Chapter 16: Covalent
Compounds
Ms. Knick
HAHS
What is a Covalent Compound?
• A covalent compound is a chemical bond
formed between a 2 or more nonmetals.
Stability
• Nonmetals join with one another to obtain 8
electrons (octet).
• An atom with 8 electrons is considered to be
stable.
• However, there are exceptions to the octet
rule.
– H: is stable with 2 electrons
– B: is stable with 6 electrons
– S: is stable with 12 electrons
Electrons
• Remember that in an ionic bond, electrons are
transferred or donated.
• However, in a covalent bond, electrons are
shared among both atoms in the bond.
Why Bond?
Potential Energy is
minimized. Atoms in
the bond are stable.
Lewis Structures
• Diagrams that show the bonding between
atoms of a molecule and the lone pairs of
electrons that may exist in the molecule.
• A Lewis structure can be drawn for any
covalently bonded molecule
Examples:
Writing Lewis Structures for Charged
Molecules
• Negative: Gained electrons; add to the
number of your total valence electrons
• Positive: Lost electrons; subtract from the
number of your total valence electrons
Molecular Geometry
Molecular Geometry and VSEPR
(Valence Shell Electron Pair Repulsion
• Molecular Geometry is the 3-D
arrangement of the atoms that
constitute a molecule.
• VSPER is used to predict the
geometry based upon the extent of
electron-pair repulsion.
Number of Lone
Pairs Around the
Central Atom
Shape of Molecule
0
Linear
2
1
Bent
2
2
Bent
3
0
Trigonal Planar
3
1
Trigonal Pyramidal
4
0
Tetrahedral
5
0
Trigonal Bypyramidal
6
0
Octahedral
2
Number of Bonds
attached to the
central atom
Molecular Geometry Lab Guidelines
• All students must complete the handout and turn
it in before the end of class.
• This assignment will be graded, so do your best! 
• When working with the kits:
– Part I and II: Follow the color coding for atoms in the
box; your drawings of the compounds should reflect
the color coding. LONE PAIRS WILL BE REPRESENTED
WITH A WOODEN STICK ATTACHMENT!
– Part II: Be sure all drilled holes are filled for each
model that you create! 
Length of Bonds
• Triple bonds are the shortest in length; single
bonds are the longest in length.
• Triple bonds require more of an orbital
overlap in order to join the electrons in a bond
making them the shortest in length.
Breaking Bonds
• Triple bonds require the most amount of
energy to break the bond between atoms.
• Single bonds require the least amount of
energy to break bond between atoms.
Two types of Covalent Bonds
• 1. Nonpolar Covalent : The bonding electrons are
shared equally. The differences in electronegativity
are 0- 0.3
• 2. Polar Covalent : The bonding electrons are shared
unequally. (ONE ATOM IS NOT PLAYING NICE! ) The
differences in electronegativity are greater than 0.3
Nonpolar vs. Polar
Non-Polar
Chlorine is not playing
nice! 
Electronegativity Chart
• Classify the following as polar covalent or
nonpolar covalent:
H—Cl
C—F
N—O
Xe—F
O—O
S—F
Covalent Compound Poster Project
• Select and Research a commonly used covalent
compound.
• Draw the Lewis Structure (10 points).
• Explain the uses/property/characteristics (20
points).
• Label at least one polar bond and at least one
nonpolar covalent bond (10 points).
• Make the presentation creative; Give it a creative
title! (10 points)
• Can not use Ms. K’s example!
Need a kick start to your morning?
Nonpolar
Polar bond
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nervous system stimulant, temporarily warding off drowsiness and restoring
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unlike many other psychoactive substances, it is legal and unregulated in
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Writing Assignment
• The journal entry must be a minimum of 1 page
(front).
• You should include: A summary of what you
learned about covalent compounds (electrons,
Lewis dot structures, molecular geometry, polar
covalent, nonpolar covalent)
• You should include: An application to real world
(THINK OF YOUR POSTER PROJECT).
• Refer to rubric for grading!