Download Unit 6 Worksheet Package

Dr. Corell - Chemistry I
Study Guideline: Unit 6
Chemical Bonding
________________________________________________________________________________________________________________________
1. Distinguish between covalent, polar covalent and ionic bonding using
electronegativity differences of bonding atoms.
2. Explain the properties of metals based on metallic bonding.
3. Write electron dot structures for representative atoms.
4. Draw electron dot structures for polyatomic ions.
5. Write electron dot structures for simple molecules.
6. Apply the octet rule to describe molecular structures.
7. List exceptions to the octet rule.
8. Define bond energies and explain how they can be used to compare bond
strengths of different chemical bonds.
9. Describe polarity in bonds and how that can create hydrogen bonding.
10. Explain how a molecule made of polar bonds can be nonpolar.
Ionic and Covalent Bonding
Word Bank
anion
electrons
noble gas
cation
ions
octet
electron configuration
negative
positive
1. An ionic bond is an attraction between oppositely charged __________________.
2. Anions have a _________________ charge.
3. An atom becomes an ion by losing or gaining _____________________.
4. The _______________ rule states that atoms tend to gain, lose or share electrons in order to acquire a
full set of valence electrons.
5. When sodium and chlorine form an ionic bond, both ions acquire the electron configuration of a(n)
__________ _______.
True/False - Write true if the statement is true. If the statement is false change the
underlined word to make the statement true.
_________________ 6. Calcium becomes a monoatomic cation by gaining two electrons.
_________________ 7. A cation has a positive charge.
_________________ 8. A covalent bond is formed by a shared pair of electrons.
_________________ 9. The Lewis dot diagram for chlorine has six electrons.
_________________ 10. A group of atoms united by ionic bonds is called a molecule.
11. Define electronegativity
12. How does electronegativity vary as the atomic number of an element increases within a period.
Explain.
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Draw the Lewis dot diagrams for the following elements and compounds:
16. Boron
17. Chlorine
18. Oxygen
19. Neon
20. Silicon
21. Sodium
22. Aluminum
23. Magnesium
24. H2
25. ClF
26. NH3
27. Cl2O
28. PCl3
29. CI4
30. CCl4
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31. C2Cl6
32. CO2
33. C2Cl4
34. C2Cl2
35. NF4+
36. SO42–
37. Explain why the molecule SF4 is an exception to the octet rule.
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Electronegativity and Bond Polarity
The ability of an atom to attract a shared pair of electrons in a chemical bond is called electronegativity.
Fill in the graphs and answer the following questions by referring to the electronegativities on your red,
white and blue periodic table.
1. Using the grid below, graph electronegativity versus atomic number for the halogens.
4.0
2. How does electronegativity
vary with atomic number in
the halogens? Explain why
this trend is seen.
3.0
Electronegativity
2.0
1.0
10
20
30 40 50 60
Atomic Number
70
80
90
3. Using the grid below, graph electronegativty versus atomic number for the elements in period #2.
4.0
4. How does electronegativity vary
with atomic number for the elements
in period #2? Explain why this trend
3.0
is seen.
Electronegativity
2.0
1.0
3
4
5
6
7
8
Atomic Number
9
5. Why is no value for electronegativity shown for element 10 in the table in your book?
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6. Referring to a table of electronegativities in your book, arrange the following compounds in order of
increasing ionic character: LiF, LiBr, KCl, KI.
7. What is the difference between an ionic and a covalent bond?
8. Explain how electronegativity and bond polarity are related.
True/False - Write true if the statement is true. If the statement is false change the underlined word to
make the statement true.
_________________ 9. A double bond consists of two pairs of shared electrons.
_________________ 10. A pair of electrons not involved in bonding is called a shared electron pair.
_________________ 11. In non-polar covalent bonds the electrons are shared unequally between two
atoms.
_________________ 12. Lewis structures use a quadruple dash to indicate the four electron involved
in a double bond.
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Polarity of Bonds
Bond
Electronegativity Difference
Type of Bond
H–O
C–H
K–F
N–H
Na–S
Na–F
O–Cl
Mg–O
Br–Br
Li–H
Cu–F
C–O
H–At
Al–O
Al–S
Bi–Cl
P–O
C-Cl
Ti–Br
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Atom with greater electron share
Bonding Review
Atoms are held together in ______________ by chemical bonds. Chemical bonds result from
the sharing or transfer of ____________ between pairs of atoms. Bonded atoms attain the stable
electron configuration of a __________ ______. The transfer of valence electrons produces positively
charged ions, or _____________, and negatively charged ions called _____________. The attraction
between these two types of ions forms an _____________ bond.
Nearly all ionic compounds are _____________ solids at room temperature. In these solids the
total _____________ charge is balanced by the total _____________ charge. Ionic compounds in
general have very _____________ melting points. This is because of the _____________ attractive
forces between ions results in a very _____________ structure. Ionic compounds conduct electricity
when _____________ in water or when in the _____________ state.
Metals consist of metal ions packed together and surrounded by a sea of mobile _____________.
This arrangement is called a(n) ____________ bond. The electron mobility accounts for the excellent
_____________ conductivity of metals and helps explain why metals are both _____________ and
_____________. Metal atoms are commonly packed into three different arrangements. They are called
______-_____________, ______-_____________, and ________ _____________.
When atoms share electrons to gain the _____________ configuration of a noble gas, the bonds
that are formed are called _____________. A single _____________ pair of valence electrons
constitutes a ___________ covalent bond. Sometimes two or three pairs of electrons may be shared to
form ___________ or ____________ covalent bonds. In some cases only one of the atoms in a bond
provides the pair of bonding electrons; this is called a(n) _______________ _____________ _______.
When like atoms are joined by a covalent bond, the bonding electrons are shared ____________,
and the bond is a(n) _____-__________ covalent bond. The degree of polarity of a bond between any
two atoms is determined by consulting a table of ___________________. Some molecules are
_____________ because they contain polar covalent bonds. The attraction between opposite poles of
polar molecules constitutes a __________-_____________ interaction. The dipole-dipole interaction is
one of several _____________ attractions between molecules. Another weak attractive forces is the
____________-_____. The strength of these weak attractive forces determines whether a covalent
compound will be a _____________, _____________ or a gas at room temperature.
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