Chapter 19, Problem 9STP

Interpretation Introduction

Interpretation: The transformation 2 in the figure has to be given.

Concept introduction: The decay of nucleus by emitting a beta $\left({\text{e}}^{\text{-}}\right)$ particle is called as beta emission. In beta emission, one neutron of the original nucleus decays to form a beta particle and a proton. Due to which, the new nucleus formed has one more proton and one fewer neutron than the original nucleus.

The general equation is given as,

  $X\to e+Y$

Answer to Problem 9STP

The transformation 2 in the figure is beta particle production. Option (B) is correct.

Explanation of Solution

The decay of nucleus by emitting a beta $\left({\text{e}}^{\text{-}}\right)$ particle is called as beta emission. In beta emission, one neutron of the original nucleus decays to form a beta particle and a proton. Due to which, the new nucleus formed has one more proton and one fewer neutron than the original nucleus.

The general equation is given as,

  $X\to e+Y$

Where,

• $A$is the mass number.
• $Z$is the atomic number.
• $X$ is the original isotope.
• $Y$is the new isotope.

In the transformation 2 from the figure, it can be observed that there is a change in the atomic number but the mass number remains unchanged.

It is seen that there is an increase in atomic number from $82$ to atomic number $83.$

The nuclear transformation in which the atomic number is increased by one unit with no change in the mass number is a beta-particle emission. Therefore, the transformation 2 in the figure is a beta-particle production.

Conclusion

The transformation 2 cannot be an alpha particle production because there is no change in mass number. In an alpha particle production, there would be decrease in the mass number by four units and decrease in the atomic number by two units. Hence, option (A) is incorrect.

The transformation 2 cannot be electron capture production because there is no decrease in atomic number by one unit. In electron capture process, the atomic number will be reduced by one unit and mass number would remain unchanged. Hence, option (C) is incorrect.