Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
124 Chemistry: Matter and Change
Solving Problems: A Chemistry Handbook
SOLVING PROBLEMS:
A CHEMISTRY HANDBOOK
CHAPTER 12
dioxide in glass. Cohesion is the force of attraction between
identical molecules, such as water molecules.
Solids Strong attractive forces between the particles in a solid
limit the movement of the particles to vibrations around fixed locations. Thus, solids have a definite shape and volume.
Generally, the particles in a solid are more closely packed than
those in a liquid, making most solids more dense than most liquids.
When the solid and liquid states of a substance coexist, usually the
liquid is less dense than the solid. Liquid water and ice are an exception to this rule. Because solids are so dense, ordinary amounts of
pressure will not compress them into a smaller volume.
Crystalline solids A solid whose atoms, ions, or molecules are
arranged in an orderly, geometric, three-dimensional structure (lattice) is called a crystalline solid. The individual pieces of a
crystalline solid are called crystals. Crystalline solids are divided
into five categories based on the types of particles they contain:
atomic solids, molecular solids, covalent network solids, ionic
solids, and metallic solids. Noble gases are atomic solids whose
properties reflect the weak dispersion forces between the atoms.
Molecular solids are held together by dispersion forces, dipole–
dipole forces, or hydrogen bonds. Most molecular compounds that
are solid at room temperature, such as sugar, have a large molar
mass and are poor conductors of heat and electricity.
Elements that are able to form multiple covalent bonds, such as
carbon and silicon, are able to form covalent network solids.
The type of ions and the ratio of ions determine the structure of
the lattice and the shape of the crystal in an ionic solid. The network
of attractions gives these solids high melting points and hardness.
They are strong, but brittle, and will shatter when struck.
Metallic solids consist of positive metal ions surrounded by a
sea of mobile electrons. The mobile electrons make these solids
good conductors of heat and electricity.
Not all solids are crystalline. The particles in an amorphous
solid are not arranged in a regular, repeating pattern and do not form
crystals. Examples of amorphous solids include glass, rubber, and
many plastics.
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124 Chemistry: Matter and Change
Solving Problems: A Chemistry Handbook
SOLVING PROBLEMS:
A CHEMISTRY HANDBOOK
CHAPTER 12
dioxide in glass. Cohesion is the force of attraction between
identical molecules, such as water molecules.
Solids Strong attractive forces between the particles in a solid
limit the movement of the particles to vibrations around fixed locations. Thus, solids have a definite shape and volume.
Generally, the particles in a solid are more closely packed than
those in a liquid, making most solids more dense than most liquids.
When the solid and liquid states of a substance coexist, usually the
liquid is less dense than the solid. Liquid water and ice are an exception to this rule. Because solids are so dense, ordinary amounts of
pressure will not compress them into a smaller volume.
Crystalline solids A solid whose atoms, ions, or molecules are
arranged in an orderly, geometric, three-dimensional structure (lattice) is called a crystalline solid. The individual pieces of a
crystalline solid are called crystals. Crystalline solids are divided
into five categories based on the types of particles they contain:
atomic solids, molecular solids, covalent network solids, ionic
solids, and metallic solids. Noble gases are atomic solids whose
properties reflect the weak dispersion forces between the atoms.
Molecular solids are held together by dispersion forces, dipole–
dipole forces, or hydrogen bonds. Most molecular compounds that
are solid at room temperature, such as sugar, have a large molar
mass and are poor conductors of heat and electricity.
Elements that are able to form multiple covalent bonds, such as
carbon and silicon, are able to form covalent network solids.
The type of ions and the ratio of ions determine the structure of
the lattice and the shape of the crystal in an ionic solid. The network
of attractions gives these solids high melting points and hardness.
They are strong, but brittle, and will shatter when struck.
Metallic solids consist of positive metal ions surrounded by a
sea of mobile electrons. The mobile electrons make these solids
good conductors of heat and electricity.
Not all solids are crystalline. The particles in an amorphous
solid are not arranged in a regular, repeating pattern and do not form
crystals. Examples of amorphous solids include glass, rubber, and
many plastics.
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