Chapter 2, Problem 2.52P

(a)

Interpretation Introduction

Interpretation:Name of the parent atom, its mass number and its group and period numbers of below mentioned ionic depiction should be given.

  

Concept introduction:Total number of protons in an element is known as its atomic number and it is represented with symbol $\left(\text{Z}\right)$ . Also in any atom has equal number of protons and electrons to maintain its electrical neutrality. Mass number $\left(\text{A}\right)$ of any isotope of an element is determined by the addition of its atomic number $\left(\text{Z}\right)$ with its neutron number $\left(\text{N}\right)$ .

Formula to calculate the mass number $\left(\text{A}\right)$ from neutron number $\left(\text{N}\right)$ , and its atomic number $\left(\text{Z}\right)$ is as follows:

  $\text{Mass number}\left(\text{A}\right)=\text{Neutron number}\left(\text{N}\right)+\text{Atomic number}\left(\text{Z}\right)$

To calculate the group number of the atom, we have to consider its electronic configuration.

Formula to calculate the period number of an atom is as follows:

  $\text{period}\text{number}=\left(\begin{array}{l}\text{principle}\text{quantum}\\ \text{number}\text{of}\text{valence shell}\end{array}\right)$

Formula to calculate the groupnumber of s-block elements are as follows:

  $\text{Number}\text{of}\text{group}=\text{Number}\text{of}\text{electrons}\text{in}\text{last}\text{s}\text{subshell}$

Formula to calculate the groupnumber of p-block elements are as follows:

  $\text{Number}\text{of}\text{group}=\left(12+\text{Number}\text{of}\text{electrons}\text{in}\text{last}\text{p}\text{subshell}\right)$

Formula to calculate the groupnumber of d-block elements are as follows:

  $\text{Number}\text{of}\text{group}=\left(2+\text{Number}\text{of}\text{electrons}\text{in}\text{last}\text{d}\text{subshell}\right)$

Inert gases are placed in group number 18 in the modern periodic table.

Explanation of Solution

Number of protons in the ionic depiction is 8. Hence its atomic number is 8. So the parent atom is oxygen $\left(\text{O}\right)$ .

Formula to calculate the mass number $\left(\text{A}\right)$ of oxygen from neutron number $\left(\text{N}\right)$ of oxygen, and its atomic number $\left(\text{Z}\right)$ is as follows:

  $\text{Mass number}\left(\text{A}\right)\text{of}\text{oxygen}=\left(\begin{array}{l}\text{Neutron number}\left(\text{N}\right)\text{of}\text{oxygen}+\\ \text{Atomic number}\left(\text{Z}\right)\text{of}\text{oxygen}\end{array}\right)$

Atomic number of oxygen is 8.

Neutron number of oxygen is 9.

Substitute the values in above formula.

  $\begin{array}{c}\text{Mass number}\left(\text{A}\right)\text{of}\text{oxygen}=\left(\begin{array}{l}\text{Neutron number}\left(\text{N}\right)\text{of}\text{oxygen}+\\ \text{Atomic number}\left(\text{Z}\right)\text{of}\text{oxygen}\end{array}\right)\\ =9+8\\ =17\end{array}$

Number electrons present in the parent atom of the atomic depiction is equal to its atomic number, that is equal to 8. Hence electronic configuration will be $1{\text{s}}^{2}2{\text{s}}^{2}2{\text{p}}^4$ . As last electron of oxygen is in $2\text{p}$ subshell so oxygen is a $\text{p}$ block element.

Formula to calculate the period number of oxygen is as follows:

  $\text{period}\text{number of oxygen}=\left(\begin{array}{l}\text{principle}\text{quantum}\text{number}\\ \text{of}\text{valence shell of oxygen}\end{array}\right)$

Principle quantum number of valance shell of oxygen is 2.

Substitute the values in the above formula.

  $\begin{array}{c}\text{period}\text{number of oxygen}=\left(\begin{array}{l}\text{principle}\text{quantum}\text{number}\\ \text{of}\text{valence shell of oxygen}\end{array}\right)\\ =2\end{array}$

Formula to calculate the group number of p-block element oxygen is as follows:

  $\text{Number}\text{of}\text{group}=\left(12+\text{Number}\text{of}\text{electrons}\text{in}\text{last}\text{p}\text{subshell of oxygen}\right)$

Number of electrons in last $\text{p}$ subshell of oxygen is 4.

Substitute the value in the above formula.

  $\begin{array}{c}\text{Number}\text{of}\text{group}=\left(12+\text{Number}\text{of}\text{electrons}\text{in}\text{last}\text{p}\text{subshell of oxygen}\right)\\ =12+4\\ =16\end{array}$

(b)

Interpretation Introduction

Interpretation: Name of the parent atom, its mass number and its group and period numbers of bellow mentioned ionic depiction should be given.

