Chapter 4, Problem 4.10QP

(a)

Interpretation Introduction

Interpretation: Valence electrons has to be defined and the electronic configuration for the given elements has to written to prove the number of valence electrons is equal to the group number

Concept Introduction: In the periodic table the elements are grouped based on their valence electrons. Valence electrons or outer shell electron of an atom is the total number of electrons that is present in the outer most shell of the orbital.

Electronic configuration is the distribution of electrons of atoms or molecule in the orbital. Pauli Exclusion Principle, Hund’s rule and Aufbau’s principle has to be followed to write the electronic configuration of an atom.

Pauli Exclusion Principle:

No two electrons having the same spin can occupy the same orbital. To occupy the same orbital, two electrons must have opposite spins.

Hund’s rule:

When electrons occupy orbital, one electron enters each orbital until all the orbitals contain one electron. When the orbitals are singly filled, all the electrons have same spin where as in the doubly filled orbitals, electrons have opposite spin.

Aufbau’s Principle:

Lowest energy level orbitals are filled first before occupying the higher energy level

The order in which the electrons should be filled is

1s,2s,3s,3p,4s,3d,4p,5s,4d,5p,6s,4f,5d,6p,7s,5f,6d….

Electronic configuration of Si can be represented as [Ar] $3s^{2}3p2$ implies group 4A

Hence the number of valence electrons is equal to the group number.

To define valence electrons

Explanation of Solution

Valence electron of the atom is the total number of electrons that is present in the outermost shell of the orbital. Only the valence electrons involve in bonding, results similar chemical properties of the element presented in the group. In the periodic table as we move down the group the valence electrons of the atoms are same but the orbital differ.

(b)

Interpretation Introduction

Interpretation: Valence electrons has to be defined and the electronic configuration for the given elements has to written to prove the number of valence electrons is equal to the group number

Concept Introduction: In the periodic table the elements are grouped based on their valence electrons. Valence electrons or outer shell electron of an atom is the total number of electrons that is present in the outer most shell of the orbital.

Electronic configuration is the distribution of electrons of atoms or molecule in the orbital. Pauli Exclusion Principle, Hund’s rule and Aufbau’s principle has to be followed to write the electronic configuration of an atom.

Pauli Exclusion Principle:

No two electrons having the same spin can occupy the same orbital. To occupy the same orbital, two electrons must have opposite spins.

Hund’s rule:

When electrons occupy orbital, one electron enters each orbital until all the orbitals contain one electron. When the orbitals are singly filled, all the electrons have same spin where as in the doubly filled orbitals, electrons have opposite spin.

Aufbau’s Principle:

Lowest energy level orbitals are filled first before occupying the higher energy level

The order in which the electrons should be filled is

1s,2s,3s,3p,4s,3d,4p,5s,4d,5p,6s,4f,5d,6p,7s,5f,6d….

Electronic configuration of Si can be represented as [Ar] $3s^{2}3p2$ implies group 4A

Hence the number of valence electrons is equal to the group number.

To write electronic configuration and find the group of Na

Explanation of Solution

Atomic number of Na is 10, according to Pauli exclusion principle, Hund’s rule and Aufbau’s Principle, the electronic configuration of Na represented as [Ne] $3s^1$

Na has one valence electron and it belongs to group 1A

Hence the number of valence electron is equal to the group number is proved.

(c)

Interpretation Introduction

Interpretation: Valence electrons has to be defined and the electronic configuration for the given elements has to written to prove the number of valence electrons is equal to the group number

Concept Introduction: In the periodic table the elements are grouped based on their valence electrons. Valence electrons or outer shell electron of an atom is the total number of electrons that is present in the outer most shell of the orbital.

Electronic configuration is the distribution of electrons of atoms or molecule in the orbital. Pauli Exclusion Principle, Hund’s rule and Aufbau’s principle has to be followed to write the electronic configuration of an atom.

Pauli Exclusion Principle:

No two electrons having the same spin can occupy the same orbital. To occupy the same orbital, two electrons must have opposite spins.

Hund’s rule:

When electrons occupy orbital, one electron enters each orbital until all the orbitals contain one electron. When the orbitals are singly filled, all the electrons have same spin where as in the doubly filled orbitals, electrons have opposite spin.

