KEY
Name
Date
Class _ _ _ __
7-2 Review and Reinforcement
.('
Covalent Bonding
If the statement is true, write "true." If it is false, change the underlined word or words to make it
I.
true. Write your answer on the line provided.
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I
covelent
1. A group of atoms united by ionic bonds is called a molecule.
!
true
2. A covalent bond is formed by a of electrons.
four
3. A double covalent bond consists of two shared electrons.
true
4. A :molecular formula tells you how many atoms are in a single
molecule of the compound.
structural
5. The empirical formula for a molecule specifies which atoms are
bonded to each other in the molecule:
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I
I
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unshared/lone pair
6. A pair of electrons not involved in bonding is called a shared
electron pair.
·
equally
7. In nonpolar covalent bonds, the electrons are shared unequally
between two atoms.
triple
8. Lewis structures use a triple dash to represent a· double bond.
' (-#
Use the .information in ·Figure 7-19 of the textbook to calculate the electronegativity differences
between each pair of elements listed in the chart below. Then indicate whether the bond would be
nonpolar covalent, polar covalent, or ionic. Write your answers in the chart.
·
Electronegativity Difference
H-0
9.
C-H
10•.
11.
12.
13.
K-F
..
.
Type of Bond
1.4
polar covalent
0.4
nonpolar covalent
3.2
ionic
0.9
polar covalent
3.1
ionic
0.5
polar covalent
N-H
Na-F
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I •
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.14.
0-CI
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14 Chapter 7 .
© Prentice-Hall, Inc.
Name ___________________________ Date ___________ Class _______
7-2 Review and Reinforcement (continued)
Write Lewis structures for each of the following molecules. Indicate the bonds with either dots
·
ordashes.
15. NH3
1s. Pel;
19. CC14
Answer the following questions as directed.
21. Explain why the molecule SF4 is an exception to the octet rule:
10e- surround the Sulphur atom, not 8. Holds additional e- in empty 3d orbitals.
22. Explain the relationship between electronegativity and polarity.
The greater the electronegativity difference, the more polar the bond.
· 23. Compare and contrast single, double, and triple covalent bonds.
All three are covalent bonds. Single = one shared e- pair, double = two shared
e- pairs, triple = three shared electron pairs.
© Prentice-Hall, Inc.
Chapter 7 15