Chapter 2, Problem 2.39QE

(a)

Interpretation Introduction

Interpretation:

Symbol of atom or ion has to be written that has 12 protons, 13 neutrons, and 10 electrons.

Concept Introduction:

Each and every element present in the Periodic table has a unique name.  Some of the elements are named considering their atomic number.  In order to represent the elements in a short form, atomic symbols are used.  Generally the first two letters of the element name will be used as symbol where the first letter is in upper case.

Chemical names are represented as atomic symbols.  In the symbols, the mass number and atomic number are shown.  The complete symbol for an element can be represented as shown below.

Atomic number is the total number of protons present in the atom of an element.  Mass number is the total number of protons and neutrons present in nucleus of an atom.

Explanation of Solution

The species is said to contain 12 protons, 13 neutrons, and 10 electrons.  Atomic number is equal to the number of protons and mass number is equal to the sum of protons and neutrons.  Atomic number and mass number can be given as shown below.

    $\begin{array}{c}\text{Atomic}\text{number}=\text{Number}\text{of}\text{protons}\\ =12\\ \text{Mass}\text{number}=\text{Number}\text{of}\text{protons+Number}\text{of}\text{neutrons}\\ =12+13\\ =25\end{array}$

The charge on the ion can be calculated considering the number of protons and electrons as shown below.

    $\begin{array}{c}\text{Charge}=\text{Number}\text{of}\text{protons}-\text{Number}\text{of}\text{electrons}\\ \text{=12}-10\\ =+2\end{array}$

Element with the atomic number of 12 is magnesium.  The atomic symbol of ion can be given as $\text{M}{\text{g}}^{2+}$.

(b)

Interpretation Introduction

Interpretation:

Symbol of atom or ion has to be written that has 13 protons, 14 neutrons, and 10 electrons.

Concept Introduction:

Refer part (a).

Explanation of Solution

The species is said to contain 13 protons, 14 neutrons, and 10 electrons.  Atomic number is equal to the number of protons and mass number is equal to the sum of protons and neutrons.  Atomic number and mass number can be given as shown below.

    $\begin{array}{c}\text{Atomic}\text{number}=\text{Number}\text{of}\text{protons}\\ =13\\ \text{Mass}\text{number}=\text{Number}\text{of}\text{protons+Number}\text{of}\text{neutrons}\\ =13+14\\ =27\end{array}$

The charge on the ion can be calculated considering the number of protons and electrons as shown below.

    $\begin{array}{c}\text{Charge}=\text{Number}\text{of}\text{protons}-\text{Number}\text{of}\text{electrons}\\ \text{=13}-10\\ =+3\end{array}$

Element with the atomic number of 13 is aluminium.  The atomic symbol of ion can be given as $\text{A}{\text{l}}^{3+}$.

(c)

Interpretation Introduction

Interpretation:

Symbol of atom or ion has to be written that has 14 protons, 15 neutrons, and 14 electrons.

Concept Introduction:

Refer part (a).

Explanation of Solution

The species is said to contain 14 protons, 15 neutrons, and 14 electrons.  Atomic number is equal to the number of protons and mass number is equal to the sum of protons and neutrons.  Atomic number and mass number can be given as shown below.

    $\begin{array}{c}\text{Atomic}\text{number}=\text{Number}\text{of}\text{protons}\\ =14\\ \text{Mass}\text{number}=\text{Number}\text{of}\text{protons+Number}\text{of}\text{neutrons}\\ =14+15\\ =29\end{array}$

The charge on the ion can be calculated considering the number of protons and electrons as shown below.

    $\begin{array}{c}\text{Charge}=\text{Number}\text{of}\text{protons}-\text{Number}\text{of}\text{electrons}\\ \text{=14}-14\\ =0\end{array}$

As the charge is zero, it is an atom and not an ion.

Element with the atomic number of 14 is silicon.  The atomic symbol of atom can be given as $\text{S}\text{i}$.

(d)

Interpretation Introduction

Interpretation:

Symbol of atom or ion has to be written that has 35 protons, 44 neutrons, and 36 electrons.

Concept Introduction:

Refer part (a).

Explanation of Solution

The species is said to contain 35 protons, 44 neutrons, and 36 electrons.  Atomic number is equal to the number of protons and mass number is equal to the sum of protons and neutrons.  Atomic number and mass number can be given as shown below.

    $\begin{array}{c}\text{Atomic}\text{number}=\text{Number}\text{of}\text{protons}\\ =35\\ \text{Mass}\text{number}=\text{Number}\text{of}\text{protons+Number}\text{of}\text{neutrons}\\ =35+44\\ =79\end{array}$

The charge on the ion can be calculated considering the number of protons and electrons as shown below.

    $\begin{array}{c}\text{Charge}=\text{Number}\text{of}\text{protons}-\text{Number}\text{of}\text{electrons}\\ \text{=35}-36\\ =-1\end{array}$

Element with the atomic number of 35 is bromine.  The atomic symbol of ion can be given as $\text{B}{\text{r}}^{-1}$.