Aufbau’s Principle:

Lowest energy level orbitals are filled first before occupying the higher energy level

The order in which the electrons should be filled is

1s,2s,3s,3p,4s,3d,4p,5s,4d,5p,6s,4f,5d,6p,7s,5f,6d….

Electronic configuration of Si can be represented as [Ar] $3s^{2}3p2$ implies group 4A

Hence the number of valence electrons is equal to the group number.

To write electronic configuration and find the group of Ca

Explanation of Solution

Atomic number of Ca is 20, according to Pauli exclusion principle, Hund’s rule and Aufbau’s Principle, the electronic configuration of Ca represented as [Ar]4 $s^2$

Na has 2 valence electrons and it belongs to group 2A

Hence the number of valence electron is equal to the group number is proved.

(d)

Interpretation Introduction

Interpretation: Valence electrons has to be defined and the electronic configuration for the given elements has to written to prove the number of valence electrons is equal to the group number

Concept Introduction: In the periodic table the elements are grouped based on their valence electrons. Valence electrons or outer shell electron of an atom is the total number of electrons that is present in the outer most shell of the orbital.

Electronic configuration is the distribution of electrons of atoms or molecule in the orbital. Pauli Exclusion Principle, Hund’s rule and Aufbau’s principle has to be followed to write the electronic configuration of an atom.

Pauli Exclusion Principle:

No two electrons having the same spin can occupy the same orbital. To occupy the same orbital, two electrons must have opposite spins.

Hund’s rule:

When electrons occupy orbital, one electron enters each orbital until all the orbitals contain one electron. When the orbitals are singly filled, all the electrons have same spin where as in the doubly filled orbitals, electrons have opposite spin.

Aufbau’s Principle:

Lowest energy level orbitals are filled first before occupying the higher energy level

The order in which the electrons should be filled is

1s,2s,3s,3p,4s,3d,4p,5s,4d,5p,6s,4f,5d,6p,7s,5f,6d….

Electronic configuration of Si can be represented as [Ar] $3s^{2}3p2$ implies group 4A

Hence the number of valence electrons is equal to the group number.

To write electronic configuration and find the group of lithium

Explanation of Solution

Atomic number of Li is 3, according to Pauli Exclusion Principle, Hund’s rule and Aufbau’s Principle, the electronic configuration of Li represented as [He] $2s^1$

Na has 1 valence electrons and it belongs to group 1A

Hence the number of valence electron is equal to the group number is proved.

(e)

Interpretation Introduction

Interpretation: Valence electrons has to be defined and the electronic configuration for the given elements has to written to prove the number of valence electrons is equal to the group number

Concept Introduction: In the periodic table the elements are grouped based on their valence electrons. Valence electrons or outer shell electron of an atom is the total number of electrons that is present in the outer most shell of the orbital.

Electronic configuration is the distribution of electrons of atoms or molecule in the orbital. Pauli Exclusion Principle, Hund’s rule and Aufbau’s principle has to be followed to write the electronic configuration of an atom.

Pauli Exclusion Principle:

No two electrons having the same spin can occupy the same orbital. To occupy the same orbital, two electrons must have opposite spins.

Hund’s rule:

When electrons occupy orbital, one electron enters each orbital until all the orbitals contain one electron. When the orbitals are singly filled, all the electrons have same spin where as in the doubly filled orbitals, electrons have opposite spin.

Aufbau’s Principle:

Lowest energy level orbitals are filled first before occupying the higher energy level

The order in which the electrons should be filled is

1s,2s,3s,3p,4s,3d,4p,5s,4d,5p,6s,4f,5d,6p,7s,5f,6d….

Electronic configuration of Si can be represented as [Ar] $3s^{2}3p2$ implies group 4A

Hence the number of valence electrons is equal to the group number.

To write electronic configuration and find the group of iodine

Explanation of Solution

Atomic number of iodine is 53, according to Pauli exclusion principle, Hund’s rule and Aufbau’s Principle, the electronic configuration of iodine represented as  [Kr] $4d^{10}5s^{2}5p^5$

Iodine has 7 valence electrons and it belongs to group 7A

Hence the number of valence electron is equal to the group number is proved.

(f)

Interpretation Introduction

Interpretation: Valence electrons has to be defined and the electronic configuration for the given elements has to written to prove the number of valence electrons is equal to the group number

Concept Introduction: In the periodic table the elements are grouped based on their valence electrons. Valence electrons or outer shell electron of an atom is the total number of electrons that is present in the outer most shell of the orbital.

