Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
Solving Problems: A Chemistry Handbook
Chemistry: Matter and Change
69
SOLVING PROBLEMS:
A CHEMISTRY HANDBOOK
CHAPTER
7
Practice Problems
Name the ionic compounds that have the following formulas.
20. NH 4 I
21. NaBrO 3
22. Mg(NO 3 ) 2
23. KHSO 4
24. NH 4 ClO 4
25. Al(ClO) 3
26. FeF 2
7.4 Metallic Bonds and Properties of Metals
The bonding in metals is explained by the electron sea model,
which proposes that the atoms in a metallic solid contribute their
valence electrons to form a “sea” of electrons that surrounds metallic cations. These delocalized electrons are not held by any specific
atom and can move easily throughout the solid. A metallic bond is
the attraction between these electrons and a metallic cation.
Many of the properties of metals can be explained by means of
metallic bonds and delocalized electrons. For example, metals generally have extremely high boiling points because it is difficult to
pull metal atoms completely away from the group of cations and
attracting electrons. The melting points are considerably lower
because of the mobility of the cations and electrons, which can
move past each other. Metals are also malleable (able to be hammered into sheets) and ductile (able to be drawn into wire) because
of the mobility of the particles. The delocalized electrons make metals good conductors of electricity. These electrons also interact with
light, which is why metals tend to be highly lustrous.
A mixture of elements that has metallic properties is called an
alloy. Alloys can be of two basic types. A substitutional alloy is one
in which atoms of the original metal are replaced by other atoms of
similar size. An interstitial alloy is one in which the small holes in a
metallic crystal are filled by other smaller atoms.
Solving Problems: A Chemistry Handbook
Chemistry: Matter and Change
69
SOLVING PROBLEMS:
A CHEMISTRY HANDBOOK
CHAPTER
7
Practice Problems
Name the ionic compounds that have the following formulas.
20. NH 4 I
21. NaBrO 3
22. Mg(NO 3 ) 2
23. KHSO 4
24. NH 4 ClO 4
25. Al(ClO) 3
26. FeF 2
7.4 Metallic Bonds and Properties of Metals
The bonding in metals is explained by the electron sea model,
which proposes that the atoms in a metallic solid contribute their
valence electrons to form a “sea” of electrons that surrounds metallic cations. These delocalized electrons are not held by any specific
atom and can move easily throughout the solid. A metallic bond is
the attraction between these electrons and a metallic cation.
Many of the properties of metals can be explained by means of
metallic bonds and delocalized electrons. For example, metals generally have extremely high boiling points because it is difficult to
pull metal atoms completely away from the group of cations and
attracting electrons. The melting points are considerably lower
because of the mobility of the cations and electrons, which can
move past each other. Metals are also malleable (able to be hammered into sheets) and ductile (able to be drawn into wire) because
of the mobility of the particles. The delocalized electrons make metals good conductors of electricity. These electrons also interact with
light, which is why metals tend to be highly lustrous.
A mixture of elements that has metallic properties is called an
alloy. Alloys can be of two basic types. A substitutional alloy is one
in which atoms of the original metal are replaced by other atoms of
similar size. An interstitial alloy is one in which the small holes in a
metallic crystal are filled by other smaller atoms.