  

Concept introduction:Total number of protons in an element is known as its atomic number and it is represented with symbol $\left(\text{Z}\right)$ . Also in any atom has equal number of protons and electrons to maintain its electrical neutrality. Mass number $\left(\text{A}\right)$ of any isotope of an element is determined by the addition of its atomic number $\left(\text{Z}\right)$ with its neutron number $\left(\text{N}\right)$ .

Formula to calculate the mass number $\left(\text{A}\right)$ from neutron number $\left(\text{N}\right)$ , and its atomic number $\left(\text{Z}\right)$ is as follows:

  $\text{Mass number}\left(\text{A}\right)=\text{Neutron number}\left(\text{N}\right)+\text{Atomic number}\left(\text{Z}\right)$

To calculate the group number of the atom, we have to consider its electronic configuration.

Formula to calculate the period number of an atom is as follows:

  $\text{period}\text{number}=\left(\begin{array}{l}\text{principle}\text{quantum}\\ \text{number}\text{of}\text{valence shell}\end{array}\right)$

Formula to calculate the group number of s-block elements are as follows:

  $\text{Number}\text{of}\text{group}=\text{Number}\text{of}\text{electrons}\text{in}\text{last}\text{s}\text{subshell}$

Formula to calculate the group number of p-block elements are as follows:

  $\text{Number}\text{of}\text{group}=\left(12+\text{Number}\text{of}\text{electrons}\text{in}\text{last}\text{p}\text{subshell}\right)$

Formula to calculate the group number of d-block elements are as follows:

  $\text{Number}\text{of}\text{group}=\left(2+\text{Number}\text{of}\text{electrons}\text{in}\text{last}\text{d}\text{subshell}\right)$

Inert gases are placed in group number 18 in the modern periodic table.

Explanation of Solution

Number of protons in the ionic depiction is 9. Hence its atomic number is 9. So the parent atom is fluorine $\left(\text{F}\right)$ .

Formula to calculate the mass number $\left(\text{A}\right)$ of fluorine from neutron number $\left(\text{N}\right)$ of fluorine, and its atomic number $\left(\text{Z}\right)$ is as follows:

  $\text{Mass number}\left(\text{A}\right)\text{of}\text{fluorine}=\left(\begin{array}{l}\text{Neutron number}\left(\text{N}\right)\text{of}\text{fluorine}+\\ \text{Atomic number}\left(\text{Z}\right)\text{of}\text{fluorine}\end{array}\right)$

Atomic number of fluorine is 9.

Neutron number of fluorine is 10.

Substitute the values in the above formula.

  $\begin{array}{c}\text{Mass number}\left(\text{A}\right)\text{of}\text{fluorine}=\left(\begin{array}{l}\text{Neutron number}\left(\text{N}\right)\text{of}\text{fluorine}+\\ \text{Atomic number}\left(\text{Z}\right)\text{of}\text{fluorine}\end{array}\right)\\ =10+9\\ =19\end{array}$

Number electrons present in the parent atom of the atomic depiction is equal to its atomic number, that is 9. Hence electronic configuration will be $1{\text{s}}^{2}2{\text{s}}^{2}2{\text{p}}^5$ . As last electron of fluorine is in $2\text{p}$ subshell so fluorine is a $\text{p}$ block element.

Formula to calculate the period number of fluorine is as follows:

  $\text{period}\text{number of fluorine}=\left(\begin{array}{l}\text{principle}\text{quantum}\text{number}\\ \text{of}\text{valence shell of fluorine}\end{array}\right)$

Principle quantum number of valance shell of fluorine is 2.

Substitute the values in the above formula.

  $\begin{array}{c}\text{Period}\text{number of fluorine}=\left(\begin{array}{l}\text{principle}\text{quantum}\text{number}\\ \text{of}\text{valence shell of fluorine}\end{array}\right)\\ =2\end{array}$

Formula to calculate the groupnumber of p-block element fluorine is as follows:

  $\text{Number}\text{of}\text{group}=\left(12+\text{Number}\text{of}\text{electrons}\text{in}\text{last}\text{p}\text{subshell of fluorine}\right)$

Number of electrons in last $\text{p}$ subshell of fluorine is 5.

Substitute the value in the above formula.

  $\begin{array}{c}\text{Number}\text{of}\text{group}=\left(12+\text{Number}\text{of}\text{electrons}\text{in}\text{last}\text{p}\text{subshell of fluorine}\right)\\ =12+5\\ =17\end{array}$

(c)

Interpretation Introduction

Interpretation: Name of the parent atom, its mass number and its group and period numbers of bellow mentioned ionic depiction should be given.

