Chapter 2, Problem 2.38QP

Write the correct symbols for the atoms that contain: (a) 25 protons, 25 electrons, and 27 neutrons; (b) 10 protons, 10 electrons, and 12 neutrons; (c) 47 protons, 47 electrons, and 60 neutrons; (d) 53 protons, 53 electrons, and 74 neutrons; (e) 94 protons, 94 electrons, and 145 neutrons.

Interpretation Introduction

Interpretation:

Correct symbol for the atoms contains 25 protons, 25 electrons and 27 neutrons has to be written.

Concept Introduction:

Mass number (A): Mass number of an element is sum of protons and neutrons of the atom.

$\text{A= Number of protons}\left(\text{P}\right)\text{ + Number of neutrons}\left(\text{n}\right)$

Consider an element X with atomic number and mass number,

${}_Z^A\text{X}$

Where,

A is mass number and Z is atomic number (number of proton or electron)

Answer to Problem 2.38QP

The symbol for given atom is found as ${\text{Mn}}_{\text{25}}^{\text{52}}$.

Explanation of Solution

Given:

Number of protons: 25

Number of neutrons: 27

Number of electrons: 25

$\begin{array}{l}\text{Z (atomic number) = No}\text{. of protons (protons = electrons)}\\ \text{= 25}\\ \text{A (mass number) = no}\text{.of protons (P) + No}\text{.of neutrons (N)}\text{.}\\ \text{ = 25+27 }\\ \text{= 52 }\end{array}$

The atomic number 25 represents the element Manganese.  The sum of protons and neutrons in the nucleus give the mass number of an element.  Hence, the symbol is ${\text{Mn}}_{\text{25}}^{\text{52}}$.

Interpretation Introduction

Interpretation:

Correct symbol for the atoms contains 10 protons, 10 electrons and 12 neutrons has to be written.

Concept Introduction:

Mass number (A): Mass number of an element is sum of protons and neutrons of the atom.

$\text{A= Number of protons}\left(\text{P}\right)\text{ + Number of neutrons}\left(\text{n}\right)$

Consider an element X with atomic number and mass number,

${}_Z^A\text{X}$

Where,

A is mass number and Z is atomic number (number of proton or electron)

Answer to Problem 2.38QP

The symbol for given atom is found as ${\text{Ne}}_{\text{10}}^{\text{22}}$.

Explanation of Solution

Given:

Number of protons: 10

Number of neutrons: 12

Number of electrons: 10

$\begin{array}{l}\text{Z (atomic number) = No}\text{. of protons (protons = electrons)}\\ \text{= 10}\\ \text{A (mass number) = no}\text{.of protons (P) + No}\text{.of neutrons (N)}\text{.}\\ \text{ = 10 +12}\\ \text{= 22 }\end{array}$

The atomic number 10 represents the element Neon.  The sum of protons and neutrons in the nucleus give the mass number of an element.  Hence, the symbol is ${\text{Ne}}_{\text{10}}^{\text{22}}$.

Interpretation Introduction

Interpretation:

Correct symbol for the atoms contains 47 protons, 47 electrons and 60 neutrons has to be written.

Concept Introduction:

Mass number (A): Mass number of an element is sum of protons and neutrons of the atom.

$\text{A= Number of protons}\left(\text{P}\right)\text{ + Number of neutrons}\left(\text{n}\right)$

Consider an element X with atomic number and mass number,

${}_Z^A\text{X}$

Where,

A is mass number and Z is atomic number (number of proton or electron)

Answer to Problem 2.38QP

The symbol for given atom is found as ${\text{Ag}}_{\text{47}}^{\text{107}}$.

Explanation of Solution

Given:

Number of protons: 47

Number of neutrons: 60

Number of electrons: 47

$\begin{array}{l}\text{Z (atomic number) = No}\text{. of protons (protons = electrons)}\\ \text{= 47}\\ \text{A (mass number) = no}\text{.of protons (P) + No}\text{.of neutrons (N)}\text{.}\\ \text{ = 47+60 }\\ \text{= 107 }\end{array}$

The atomic number 47 represents the element Silver.  The sum of protons and neutrons in the nucleus give the mass number of an element.  Hence, the symbol is ${\text{Ag}}_{\text{47}}^{\text{107}}$.

Interpretation Introduction

Interpretation:

Correct symbol for the atoms contains 53 protons, 53 electrons and 74 neutrons has to be written.

Concept Introduction:

Mass number (A): Mass number of an element is sum of protons and neutrons of the atom.

$\text{A= Number of protons}\left(\text{P}\right)\text{ + Number of neutrons}\left(\text{n}\right)$

Consider an element X with atomic number and mass number,

${}_Z^A\text{X}$

Where,

A is mass number and Z is atomic number (number of proton or electron)

Answer to Problem 2.38QP

The symbol for given atom is found as ${\text{I}}_{\text{53}}^{\text{127}}$.

Explanation of Solution

Given:

Number of protons: 53

Number of neutrons: 74

Number of electrons: 53

$\begin{array}{l}\text{Z (atomic number) = No}\text{. of protons (protons = electrons)}\\ \text{= 53}\\ \text{A (mass number) = no}\text{.of protons (P) + No}\text{.of neutrons (N)}\text{.}\\ \text{ = 53+74}\\ \text{= 127 }\end{array}$

The atomic number 53 represents the element Iodine.  The sum of protons and neutrons in the nucleus give the mass number of an element.  Hence, the symbol is ${\text{I}}_{\text{53}}^{\text{127}}$.

Interpretation Introduction

Interpretation:

Correct symbol for the atoms contains 94 protons, 94 electrons and 145 neutrons has to be written.

Concept Introduction:

Mass number (A): Mass number of an element is sum of protons and neutrons of the atom.

$\text{A= Number of protons}\left(\text{P}\right)\text{ + Number of neutrons}\left(\text{n}\right)$

Consider an element X with atomic number and mass number,

${}_Z^A\text{X}$

Where,

A is mass number and Z is atomic number (number of proton or electron)

Answer to Problem 2.38QP

The symbol for given atom is found as ${\text{Pu}}_{\text{94}}^{\text{239}}$.

Explanation of Solution

Given:

Number of protons: 94

Number of neutrons: 145

Number of electrons: 94

$\begin{array}{l}\text{Z (atomic number) = No}\text{. of protons (protons = electrons)}\\ \text{= 94}\\ \text{A (mass number) = no}\text{.of protons (P) + No}\text{.of neutrons (N)}\text{.}\\ \text{ = 94+145}\\ \text{= 239 }\end{array}$

The atomic number 94 represents the element Plutonium.  The sum of protons and neutrons in the nucleus give the mass number of an element.  Hence, the symbol is ${\text{Pu}}_{\text{94}}^{\text{239}}$.