Chapter 19, Problem 10STP

Interpretation Introduction

Interpretation:The transformation 1 in the figure has to be given.

Concept introduction:The decay of a nucleus by emitting an alpha particle $\left(\alpha \left(or\right)\text{H}\text{e}\right)$ is called as alpha emission. The general balanced equation is,

  $X\to \alpha +Y$

Answer to Problem 10STP

The transformation 1 in the figure is alpha particle production. Option (A) is correct.

Explanation of Solution

The decay of a nucleus by emitting an alpha particle $\left(\alpha \left(or\right)\text{H}\text{e}\right)$ is called alpha emission. The general balanced equation is,

  $X\to \alpha +Y$

Where,

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

Since the alpha particle consists of two protons, the newly formed nucleus has two fewer protons than the original nucleus. Because it has a different number of neutrons, the new nucleus represents a different element.

In the transformation 1 from the figure, it can be observed that there is a change in the atomic number and change in the mass number.

It is seen that there is adecrease in atomic number from $84$ to $82.$

In addition, the mass number is decreased from $214$ to $\text{210}\text{.}$

The nuclear transformation in which the atomic number decreases by two units and the mass number decreases by four units is analpha-particle emission. Therefore, transformation 1 in the figure is analpha-particle production.

Conclusion

The transformation 1 cannot be a beta particle production because there is a change in mass number and atomic number. In a beta particle production, there would be no change in the mass number and the atomic number would be increased by one unit. Hence, option (B) is incorrect.

The transformation 1 cannot be electron capture production because there is a change in mass number and atomic number. In the electron capture process, the atomic number is reduced by one unit and the mass number would remain unchanged. Hence, option (C) is incorrect.