  

Concept introduction:Total number of protons in an element is known as its atomic number and it is represented with symbol $\left(\text{Z}\right)$ . Also in any atom has equal number of protons and electrons to maintain its electrical neutrality. Mass number $\left(\text{A}\right)$ of any isotope of an element is determined by the addition of its atomic number $\left(\text{Z}\right)$ with its neutron number $\left(\text{N}\right)$ .

Formula to calculate the mass number $\left(\text{A}\right)$ from neutron number $\left(\text{N}\right)$ , and its atomic number $\left(\text{Z}\right)$ is as follows:

  $\text{Mass number}\left(\text{A}\right)=\text{Neutron number}\left(\text{N}\right)+\text{Atomic number}\left(\text{Z}\right)$

To calculate the group number of the atom, we have to consider its electronic configuration.

Formula to calculate the period number of an atom is as follows:

  $\text{period}\text{number}=\left(\begin{array}{l}\text{principle}\text{quantum}\\ \text{number}\text{of}\text{valence shell}\end{array}\right)$

Formula to calculate the group number of s-block elements are as follows:

  $\text{Number}\text{of}\text{group}=\text{Number}\text{of}\text{electrons}\text{in}\text{last}\text{s}\text{subshell}$

Formula to calculate the group number of p-block elements are as follows:

  $\text{Number}\text{of}\text{group}=\left(12+\text{Number}\text{of}\text{electrons}\text{in}\text{last}\text{p}\text{subshell}\right)$

Formula to calculate the group number of d-block elements are as follows:

  $\text{Number}\text{of}\text{group}=\left(2+\text{Number}\text{of}\text{electrons}\text{in}\text{last}\text{d}\text{subshell}\right)$

Inert gases are placed in group number 18 in the modern periodic table.

Explanation of Solution

Number of protons in the ionic depiction is 20. Hence its atomic number is 20. So the parent atom is calcium $\left(\text{Ca}\right)$ .

Formula to calculate the mass number $\left(\text{A}\right)$ of calcium from neutron number $\left(\text{N}\right)$ of calcium, and its atomic number $\left(\text{Z}\right)$ is as follows:

  $\text{Mass number}\left(\text{A}\right)\text{of}\text{calcium}=\left(\begin{array}{l}\text{Neutron number}\left(\text{N}\right)\text{of}\text{calcium}+\\ \text{Atomic number}\left(\text{Z}\right)\text{of}\text{calcium}\end{array}\right)$

Atomic number of calcium is 20.

Neutron number of calcium is 20.

Substitute the values in the above formula.

  $\begin{array}{c}\text{Mass number}\left(\text{A}\right)\text{of}\text{calcium}=\left(\begin{array}{l}\text{Neutron number}\left(\text{N}\right)\text{of}\text{calcium}+\\ \text{Atomic number}\left(\text{Z}\right)\text{of}\text{calcium}\end{array}\right)\\ =20+20\\ =40\end{array}$

Number electrons present in the parent atom of the atomic depiction is equal to its atomic numbe, that is equal to 20. Hence electronic configuration will be $1{\text{s}}^{2}2{\text{s}}^{2}2{\text{p}}^{6}3{\text{s}}^2{\text{3p}}^6{\text{4s}}^2$ . As last electron of calcium is in $4\text{s}$ subshell so oxygen is $\text{s}$ block element.

Formula to calculate the period number of calcium is as follows:

  $\text{Period}\text{number of calcium}=\left(\begin{array}{l}\text{principle}\text{quantum}\text{number}\\ \text{of}\text{valence shell of calcium}\end{array}\right)$

Principle quantum number of valance shell of calcium is 4.

Substitute the values in the above formula.

  $\begin{array}{c}\text{Period}\text{number of calcium}=\left(\begin{array}{l}\text{principle}\text{quantum}\text{number}\\ \text{of}\text{valence shell of calcium}\end{array}\right)\\ =4\end{array}$

Formula to calculate the group number of s-block element, calcium is as follows:

  $\text{Number}\text{of}\text{group}=\text{Number}\text{of}\text{electrons}\text{in}\text{last}\text{s}\text{subshell of calcium}$

Number of electrons in last $\text{s}$ subshell of calcium is 2.

Substitute the value in the above formula.

  $\begin{array}{c}\text{Number}\text{of}\text{group}=\text{Number}\text{of}\text{electrons}\text{in}\text{last}\text{s}\text{subshell of calcium}\\ \text{=2}\end{array}$