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
low KE, vibrates
higher KE,
flows
highest KE,
expands
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: l to g (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