example 10-3 Writing Simple Lewis Structures
Write a Lewis structure for the ammonia molecule, NH3
Analyze
To write a Lewis structure we must know the number of valence electrons associated with each atom.
Solve
The valence electrons can then be represented in the Lewis symbols, as shown here.
Now we can assemble one N and three H atoms into a structure that gives the N atom a valence-shell octet and each of the H atoms two valence electrons (producing the electron configuration of He).
Assess
The application of the octet rule has led us to the correct Lewis structure for ammonia, but, as we will see later in this text, many molecules do not obey the octet rule.
Practice example A: Write Lewis structures for Br2, CH4, and HOCl.
Practice example B: Write Lewis structures for NI3, N2H4, and C2H6.