Chapter 2, Problem 2.68QP

A

Interpretation Introduction

Interpretation:

The symbols for each atom has to be identified.

Concept Introduction:

Conversion of atoms to moles: $\text{no}\text{.of moles = }\frac{\text{no}\text{.of atoms}}{\text{Avogadro's number}}.$

Nuclear stability: The nucleus is composed of protons and neutrons.  The strongest nuclear force binds the particles tightly.  Though the protons repel each other due to no attraction between similar charges, possess short-range attractions made the attraction possible between proton and proton, proton and neutron, neutron and neutron.

The stability of any element is determined by the difference between columbic repulsion and the short-range attraction.  If repulsion outweighs the attraction, the disintegration of nucleus occurs by producing the daughter nuclides.  If the attractive forces prevail, the nucleus is stable.

Answer to Problem 2.68QP

The symbol for given atom is $\text{C}$

Explanation of Solution

To Identify: The symbols for each atom to be identified.

$\begin{array}{l}{\text{The element symbol : }}_{\text{Z}}^{\text{A}}\text{X,}\\ \text{where, A (mass number) = no}\text{.of protons + no}\text{.of neutrons}\text{.}\\ \text{ Z (atomic number) = no}\text{. of protons}\text{. (electrons = protons)}\text{.}\end{array}$

$\begin{array}{l}{\text{The element symbol : }}_{\text{Z}}^{\text{A}}\text{X,}\\ \text{Z (atomic number) = no}\text{. of protons}\text{. (protons = electrons)}\\ \text{= 6}\text{.}\\ \text{A (mass number) = no}\text{.of protons + no}\text{.of neutrons}\text{.}\\ \text{ = 6 + 6 = 12}\\ {\text{The symbol: }}_6^{12}\text{C}\text{.}\end{array}$

The number of electron is equal to the number proton in the nucleus, thus the $\text{6}$ electrons is same as $\text{6}$ protons. The sum of protons and neutrons in the nucleus give the mass number of an element. The atomic number $\text{6}$ indicates the element is Carbon. The represented symbol is ${}_6^{12}\text{C}$.

B

Interpretation Introduction

Interpretation:

The symbols for each atom has to be identified.

Concept Introduction:

Conversion of atoms to moles: $\text{no}\text{.of moles = }\frac{\text{no}\text{.of atoms}}{\text{Avogadro's number}}.$

Nuclear stability: The nucleus is composed of protons and neutrons.  The strongest nuclear force binds the particles tightly.  Though the protons repel each other due to no attraction between similar charges, possess short-range attractions made the attraction possible between proton and proton, proton and neutron, neutron and neutron.

The stability of any element is determined by the difference between columbic repulsion and the short-range attraction.  If repulsion outweighs the attraction, the disintegration of nucleus occurs by producing the daughter nuclides.  If the attractive forces prevail, the nucleus is stable.

Answer to Problem 2.68QP

The symbol for given atom is $\text{N}\text{a}$

Explanation of Solution

To Identify: The symbols for each atom to be identified.

Identify the symbol of an element.

$\begin{array}{l}{\text{The element symbol : }}_{\text{Z}}^{\text{A}}\text{X,}\\ \text{where, A (mass number) = no}\text{.of protons + no}\text{.of neutrons}\text{.}\\ \text{ Z (atomic number) = no}\text{. of protons}\text{. (electrons = protons)}\text{.}\end{array}$

$\begin{array}{l}{\text{The element symbol : }}_{\text{Z}}^{\text{A}}\text{X,}\\ \text{Z (atomic number) = no}\text{. of protons}\text{. (protons = electrons)}\\ \text{= 11}\text{.}\\ \text{A (mass number) = no}\text{.of protons + no}\text{.of neutrons}\text{.}\\ \text{ = 11 + 7 = 18}\text{.}\\ {\text{The symbol: }}_{11}^{18}\text{Na}\text{.}\end{array}$

The number of electron is equal to the number proton in the nucleus, thus the $\text{11}$ electrons is same as $\text{11}$ protons. The sum of protons and neutrons in the nucleus give the mass number of an element. The atomic number $\text{11}$ indicates the element is Sodium. The represented symbol is ${}_{11}^{18}\text{Na}$.

