1. Kinetic Energy Attractions vs. Unit 11: States of Matter
GAS
LIQUID
SOLID
main difference between phases is…
the distance between particles…
…which depends on two competing factors:
Kinetic Energy
(Kinetic Energy of the particles)
Attractions
(Attractions between particles)
vs.

2. ↑Temp ↑KEavg K = oC + 273 no KE Kinetic Molecular Theory as
average KE of particles is directly proportional to temperature
373 K
273 K
K = oC + 273
no KE
0 K
absolute zero
–273oC
–460oF

3. flows expands compressible
SOLID
LIQUID
GAS
video clip
low KE, vibrates
higher KE,
flows
highest KE,
expands
VLC – media file (Changes of State)
compressible

4. GAS SOLID LIQUID Phase Changes condensation sublimation deposition
Energy Absorbed
Energy Released
GAS
condensation
sublimation
deposition
vaporization
Video – Changes of State
melting
SOLID
LIQUID
freezing

5. liquid solid + energy liquid solid + energy
freezing:
l to s (lose KE)
liquid solid + energy
lose KE
gain KE
Forces of attraction between molecules cause them to get closer, then vibrate about fixed positions and form a solid.
liquid solid + energy
melting:
s to l (gain KE)

6. energy + liquid gas vaporization: g to l (gain KE) evaporation:
l to g at surface
boiling:
l to g beneath surface

7. gas liquid + energy condensation: g to l (lose KE)
warm water vapor in air
ice cubes
cold water inside glass
condensed drops outside glass
Is water in glass cooler or warmer ?

8. Quick Quiz!
1) The average kinetic energy of the particles in a substance is directly proportional to the
A) molar mass
B) density
C) temperature
D) size 8

9. A) attract each other significantly B) are spaced relatively far apart
Quick Quiz.
2) Compared to liquids and solids, gases are easily compressed because the particles in a gas…
A) attract each other significantly
B) are spaced relatively far apart
C) are extremely small
D) move in constant, random motion 9

10. Quick Quiz.
3) What is –88oC in Kelvin temperature?
A) 185 K
B) 361 K
C) –361 K
D) 273 K
K = oC + 273
K = – 10

11. Quick Quiz.
4) Put a cup of water on a table. The process that occurs is…
A) evaporation.
B) condensation.
C) BOTH A and B
D) NONE of the above