Chapter 9, Problem 9.2QE

(a)

Interpretation Introduction

Interpretation:

The Lewis electron-dot symbols that show the formation of barium bromide from the atoms has to be determined.

Concept Introduction:

Lewis electron-dot symbols can be used to predict the number of bonds formed by most elements in their compounds. Lewis electron-dot symbol consists of the chemical symbol for an element surrounded by dots that represent its valence electrons.

Some features of the Lewis electron-dot symbol are as follows:

1. It is the representation of valence electrons.

2. It allows to keep track of valence electrons during bond formation.

3. It consists of the chemical symbol for the element and a dot for each valence electron.

The steps to write Lewis electron-dot symbol are as follows:

Step1: In this step, the dots that represent its valence electrons are placed one at a time, around the element’s chemical symbol. The first four dots are placed above, below, to the left, and to the right of the symbol. So, those elements with four or fewer valence electrons have one dot in each position.

Step 2: The dots for elements with more than four valence electrons are again placed one by one. The first four valence electrons are paired one by one.

(b)

Interpretation Introduction

Interpretation:

The Lewis electron-dot symbols that show the formation of potassium sulfide from the atoms have to be determined.

Concept Introduction:

Refer to part (a).