Chapter 2, Problem 2.74QP

(a)

Interpretation Introduction

Interpretation:

The symbol of given element and number of protons and neutrons presented has to be identified.

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 2.74QP

The symbol of an element is $\text{Ne}$ which has 10 protons and 10 neutrons.

Explanation of Solution

Given unknown element is ${\text{X}}_{\text{10}}^{\text{20}}$ .

Where, an atomic number of this element is 10.  The element with atomic number of 10 is found as Neon.  Its proton and neutron is found as follows,

$\begin{array}{l}\text{Atomic number = 10 (proton number is equal to number of electrons)}\\ \text{Mass number = 20}\\ \text{No}\text{.of neutron}=\text{Mass number - No}\text{.of Protons }\\ \text{=}20-10\\ =10\end{array}$

(b)

Interpretation Introduction

Interpretation:

The symbol of given element and number of protons and neutrons presented has to be identified.

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 2.74QP

The symbol of an element is $\text{Cu}$ which has 29 protons and 34 neutrons.

Explanation of Solution

Given unknown element is ${\text{X}}_{29}^{63}$ .

Where, an atomic number of this element is 29.  The element with atomic number of 29 is found as Copper.  Its proton and neutron is found as follows,

$\begin{array}{l}\text{Atomic number = 29 (proton number is equal to number of electrons)}\\ \text{Mass number = 63}\\ \text{No}\text{.of neutron}=\text{Mass number - No}\text{.of Protons }\\ \text{=}63-29\\ =34\end{array}$

(c)

Interpretation Introduction

Interpretation:

The symbol of given element and number of protons and neutrons presented has to be identified.

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 2.74QP

The symbol of an element is $\text{Ag}$ which has 47 protons and 60 neutrons.

Explanation of Solution

Given unknown element is ${\text{X}}_{47}^{\text{107}}$ .

Where, an atomic number of this element is 47.  The element with atomic number of 47 is found as Silver.  Its proton and neutron is found as follows,

$\begin{array}{l}\text{Atomic number = 47 (proton number is equal to number of electrons)}\\ \text{Mass number = 107}\\ \text{No}\text{.of neutron}=\text{Mass number - No}\text{.of Protons }\\ \text{=}107-47\\ =60\end{array}$

(d)

Interpretation Introduction

Interpretation:

The symbol of given element and number of protons and neutrons presented has to be identified.

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 2.74QP

The symbol of an element is W which has 74 protons and 108 neutrons.

Explanation of Solution

Given unknown element is ${\text{X}}_{74}^{182}$ .

Where, an atomic number of this element is 74.  The element with atomic number of 74 is found as Tungsten.  Its proton and neutron is found as follows,

$\begin{array}{l}\text{Atomic number = 74 (proton number is equal to number of electrons)}\\ \text{Mass number = 182}\\ \text{No}\text{.of neutron}=\text{Mass number - No}\text{.of Protons }\\ \text{=}182-74\\ =108\end{array}$

(e)

Interpretation Introduction

Interpretation:

The symbol of given element and number of protons and neutrons presented has to be identified.

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 2.74QP

The symbol of an element is Polonium which has 84 protons and 119 neutrons.

Explanation of Solution

Given unknown element is ${\text{X}}_{84}^{\text{203}}$ .

Where, an atomic number of this element is 84.  The element with atomic number of 84 is found as Polonium.  Its proton and neutron is found as follows,

$\begin{array}{l}\text{Atomic number = 84 (Proton number is equal to number of electrons)}\\ \text{Mass number = 203}\\ \text{No}\text{.of neutron}=\text{Mass number - No}\text{.of Protons }\\ \text{=}203-84\\ =119\end{array}$

(f)

Interpretation Introduction

Interpretation:

The symbol of given element and number of protons and neutrons presented has to be identified.

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 2.74QP

The symbol of an element is Pu which has 94 protons and 140 neutrons.

Explanation of Solution

Given unknown element is ${\text{X}}_{94}^{\text{234}}$ .

Where, an atomic number of this element is 94.  The element with atomic number of 94 is found as Plutonium.  Its proton and neutron is found as follows,

$\begin{array}{l}\text{Atomic number = 94 (Proton number is equal to number of electrons)}\\ \text{Mass number = 234}\\ \text{No}\text{.of neutron}=\text{Mass number - No}\text{.of Protons }\\ \text{=}234-94\\ =140\end{array}$