Chapter 8, Problem 8.61QP

(a)

Interpretation Introduction

Interpretation: The atoms $Li$, $Na$ and $K$ has to be arranged in order of increasing positive electron affinity.

Concept Introduction:

Electron Affinity: It is energy change taking place when one electron is added to an atom which is neutral in its gaseous state forming an anion.

Along the period, electron affinity increases from left to right expect for Group 2A, Group 8A and Group 5A.

In the case of Group 2A and Group 8A elements, the subshells are completed so the electron has to be added to a subshell with higher energy.

In the case of Group 5A elements, the p subshell is half–fill hence has high electron–electron repulsion.

Down the group, the electron affinity values vary a little.

(b)

Interpretation Introduction

Interpretation: The atoms $F$, $Cl$, $Br$ and $I$ has to be arranged in order of increasing positive electron affinity.

Concept Introduction:

Electron Affinity: It is energy change taking place when one electron is added to an atom which is neutral in its gaseous state forming an anion.

Along the period, electron affinity increases from left to right expect for Group 2A, Group 8A and Group 5A.

In the case of Group 2A and Group 8A elements, the subshells are complete so the electron has to be added to a subshell with higher energy.

In the case of Group 5A elements, the p subshell is half–fill hence has high electron–electron repulsion.

Down the group, the electron affinity values vary a little.

(c)

Interpretation Introduction

Interpretation: The atoms $O$,$Si$, $P$, $Ca$ and $Ba$ has to be arranged in order of increasing positive electron affinity.

Concept Introduction:

Electron Affinity: It is energy change taking place when one electron is added to an atom which is neutral in its gaseous state forming an anion.

Along the period, electron affinity increases from left to right expect for Group 2A, Group 8A and Group 5A.

In the case of Group 2A and Group 8A elements, the subshells are complete so the electron has to be added to a subshell with higher energy.

In the case of Group 5A elements, the p subshell is half-fill hence has high electron–electron repulsion.

Down the group, the electron affinity values vary a little.