2. THE NATURE OF SOLIDS
Objectives:
1. Describe the difference in structure of crystalline and amorphous solids.
2. Describe the different types of crystals and their properties: ionic, covalent,
molecular, and metallic.
3. Describe the nature of the following phase changes in terms of energy change and
the increase or decrease. in molecular order: solid-liquid, liquid-vapor, and solid-vapor.
Chapter 1: Lesson 3
3. SOLIDS
Amorphous
Solids
Solids without
a crystal lattice
Ionic
solids
Crystalline
Solids
THE NATURE OF SOLIDS
How are the structures and properties of solids related?
What determines the shape of a crystal?
Metallic
solids
are either
exist as
or
Molecula
r solids
Covalent
network
solids
4. Sublimation
Activity 3. Sublimation
Objective
To observe the sublimation of air freshener
Materials
Two test tubes (big and small) hot water
Small pieces of air freshener ice
Two cardboard strips beaker
Procedure
1. Put small pieces of air freshener in the bigger test
tube.
2. Bend the cardboard strips, and place them over the
brim of the test tube that has the air freshener juices.
3. Place the smaller test tube inside the bigger test tube.
The base of the smaller test tube should not touch the
air freshener. Adjust the cardboard as necessary. This
assembly serves as the sublimation setup.
4. Fill the small test tube with crushed ice. No ice or
water should go to the bigger test tube.
5. Place your sublimation setup in the beaker with hot
water.
6. Observe what happens.
Questions for Analysis
1. What is sublimation?
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2. What would happen if the water in the beaker were at room temperature? If it were
boiling?
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3. Why is it possible to separate the substances in some mixtures by sublimation?
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5. Types and
Properties of
Solids
Solid can be classified as crystalline or
amorphous based on the arrangement
of their particles.
Crystalline solids have highly regular
arrangement of particles, while
amorphous solids have considerable
disorder in their structure.
6. AMORPHOUS SOLIDS
Amorphous solids (from Greek word for
“without form”)
- are solids whose particles do not have
orderly structures
- they have poorly-defined shapes
- they are formed rapidly that its
constituents particles do not have time to
align or organize into a more crystalline
lattice (Ex. Glass)
7. Types and
Properties of
Solids
Crystalline Solids have well-defined
crystal lattice.
A lattice is a three-dimensional
system of points designating the positions
of the components (ions, atoms, or
molecules) that make up a crystal.
10. Types and
Properties of
Solids
Three kinds of cubic unit cells:
1. simple cubic – has atom in each corners
2. centered cubic - has an additional atom at the center of its
cube
3. face-centered cubic - has additional atoms on each of its six
faces
11. TYPES COMPONENTS THAT
OCCUPY THE LATTICE
POINTS
TYPE OF INTERACTION
BETWEEN
COMPONENTS OF
LATTICE
TYPICAL PROPERTIES EXAMPLES
IONIC Ions Ionic Hard, high melting point,
insulating as solid but
conducting when dissolved
NaCl and 𝑀𝑔𝐶𝑙2
MOLECULAR Discrete molecules Dipole-dipole or
London dispersion
Soft, low melting point Ice, dry ice, 𝐶𝐻4,
𝐶12𝐻22𝑂11, 𝐶𝑂2, 𝐵𝑟2
METALLIC Metal atoms Delocalized covalent Wide range of hardness and
melting points
All metallic elements
e.g. Silver, Iron, Brass,
NETWORK Nonmetal atoms Directional covalent Hard, high melting point Diamond
GROUP 8A Noble gases London dispersion
forces
Very low melting point Argon
Types of Crystalline
Solids
