If 96.875 % of a radioactive substance decays | vedclass

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

Question

(D) The amount of radioactive substance remaining after decay is $N = N_0 - 0.96875 N_0 = 0.03125 N_0$.We know that $N = N_0 (1/2)^n$,where $n$ is the

Vedclass · Accepted Answer

$2$

Vedclass · Answer

(D) The amount of radioactive substance remaining after decay is $N = N_0 - 0.96875 N_0 = 0.03125 N_0$.We know that $N = N_0 (1/2)^n$,where $n$ is the number of half-lives.$0.03125 N_0 = N_0 (1/2)^n$$0.03125 = (1/2)^n$Since $0.03125 = 1/32 = (1/2)^5$,we have $n = 5$.The total time $t$ is related to the number of half-lives $n$ and half-life $T_{1/2}$ by $t = n 	imes T_{1/2}$.Given $t = 10 	ext{ days}$ and $n = 5$,we have $10 = 5 	imes T_{1/2}$.Therefore,$T_{1/2} = 10 / 5 = 2 	ext{ days}$.

If $96.875 \%$ of a radioactive substance decays in $10 \text{ days}$,then the half life of the substance is (in days)

Similar Questions

If a radioactive element having a half-life of $30 \ min$ is undergoing beta decay,the fraction of the radioactive element that remains undecayed after $90 \ min$ will be:

The half-life of radium is about $1600$ years. Of $100 \, g$ of radium existing now, $25 \, g$ will remain unchanged after .......... $years$.

The half-life of a radioactive element depends upon:

Half-life of a radioactive substance is $20 \ min$. The difference between the points of time when it is $33\%$ disintegrated and $67\%$ disintegrated is approximately ........... $min$.

$A$ radioactive sample at any instant has its disintegration rate $5000$ disintegrations per minute. After $5\, minutes$,the rate becomes $1250$ disintegrations per minute. Then,its decay constant (per minute) is

Vedclass Test Series

Exam Paper Generator

Online Exam Module