Chapter 2, Problem 107AE

(a)

Interpretation Introduction

Interpretation:

From the given data, the corresponding elements and the number of each nucleons has to be found.

Concept introduction:

The smallest constituent of matter is atom.  Each atom consist of subatomic particles called electrons, protons and neutrons.  Protons and neutrons are present in the nucleus and called nucleons.  A group of atoms having same number of protons are called as an element.

The atomic symbol for an element can be represented as ${}_{\text{Z}}^{\text{A}}\text{X}$

Where $\text{X}$ represents the symbol of the element, $\text{Z}$ represents the atomic number of the element and $\text{A}$ represents the atomic mass or mass number of the element.

Answer to Problem 107AE

The given element is found to be phosphorus

Number of protons $\text{=15}$

Number of neutrons $=16$

Explanation of Solution

Given, ${{}_{\text{15}}}^{\text{31}}\text{X}$

Atomic number, $\text{Z}\text{=15}$

Mass number, $\text{A}\text{=31}$

The atomic number of the element is equal to the number of protons.

The mass number  is equal to the sum of the number of protons and neutrons.

$\text{A}\text{=}\text{p+n}$

$\begin{array}{l}\text{Hence, the number of neutrons, n}\text{=}\text{31-15}\\ =16\end{array}$

The element with atomic number 15 was found to be phosphorus

${{}_{\text{15}}}^{\text{31}}\text{P}$

(b)

Interpretation Introduction

Interpretation:

From the given data, the corresponding elements and the number of each nucleons has to be found.

Concept introduction:

The smallest constituent of matter is atom.  Each atom consist of subatomic particles called electrons, protons and neutrons.  Protons and neutrons are present in the nucleus and called nucleons.  A group of atoms having same number of protons are called as an element.

The atomic symbol for an element can be represented as ${}_{\text{Z}}^{\text{A}}\text{X}$

Where $\text{X}$ represents the symbol of the element, $\text{Z}$ represents the atomic number of the element and $\text{A}$ represents the atomic mass or mass number of the element.

Answer to Problem 107AE

The given element is found to be potassium

Number of protons $\text{=19}$

Number of neutrons $=20$

Explanation of Solution

Given, ${{}_{\text{19}}}^{\text{39}}\text{X}$

Atomic number, $\text{Z}\text{=19}$

Mass number, $\text{A}\text{=39}$

The atomic number of the element is equal to the number of protons.

The mass number  is equal to the sum of the number of protons and neutrons.

$\text{A}\text{=}\text{p+n}$

$\begin{array}{l}\text{Hence, the number of neutrons, n}\text{=}\text{39-19}\\ =20\end{array}$

The element with atomic number 19 was found to be potassium

${{}_{\text{19}}}^{\text{39}}\text{K}$

(c)

Interpretation Introduction

Interpretation:

From the given data, the corresponding elements and the number of each nucleons has to be found.

Concept introduction:

The smallest constituent of matter is atom.  Each atom consist of subatomic particles called electrons, protons and neutrons.  Protons and neutrons are present in the nucleus and called nucleons.  A group of atoms having same number of protons are called as an element.

The atomic symbol for an element can be represented as ${}_{\text{Z}}^{\text{A}}\text{X}$

Where $\text{X}$ represents the symbol of the element, $\text{Z}$ represents the atomic number of the element and $\text{A}$ represents the atomic mass or mass number of the element.

Answer to Problem 107AE

The given element is found to be iodine

Number of protons $\text{=53}$

Number of neutrons $=74$

Explanation of Solution

Given, ${{}_{53}}^{127}\text{X}$

Atomic number, $\text{Z}\text{=53}$

Mass number, $\text{A}\text{=127}$

The atomic number of the element is equal to the number of protons.

The mass number  is equal to the sum of the number of protons and neutrons.

$\text{A}\text{=}\text{p+n}$

$\begin{array}{l}\text{Hence, the number of neutrons, n}\text{=}127\text{-53}\\ =74\end{array}$

The element with atomic number 15 was found to be iodine

${{}_{\text{127}}}^{\text{53}}\text{I}$

(d)

Interpretation Introduction

Interpretation:

From the given data, the corresponding elements and the number of each nucleons has to be found.

Concept introduction:

The smallest constituent of matter is atom.  Each atom consist of subatomic particles called electrons, protons and neutrons.  Protons and neutrons are present in the nucleus and called nucleons.  A group of atoms having same number of protons are called as an element.

The atomic symbol for an element can be represented as ${}_{\text{Z}}^{\text{A}}\text{X}$

Where $\text{X}$ represents the symbol of the element, $\text{Z}$ represents the atomic number of the element and $\text{A}$ represents the atomic mass or mass number of the element.

Answer to Problem 107AE

The given element is found to be ytterbium

Number of protons $\text{=70}$

Number of neutrons $=103$

Explanation of Solution

Given, ${{}_{70}}^{173}\text{X}$

Atomic number, $\text{Z}\text{=70}$

Mass number, $\text{A}\text{=173}$

The atomic number of the element is equal to the number of protons.

The mass number  is equal to the sum of the number of protons and neutrons.

$\text{A}\text{=}\text{p+n}$

$\begin{array}{l}\text{Hence, the number of neutrons, n}\text{=}173-70\\ =103\end{array}$

The element with atomic number 70 was found to be ytterbium

${{}_{\text{70}}}^{\text{173}}\text{Yb}$