1. Notes: 13.1 and 13.3 OBJECTIVES: Students will be able to (SWBAT)
Explain how intermolecular forces affect states of matter
QUESTIONS TO PONDER:
How does the kinetic molecular theory affect atoms and molecules?
How are the actions of particles different between gases, liquids and solids?
Which interactions or forces would most likely be found in each type of state (gas, liquid and solid)?
How is viscosity and surface tension affected by IMFs?
How do the 4 types of solids differ in their interactions?

2. Gases (13.1)
Kinetic molecular theory explains gas behavior, especially in motion
Kinetic energy is energy of motion
Particles are always in motion

3. Properties of Gases Particles are spaced far apart (low density)
Particles have low attraction to each other
Have fluidity (ability to flow)
Are compressible (can be squeezed)
Have fastest and most random motion

4. Moving gas particles…

5. Compression and Expansion
movable pistons
gas cylinders

6. Diffusion Gas particles move to be evenly distributed
Particles diffuse because of random motion

7. Heat affects motion Heat (energy) increases kinetic energy
Warmer  particles moving faster
Cooler  particles moving slower

9. Liquids and Solids (13.3) Review: 3 States of Matter
solid, liquid and gas

10. Just add (or take away heat)… Which state has the strongest intermolecular attractions?
REMOVE HEAT

11. States of Matter and Intermolecular Forces (IMFs)
Stronger the IMF  particles will be more compacted (close together)
Strongest  solids
ionic bonds
covalent network bonds
At very low temperatures, most substances can be solids
Liquids
mostly polar (dipole-dipole) interactions
Heavy, non-polar molecules
Weakest  gases
nonpolar molecules
If temperature is high enough, most can be gases

12. Properties of Liquids Liquids Denser than gases (more compact)
Ability to flow

13. Viscosity Resistance of a liquid to flow because of IMFs
High viscosity  thick  flows more slowly
Honey, syrup
Low viscosity  more “liquidy”  flows more rapidly
Water, many other liquids
As temperature increases, viscosity will decrease (flows faster)  less IMF because particles are farther apart

15. Surface Tension
Surface of liquid sticking together (cohesiveness) due to IMFs
The reason why drops of liquid form
molecules at or near the surface tend to contract the surface into smallest possible area

17. Properties of Solids Solids
Densest state (particles packed close together)
Not very compressible (hard to squeeze further)
Solid particles do move  they vibrate in place

18. Types of Solids: Crystals
crystalline solids: particles arranged in a geometric, 3-D structure
Ionic crystals: ions in lattice structure (salts)
Molecular crystals: molecules in lattice structure (ice  any molecule if cold enough)
Metallic solids: metal atoms held together by metallic bonds in a sea of electrons (any solid metals)
Covalent network solids: nonmetal atoms held together in repeating pattern by covalent bonds which are very strong (diamonds)

19. Types of Solids: Crystals
crystalline solids: particles arranged in a geometric, 3-D structure
BOND TYPE
DESCRIPTION
INTER or INTRA
IONIC
Ions form lattice structure  salts
METALLIC
Metal atoms held by “sea of electrons”
COVALENT
Non-metal elements held tightly by covalent bonds (e.g. diamonds)
BETWEEN COVALENT MOLECULES
Distinct (separate) molecules held together by IMFs (dipole-dipole, London, H-bond)

20. Types of Solids: Crystals
crystalline solids: particles arranged in a geometric, 3-D structure
BOND TYPE
DESCRIPTION
INTER or INTRA
IONIC
Ions form lattice structure  salts
INTRA
METALLIC
Metal atoms held by “sea of electrons”
COVALENT
Non-metal elements held tightly by covalent bonds (e.g. diamonds)
BETWEEN COVALENT MOLECULES
Distinct (separate) molecules held together by IMFs (dipole-dipole, London, H-bond)
INTER