Chapter 25, Problem 62A

(a)

Interpretation Introduction

Interpretation:

The given word equation must be converted into a balanced nuclear equation.

Concept Interpretation:

The process of radioactive decay is how an unstable atomic nucleus loses energy through radiation. A substance that has unstable nuclei is regarded as radioactive.

Answer to Problem 62A

Nuclear equation converted from word equation: $Rn\to Po+He$ .

Explanation of Solution

Here, we have a decay of radon- $222$ into polonium- $218$ where we have alpha emission, and we need to look at both atomic and mass numbers and they need to be equal on both sides of the nuclear reaction (left and right from the arrow).

It is given that the nuclear particle on the right side that is emitted in the radioactive decay of isotope radon- $222$ is an alpha particle- helium nucleus $\text{H}\text{e}$ , and this particle has the mass number $\text{4}$ and the atomic number $\text{2}$ .

In the periodic table of elements, we can find the following symbols and atomic numbers for both isotopes:

Radon- $222$ $\to$ $Rn$

Polonium- $218$ $\to$ $Po$

The complete and balanced nuclear equation converted from the word equation is given as:

  $Rn\to Po+He$ .

(b)

Interpretation Introduction

Interpretation:

The given word equation must be converted into a balanced nuclear equation.

Concept Interpretation:

The process of radioactive decay is how an unstable atomic nucleus loses energy through radiation. A substance that has unstable nuclei is regarded as radioactive.

Answer to Problem 62A

Nuclear equation converted from word equation: $Th\to Ra+He$ .

Explanation of Solution

Here we have a decay of thorium- $234$ into radium- $230$ where we have alpha emission, and we need to look at both atomic and mass numbers and they need to be equal on both sides of the nuclear reaction (left and right from the arrow).

It is given that the nuclear particle on the right side that is emitted in the formation of isotope radium-230 is alpha particle - helium nucleus $He$ , and this particle has the mass number $4$ and the atomic number $2$ .

In the periodic table of elements, we can find the following symbols and atomic numbers for both isotopes:

Radium- $230$ $\to$ $Ra$

Thorium- $234$ $\to$ $Th$

The complete and balanced nuclear equation converted from the word equation is given as:

  $Th\to Ra+He$ .

(c)

Interpretation Introduction

Interpretation:

The given word equation must be converted into a balanced nuclear equation.

Concept Interpretation:

The process of radioactive decay is how an unstable atomic nucleus loses energy through radiation. A substance that has unstable nuclei is regarded as radioactive.

Answer to Problem 62A

Nuclear equation converted from word equation: $Po\to Pb+He$ .

Explanation of Solution

When $\left(\text{P}\text{o}\right)$ emits an alpha particle $\left(\text{H}\text{e}\right)$ it produces daughter nuclei with a mass decreased by two and an atomic number decreased by 4 which is Lead- $\left(\text{P}\text{b}\right)$

  $Po\to Pb+He$ .