Electronic configuration is the distribution of electrons of atoms or molecule in the orbital. Pauli Exclusion Principle, Hund’s rule and Aufbau’s principle has to be followed to write the electronic configuration of an atom.

Pauli Exclusion Principle:

No two electrons having the same spin can occupy the same orbital. To occupy the same orbital, two electrons must have opposite spins.

Hund’s rule:

When electrons occupy orbital, one electron enters each orbital until all the orbitals contain one electron. When the orbitals are singly filled, all the electrons have same spin where as in the doubly filled orbitals, electrons have opposite spin.

Aufbau’s Principle:

Lowest energy level orbitals are filled first before occupying the higher energy level

The order in which the electrons should be filled is

1s,2s,3s,3p,4s,3d,4p,5s,4d,5p,6s,4f,5d,6p,7s,5f,6d….

Electronic configuration of Si can be represented as [Ar] $3s^{2}3p2$ implies group 4A

Hence the number of valence electrons is equal to the group number.

To write electronic configuration and find the group of nitrogen

Explanation of Solution

Atomic number of nitrogen is 7, according to Pauli Exclusion Principle, Hund’s rule and Aufbau’s Principle, the electronic configuration of nitrogen represented as [He] $2s^{2}2p^3$

Nitrogen has 5 valence electrons and it belongs to group 5A

Hence the number of valence electron is equal to the group number is proved.

(g)

Interpretation Introduction

Interpretation: Valence electrons has to be defined and the electronic configuration for the given elements has to written to prove the number of valence electrons is equal to the group number

Concept Introduction: In the periodic table the elements are grouped based on their valence electrons. Valence electrons or outer shell electron of an atom is the total number of electrons that is present in the outer most shell of the orbital.

Electronic configuration is the distribution of electrons of atoms or molecule in the orbital. Pauli Exclusion Principle, Hund’s rule and Aufbau’s principle has to be followed to write the electronic configuration of an atom.

Pauli Exclusion Principle:

No two electrons having the same spin can occupy the same orbital. To occupy the same orbital, two electrons must have opposite spins.

Hund’s rule:

When electrons occupy orbital, one electron enters each orbital until all the orbitals contain one electron. When the orbitals are singly filled, all the electrons have same spin where as in the doubly filled orbitals, electrons have opposite spin.

Aufbau’s Principle:

Lowest energy level orbitals are filled first before occupying the higher energy level

The order in which the electrons should be filled is

1s,2s,3s,3p,4s,3d,4p,5s,4d,5p,6s,4f,5d,6p,7s,5f,6d….

Electronic configuration of Si can be represented as [Ar] $3s^{2}3p2$ implies group 4A

Hence the number of valence electrons is equal to the group number.

To write electronic configuration and find the group of selenium

Explanation of Solution

Atomic number of selenium is 34, according to Pauli Exclusion Principle, Hund’s rule and Aufbau’s Principle, the electronic configuration of selenium represented as [Kr] $4s^{2}4p^4$

Se has 6 valence electrons and it belongs to group 6A

Hence the number of valence electron is equal to the group number is proved.

(h)

Interpretation Introduction

Interpretation: Valence electrons has to be defined and the electronic configuration for the given elements has to written to prove the number of valence electrons is equal to the group number

Concept Introduction: In the periodic table the elements are grouped based on their valence electrons. Valence electrons or outer shell electron of an atom is the total number of electrons that is present in the outer most shell of the orbital.

Electronic configuration is the distribution of electrons of atoms or molecule in the orbital. Pauli Exclusion Principle, Hund’s rule and Aufbau’s principle has to be followed to write the electronic configuration of an atom.

Pauli Exclusion Principle:

No two electrons having the same spin can occupy the same orbital. To occupy the same orbital, two electrons must have opposite spins.

Hund’s rule:

When electrons occupy orbital, one electron enters each orbital until all the orbitals contain one electron. When the orbitals are singly filled, all the electrons have same spin where as in the doubly filled orbitals, electrons have opposite spin.

Aufbau’s Principle:

Lowest energy level orbitals are filled first before occupying the higher energy level

The order in which the electrons should be filled is

1s,2s,3s,3p,4s,3d,4p,5s,4d,5p,6s,4f,5d,6p,7s,5f,6d….

