

Similar Questions

Write the definition of half-life of a radioactive substance and obtain its relation to the decay constant.

$A$ radioactive substance decays to $\left(\frac{1}{16}\right)^{th}$ of its initial activity in $80\, days$. The half-life of the radioactive substance expressed in days is ... .

Activity of a radioactive substance is $R_1$ at time $t_1$ and $R_2$ at time $t_2$ $(t_2 > t_1)$. Then the ratio $\frac{R_2}{R_1}$ is:

$A$ $16\, g$ sample of a radioactive element is taken from Bombay to Delhi in $2\, hours$ and it is found that $1\, g$ of the element remains (undisintegrated). The half-life of the element is:

The half-life of a radioactive element is $30$ days. What percentage of the element will have decayed in $90$ days?

Vedclass Test Series

Exam Paper Generator

Online Exam Module