Vanden Bout/LaBrake/Crawford
CH301
WHY IS EVERYTHING SO DIFFERENT?
Gas, Liquid or Solid?
UNIT 3 Day 11
What are we going to learn today?
Properties of Solids – Different Types
Physical Properties
Properties of Liquids
based on intermolecular forces and
shapes of molecules
Properties of Solids
based on intermolecular forces and the
type of bonding
iclicker polling question
Diamonds are
a) A bunch of C atoms held together by dispersion forces
b) A bunch of C molecules held together by dipole dipole
interactions
c) A bunch of C atoms covalently bound together
d) A bunch of C molecules held together by dispersion
forces
iclicker polling question
Graphite is
a) A bunch of C atoms held together by dispersion forces
b) A bunch of C molecules held together by dipole dipole
interactions
c) A bunch of C atoms covalently bound together
d) A bunch of C molecules held together by dispersion
forces
iclicker polling question
Solids are classified into four different categories
Ionic
Covalent
Metallic
Molecular
We’ve already discussed two types of solids this semester.
Which ones have we discussed?
A. Ionic and Covalent
B. Metallic and Covalent
C. Molecular and Ionic
D. Metallic and Molecular
Types of Solids
Ionic
Covalent or (Network)
Metallic
Molecular
Types of Solids
Class
Examples
Characteristics
Ionic
NaCl, KNO3,
CuSO4•H2O
Hard, rigid, brittle; high
melting/boiling points; those soluble
in water give conducting solutions
Network
B, C, black P, BN,
Hard, rigid, brittle; very high melting
SiO2
points; insoluble in water
Metallic
s- and d- elements Malleable, ductile, lustrous;
electrically and thermally conducting
Molecular BeCl2, S8, P4, I2, ice, Relatively low melting/boiling points;
glucose
brittle if pure
Physical Properties of Solids
Class
Electrons
Conductivity
Ionic
Localized
Not a good conductor (only conducts
electricity in aqueous solutions)
Network Localized
Not a good conductor
Metallic
Delocalized Good conductor
Molecular Localized
Not a good conductor
Physical Properties of Solids
Ionic
Metallic
Physical Properties of Solids
Molecular
Network
Learning Outcomes
Recognize the four types of solids: ionic, covalent (network),
metallic, and molecular
Recognize how the macroscopic properties of solids (melting
point, hardness, conductivity, etc.) can be explained by the
microscopic model of solids