Embibe Experts Solutions for Chapter: Atoms and Nuclei, Exercise 1: Level 1

The half-life of${}_{92}^{238}\mathrm{U}$ undergoing $\alpha -$ decay is $4.5\times {10}^9$ $\mathrm{years}$. Calculate the activity of $1 \mathrm{g}$ sample of${}_{92}^{238}\mathrm{U}$. (Avogadro's number is $6.022\times {10}^{23}$)

A sample of a radioactive nucleus $A$ disintegrates to another radioactive nucleus $B,$ which in turn disintegrates to some other stable nucleus $C.$ Plot of a graph showing the variation of number of atoms of nucleus $B$ versus time is : (Assume that at $t=0,$ there are no $B$ atoms in the sample)

The half life period of a radioactive element $x$ is same as the mean life time of another radioactive element $y.$ Initially they have the same number of atoms. Then:

The ratio of amounts of radioactive substance $X$ and $Y$ at any instant is $1:4$. The half-life of substance $X$ is $18$ hours and of $Y$ is $12$ hours. After three days, the ratio of the amounts of the two substances will be

A nucleus with mass number $184$ initially at rest emits an $\alpha -$particle. If the $Q$ value of the reaction is $5.5 \mathrm{MeV},$ calculate the kinetic energy of the $\alpha -$ particle.

Which of the following statement is correct?

Which of the following nuclear reactions is possible?

When ${{}_{92}\mathrm{U}}^{235}$ undergoes fission, about $0.1\%$ of the original mass is converted into energy. The energy released when $1 \mathrm{kg}$ of ${{}_{92}\mathrm{U}}^{235}$ undergoes fission is