1. Kintetic Molecular Theory
The invisible motion of still objects - Ran Tivony
4:43
Phases of Matter
Kintetic Molecular Theory
States of Matter Particle animation

2. Phases of Matter Gas total disorder highly compressible low density
fills container completely
assumes shape of container
rapid diffusion
high expansion on heating
molecules are all
translating, rotating and vibrating

3. Phases of Matter Liquid disorder slightly compressible high density
does not expand to fill container
has definite volume
assumes shape of container
slow diffusion
low expansion on heating
particles are rotating and vibrating

4. Phases of Matter Crystalline Solid p396-399 ordered arrangement
slightly compressible
high density
rigidly retains its volume
has definite volume
retains its own shape
extremely slow diffusion; diffusion only at surfaces
low expansion on heating
particles are vibrating

5. Intermolecular Forces
According to the Kinetic-Molecular Theory of Matter –
the state of a substance at room temperature depends on the strength of the attraction between its particles (intermolecular forces).
Attractive Force
at Room Temp. State of Matter
strong
moderately strong
weak

6. Intermolecular Forces
According to the Kinetic-Molecular Theory of Matter –
the state of a substance at room temperature depends on the strength of the attraction between its particles (intermolecular forces).
Attractive Force
at Room Temp. State of Matter
strong solid
moderately strong liquid
weak gases

7. At different temperatures the particles/molecules have different kinetic energy.
Example: Water
Below 0°C - Water is a solid because there is not enough kinetic energy to overcome the attractive forces.
(Normal Freezing Point of water = 0°C => temperature at which substance changes to the solid phase)

8. Above 0°C - Molecules have enough kinetic energy to "get away" from each other and flow.
(Normal Melting Point of water = 0°C => temperature at which substance changes to the liquid phase)

9. Above 100°C - Average kinetic energy is so high the molecules are able to "escape" from each other to fill the entire space available to them.
(Normal Boiling Point of water = 100°C => temperature at which substance changes to the gas phase)

10. Chemical Bonding (Intramolecular Forces) vs. Intermolecular Forces
Ionic Bonding - transfer of electrons
Covalent Bonding - sharing of electrons
Metallic Bonding
- metallic substances share their valence electrons among
themselves in a "sea of electrons“

11. Intermolecular Forces
- forces of attraction between neighboring molecules.
Intermolecular Forces are important in determining the
physical properties of substances
– ie. melting point, boiling point, solubility

12. Compared to the strength of intramolecular forces,
intermolecular forces are substantially weaker.
For example, it takes 463 kilojoules to break one mole of O-H bonds, but only
6 kilojoules to melt a mole of ice into water and
41 kilojoules to convert a mole of water to steam.

13. Types of Intermolecular Forces
The boiling point and the melting point of a substance depend on the strength of the intermolecular forces.
The stronger the attractive force the higher the boiling point and the melting point temperature.

14. Properties of Liquids p390
The physical properties of liquids are determined by the nature and strength of the intermolecular forces present between their molecules.

15. the greater the viscosity.
Viscosity - the friction or resistance to motion that exists between molecules of a liquid when moving past each other.
The stronger the intermolecular attraction between
molecules of a liquid,
The greater the resistance to flow →
the greater the viscosity.
Viscosity increases as temperature decreases.
At lower temperatures the speed of the molecules decreases.

16. Properties of CRYSTALLINE SOLIDS p396-399
Particles in the solid state,
(which may be atoms, molecules or ions)
– are not free to move away from each other.
CRYSTALLINE SOLID - particles exist in a
highly ordered repeating pattern called
the crystal lattice structure.
(geometric structure) see figures 13-4 & 13-5 p399

17. AMORPHOUS SOLIDS – substances that are rigid and appear solid but are not arranged in a crystal lattice structure. They are highly viscous, super-cooled liquids, but are not true solids.
examples – Glass, Plastics
Highly viscous liquids have a high resistance to flow because of strong intermolecular forces.
The physical properties of solids, such as hardness, electrical conductivity, and melting point depend on the
kind of particles that make up the solid and on the strength of the attractive forces between them.
4:38
What is metallic glass? - Ashwini Bharathula
TED Ed 4:43

18. Forces Between Particles Properties Examples
Type of Solid
(type of particles)
Forces Between Particles
Properties
Examples
Metallic (atoms)
 metallic bond
soft to hard, low to high melting point, good conductors of heat & electricity, malleable and ductile 
all metallic elements
– Al, Cu, Na, Ag, Fe….
Molecular
(atoms, molecules)
 hydrogen bond,
dipole-dipole, dispersion
soft, low melting point,
poor conductors of heat & electricity
organic compounds
– CS2, C12H22O11
inorganic compounds
– H2O 
Ionic (positive and negative ions)
 electrostatic attraction
hard, brittle, high melting point, poor conductors of heat & electricity
typical salts
– NaCl, KBr, MgSO4
Network Covalent (atoms)
 covalent bonds
very hard, very high melting point, often poor conductors of heat & electricity
diamond, C; graphite,C; silicon, Si; silicon dioxide, SiO2