Guided Notes Chapter 6: Covalent Compounds
Section 1: Covalent Bonds
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Explain the role and location of electrons in a covalent bond.
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Describe the change in energy and stability that takes place as a covalent bond forms.
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Distinguish between nonpolar and polar covalent bonds based on electronegativity differences.
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Compare the physical properties of substances that have different bond types, and relate bond
types to electronegativity differences.
A ____________ bond is a bond formed when atoms share one or more pairs of electrons. The
shared electrons move within a space called a molecular orbital. A ______________ orbital is the region
of high probability that is occupied by an individual electron as it travels with a wavelike motion in the
three-dimensional space around one of two or more associated nuclei.
The __________ length is the distance between two bonded atoms at their minimum potential
energy. However, the two nuclei in a covalent bond ___________ back and forth. The bond length is
thus the _____________ distance between the two nuclei. The energy required to break a bond
between two atoms is the bond _____________. Bonds that have the higher bond energies (stronger
bonds) have the ___________ bond lengths
A covalent bond in which the bonding electrons in the molecular orbital are shared equally is a
________________ covalent bond. A covalent bond in which the bonding electrons in the molecular
orbital are shared unequally is a ____________ covalent bond. A molecule in which one end has a
partial positive charge and the other end has a partial negative charge is called a ___________. In a
polar covalent bond, the shared pair of electrons is not transferred completely. Instead, it is more likely
to be found near the __________ electronegative atom.
The symbol  is used to mean partial.
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+ is used to show a partial positive charge
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– is used to show a partial negative charge charge
A covalent bond forms between two _________. An _________ bond forms between a nonmetal and a
metal. The type of bond that forms (metallic, ionic, or covalent) determines the properties of the
substance.
Review Questions:
1. Describe the attractive and repulsive forces that exist between two atoms as the atoms move
closer together.
2. Why does the distance between two nuclei in a covalent bond vary?
3. How does the strength of a covalent bond relate to bond length?
Chapter 6, Section 2: Drawing and Naming Molecules
Objectives:
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Draw Lewis structures to show the arrangement of valence electrons among atoms in molecules
and polyatomic ions.
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Explain the differences between single, double, and triple covalent bonds.
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Draw resonance structures for simple molecules and polyatomic ions, and recognize when they
are required.
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Name binary inorganic covalent compounds by using prefixes, roots, and suffixes.
__________ electrons are the electrons in the outermost energy level of an atom. A _________
structure is a structural formula in which valence electrons are represented by dots. In Lewis structures,
dot pairs or dashes between two atomic symbols represent ________ in covalent bonds. An element
with an octet of valence electrons has a _______ configuration. The tendency of bonded atoms to have
octets of valence electrons is called the ______ rule. An unshared pair, or a lone pair, is a nonbonding
pair of electrons in the valence shell of an atom. A _______ bond is a covalent bond in which two atoms
share one pair of electrons. A ________ bond is a covalent bond in which two atoms share two pairs of
electrons. A _________ bond is a covalent bond in which two atoms share three pairs of electrons.
Single Bond
Double Bond
Triple Bond
Naming Covalent Compounds:
The first element named is usually the first one written in the formula. It is usually the lesselectronegative element. The second element named has the ending -ide. Unlike the names for ionic
compounds, the names for covalent compounds must often distinguish between two different
molecules made of the same elements.
Review Questions:
1. Which electrons are shown in a Lewis structure?
2. How do the names for SO2 and SO3 differ?
3. Draw Lewis Structures for the following compounds:
a. BrF
b. NH3
c. Cl2O
d. ClO24. Write the formula for the following compounds:
a. Phosphorus pentabromide
b. Diphosphorus trioxide
c. Arsenic trichloride
d. Carbon tetrachloride
Chapter 6, Section 3: Molecular Shapes
Objectives:
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Predict the shape of a molecule using VSEPR theory.
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Associate the polarity of molecules with the shapes of molecules, and relate the polarity and
shape of molecules to the properties of a substance.
The v______ s______ e__________ p______ r___________ (VSEPR) theory is a theory that predicts
some molecular shapes based on the idea that pairs of valence electrons surrounding an atom repel
each other. According to the VSEPR theory, the shape of a molecule is determined by the ___________
electrons surrounding the central atom. Electron pairs are negative, so they _______ each other.
Therefore, the shared pairs that form different bonds repel each other and remain as far apart as
possible.
One property that shape determines is the _________ of a molecule. The polarity of a molecule that
has more than two atoms depends on the polarity of each bond and the way the bonds are arranged in
space. If two dipoles are arranged in opposite directions, they will __________ each other. If two dipoles
are arranged at an angle, they will ________ cancel each other. Compare the molecules of nonpolar
carbon dioxide, CO2, which has a linear shape, and polar water, H2O, which has a bent shape.
Review Questions:
1. In VSEPR theory, what information about a central atom do you need in order to predict the
shape of a molecule?
2. Explain how a Lewis structure can help to predict the shape of a molecule.
3. Use VSEPR theory to determine the shapes of the following molecules:
a. SCl2
b. PF3
c. NH3