C

Interpretation Introduction

Interpretation:

The symbols for each atom has to be identified.

Concept Introduction:

Conversion of atoms to moles: $\text{no}\text{.of moles = }\frac{\text{no}\text{.of atoms}}{\text{Avogadro's number}}.$

Nuclear stability: The nucleus is composed of protons and neutrons.  The strongest nuclear force binds the particles tightly.  Though the protons repel each other due to no attraction between similar charges, possess short-range attractions made the attraction possible between proton and proton, proton and neutron, neutron and neutron.

The stability of any element is determined by the difference between columbic repulsion and the short-range attraction.  If repulsion outweighs the attraction, the disintegration of nucleus occurs by producing the daughter nuclides.  If the attractive forces prevail, the nucleus is stable.

Answer to Problem 2.68QP

No neutrons number is given. No symbol is determined.

Explanation of Solution

To Identify: The symbols for each atom to be identified.

Identify the symbol of an element.

$\begin{array}{l}{\text{The element symbol : }}_{\text{Z}}^{\text{A}}\text{X,}\\ \text{where, A (mass number) = no}\text{.of protons + no}\text{.of neutrons}\text{.}\\ \text{ Z (atomic number) = no}\text{. of protons}\text{. (electrons = protons)}\text{.}\end{array}$

$\begin{array}{l}{\text{The element symbol : }}_{\text{Z}}^{\text{A}}\text{X,}\\ \text{Z (atomic number) = no}\text{. of protons}\text{. (protons = electrons)}\\ \text{= 29}\text{.}\\ \text{A (mass number) = no}\text{.of protons + no}\text{.of neutrons}\text{.}\\ \text{ = 29 + no neutron value is given}\text{.}\\ \text{The symbol cannot be predicted without the mass number(no number of neutronis given)}\text{.}\end{array}$

The number of electron is equal to the number proton in the nucleus, thus the $\text{29}$ electrons is same as $\text{29}$ protons. The sum of protons and neutrons in the nucleus give the mass number of an element. The element symbol cannot be predicted without the mass number because number of neutrons is not given.

D

Interpretation Introduction

Interpretation:

The symbols for each atom has to be identified.

Concept Introduction:

Conversion of atoms to moles: $\text{no}\text{.of moles = }\frac{\text{no}\text{.of atoms}}{\text{Avogadro's number}}.$

Nuclear stability: The nucleus is composed of protons and neutrons.  The strongest nuclear force binds the particles tightly.  Though the protons repel each other due to no attraction between similar charges, possess short-range attractions made the attraction possible between proton and proton, proton and neutron, neutron and neutron.

The stability of any element is determined by the difference between columbic repulsion and the short-range attraction.  If repulsion outweighs the attraction, the disintegration of nucleus occurs by producing the daughter nuclides.  If the attractive forces prevail, the nucleus is stable.

Answer to Problem 2.68QP

The symbol for given atom is $\text{K}\text{r}$

Explanation of Solution

To Identify: The symbols for each atom to be identified.

Identify the symbol of an element.

$\begin{array}{l}{\text{The element symbol : }}_{\text{Z}}^{\text{A}}\text{X,}\\ \text{where, A (mass number) = no}\text{.of protons + no}\text{.of neutrons}\text{.}\\ \text{ Z (atomic number) = no}\text{. of protons}\text{. (electrons = protons)}\text{.}\end{array}$

$\begin{array}{l}{\text{The element symbol : }}_{\text{Z}}^{\text{A}}\text{X,}\\ \text{Z (atomic number) = no}\text{. of protons}\text{. (protons = electrons)}\\ \text{= 36}\text{.}\\ \text{A (mass number) = no}\text{.of protons + no}\text{.of neutrons}\text{.}\\ \text{ = 36 + 47 = 83}\text{.}\\ {\text{The symbol: }}_{36}^{83}\text{Kr}\text{.}\end{array}$

The number of electron is equal to the number proton in the nucleus, thus the $\text{36}$ electrons is same as $\text{36}$ protons. The sum of protons and neutrons in the nucleus give the mass number of an element. The atomic number $\text{36}$ indicates the element is Krypton. The represented symbol is ${}_{36}^{83}\text{Kr}$.