Chapter 5, Problem 42A

a)

Interpretation Introduction

Interpretation: The number of electrons in the highest occupied energy of the atoms is to be identified.

Concept Introduction: Electronic configurations refer to the arrangements of electrons in different orbitals around atoms' nuclei.

Answer to Problem 42A

The number of electrons in the highest occupied energy level of barium atom is $2$ .

Explanation of Solution

Electronic configurations refer to the arrangements of electrons in different orbitals around atoms' nuclei.

The Aufbau principle, the Pauli exclusion principle, and Hund's rule are three rules that can be used to determine the electronic configuration of atoms.

To find the electrons in the highest energy level, the electronic configuration should be known.

The atomic number of barium is 56.

The electronic configuration of the barium atom is written as follows:

  $1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}3d^{10}4s^{2}4p^{6}4d^{10}5s^{2}5p^{6}6s^2$

The highest occupied energy level in barium is the 6^th orbital and the number of electrons is $2$ .

b)

Interpretation Introduction

Interpretation: The number of electrons in the highest occupied energy of the atoms are to be identified.

Concept Introduction: Electronic configurations refer to the arrangements of electrons in different orbitals around atoms' nuclei.

Answer to Problem 42A

The number of electrons in the highest occupied energy level of an aluminum atom is $3$ .

Explanation of Solution

Electronic configurations refer to the arrangements of electrons in different orbitals around atoms' nuclei.

The Aufbau principle, the Pauli exclusion principle, and Hund's rule are three rules that can be used to determine the electronic configuration of atoms.

To find the electrons in the highest energy level, the electronic configuration should be known.

The atomic number of aluminum is 13.

The electronic configuration of the aluminum atom is written as follows:

  $1s^{2}2s^{2}2p^{6}3s^{2}3p^1$

The highest occupied energy level in aluminum is 3^rd orbital and the number of electrons is $3$ .

c)

Interpretation Introduction

Interpretation: The number of electrons in the highest occupied energy of the atoms is to be identified.

Concept Introduction: Electronic configurations refer to the arrangements of electrons in different orbitals around atoms' nuclei.

Answer to Problem 42A

The number of electrons in the highest occupied energy level of sodium atom is $1$ .

Explanation of Solution

Electronic configurations refer to the arrangements of electrons in different orbitals around atoms' nuclei.

The Aufbau principle, the Pauli exclusion principle, and Hund's rule are three rules that can be used to determine the electronic configuration of atoms.

To find the electrons in the highest energy level, the electronic configuration should be known.

The atomic number of sodium is 11.

The electronic configuration of the sodium atom is written as follows:

  $1s^{2}2s^{2}2p^{6}3s^1$

The highest occupied energy level in sodium is 3^rd orbital and the number of electrons is $1$ .

d)

Interpretation Introduction

Interpretation: The number of electrons in the highest occupied energy of the atoms is to be identified.

Concept Introduction: Electronic configurations refer to the arrangements of electrons in different orbitals around atoms' nuclei.

Answer to Problem 42A

The number of electrons in the highest occupied energy level of oxygen atom is $6$ .

Explanation of Solution

Electronic configurations refer to the arrangements of electrons in different orbitals around atoms' nuclei.

The Aufbau principle, the Pauli exclusion principle, and Hund's rule are three rules that can be used to determine the electronic configuration of atoms.

To find the electrons in the highest energy level, the electronic configuration should be known.

The atomic number of oxygen is 6.

The electronic configuration of the oxygen atom is written as follows:

  $1s^{2}2s^{2}2p^4$

The highest occupied energy level in oxygen is 2^nd orbital and the number of electrons is $6$ .