Electronic configuration of Si can be represented as [Ar] $3s^{2}3p2$ implies group 4A

Hence the number of valence electrons is equal to the group number.

To write electronic configuration and find the group of Si

Explanation of Solution

Atomic number of Si is 14, according to Pauli Exclusion Principle, Hund’s rule and Aufbau’s Principle, the electronic configuration of selenium represented as [Ar] $3s^{2}3p2$ Si has 4 valence electrons and it belongs to group 4A.

Hence the number of valence electron is equal to the group number is proved.

Conclusion

Valence electrons have defined, electronic configuration of the given elements has been written and the number of valence electron is equal to the group number has been proved.

Pair 1: (a) $1s^{2}2s^{2}2p^5$ and (d) $1s^{2}2s^{2}2p^{6}3s^{2}3p^5$

Pair 2: (b) $1s^{2}2s^1$ and (e) $1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}4s^1$

Pair 3: (c) $1s^{2}2s^{2}2p^6$ and (f) $1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}4s^{2}3d^{10}4p^6$

(a)

Interpretation Introduction

To Know the reactivity of an element (a) with   ‘ $1s^{2}2s^{2}2p^5$’ electron configuration

Explanation of Solution

Since only the valence electrons involve in bonding, electrons present in the outermost shell of an atom, response for the chemical properties of an element. The given electron configuration (a) ‘ $1s^{2}2s^{2}2p^5$’of an element has 7 valence electrons, so the element present in group 7A.

(b)

Interpretation Introduction

To Know the reactivity of an element (b) with ‘ $1s^{2}2s^1$’electron configuration

Explanation of Solution

Since only the valence electrons involve in bonding, electrons present in the outermost shell of an atom, response for the chemical properties of an element. The given electron configuration (b) ‘ $1s^{2}2s^1$’of an element has 1 valence electrons, so the element present in group 1A.

(c)

Interpretation Introduction

To Know the reactivity of an element (c) with ‘ $1s^{2}2s^{2}2p^6$’electron configuration

Explanation of Solution

Since only the valence electrons involve in bonding, electrons present in the outermost shell of an atom, response for the chemical properties of an element. The given electron configuration (c) ‘ $1s^{2}2s^{2}2p^6$’of an element has 8 valence electrons and also it has the complete octet configuration. Octet rule refers the tendency of atoms to prefer eight electrons in the valence shell to form a stable configuration that leads to present the element in group 8A.

(d)

Interpretation Introduction

To Know the reactivity of an element (d) with   ‘ $1s^{2}2s^{2}2p^{6}3s^{2}3p^5$’ electron configuration

Explanation of Solution

Since only the valence electrons involve in bonding, electrons present in the outermost shell of an atom, response for the chemical properties of an element. The given electron configuration (d) ‘ $1s^{2}2s^{2}2p^{6}3s^{2}3p^5$’of an element has 7 valence electrons, so the element present in group 2A.

(e)

Interpretation Introduction

To Know the reactivity of an element (e) with ‘ $1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}4s^1$’electron configuration

Explanation of Solution

Since only the valence electrons involve in bonding, electrons present in the outermost shell of an atom, response for the chemical properties of an element. The given electron configuration (e) ‘ $1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}4s^1$’of an element has 1 valence electrons, so the element present in group 1A

(f)

Interpretation Introduction

To Know the reactivity of an element (f) with ‘ $1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}4s^{2}3d^{10}4p^6$’electron configuration

Explanation of Solution

Since only the valence electrons involve in bonding, electrons present in the outermost shell of an atom, response for the chemical properties of an element. The given electron configuration (f) ‘ $1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}4s^{2}3d^{10}4p^6$’of an element has 8 valence electrons and also it has the complete octet configuration. Octet rule refers the tendency of atoms to prefer eight electrons in the valence shell to form a stable configuration that leads to present the element in group 8A.

(g)

Interpretation Introduction

To group the properties of the elements with given electron configuration

Explanation of Solution

Elements present in the same group have similar properties, based on this the given electron configuration of the elements is paired.

Pair 1: (a) $1s^{2}2s^{2}2p^5$ and (d) $1s^{2}2s^{2}2p^{6}3s^{2}3p^5$

Pair 2: (b) $1s^{2}2s^1$ and (e) $1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}4s^1$

Pair 3: (c) $1s^{2}2s^{2}2p^6$ and (f) $1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}4s^{2}3d^{10}4p^6$