Chapter 5, Problem 58A

Interpretation Introduction

Interpretation: The number of paired electrons in an atom of each element is to be determined.

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

Answer to Problem 58A

There are two paired electrons in the helium element.

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.

The energy levels and symbols for each sub-level occupied by an electron are written for an atom's electrical configuration.

The given element is helium.

The electronic configuration of helium is $1s^2$ .

There is only one orbital that can accommodate only two electrons. So, the atoms are filled.

Hence, there are two paired electrons in helium.

Interpretation Introduction

Interpretation: The number of paired electrons in an atom of each element is to be determined.

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

Answer to Problem 58A

There are ten paired electrons in the sodium element.

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.

The energy levels and symbols for each sub-level occupied by an electron are written for an atom's electrical configuration.

The given element is helium.

The electronic configuration of sodium is $1s^{2}2s^{2}2p^{6}3s^1$ .

There are 3 s orbitals and 1 p orbital. There are paired electrons in 1s, 2s, and 2p orbitals.

The pairing of sodium atoms is given as:

  $\begin{array}{l}1s^{2}2s^{2}2p^{6}3s^1\\ \boxed{\uparrow \downarrow }\boxed{\uparrow \downarrow }\boxed{\uparrow \downarrow }\boxed{\uparrow \downarrow }\boxed{\uparrow \downarrow }\boxed{\uparrow }\end{array}$

Hence, there are ten paired electrons in helium.

Interpretation Introduction

Interpretation: The number of paired electrons in an atom of each element is to be determined.

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

Answer to Problem 58A

There are four paired electrons in the boron element.

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.

The energy levels and symbols for each sub-level occupied by an electron are written for an atom's electrical configuration.

The given element is boron.

The electronic configuration of boron is $1s^{2}2s^{2}2p^1$ .

There are 2 s orbitals and 1 p orbital. There are paired electrons in 1s and 2s orbitals.

The pairing of boron atom is given as

  $\begin{array}{l}1s^{2}2s^{2}2p^1\\ \boxed{\uparrow \downarrow }\boxed{\uparrow \downarrow }\boxed{\uparrow }\boxed{}\boxed{}\end{array}$

Hence, there are four paired electrons in boron.

Interpretation Introduction

Interpretation: The number of paired electrons in an atom of each element is to be determined.

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

Answer to Problem 58A

There are six paired electrons in the oxygen element.

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.

The energy levels and symbols for each sub-level occupied by an electron are written for an atom's electrical configuration.

The given element is oxygen.

The electronic configuration of oxygen is $1s^{2}2s^{2}2p^4$ .

There are 2 s orbitals and 1 p orbital. There are paired electrons in 1s, 2s, and 2p orbitals.

The pairing of oxygen atoms is given as

  $\begin{array}{l}1s^{2}2s^{2}2p^4\\ \boxed{\uparrow \downarrow }\boxed{\uparrow \downarrow }\boxed{\uparrow \downarrow }\boxed{\uparrow }\boxed{\uparrow }\end{array}$

Hence, there are six paired electrons in oxygen.