Phases of Matter

1
Phases of Matter
2

• particles in SOLIDS

• tightly packed in orderly pattern
• particles cant move very much
• only vibrate back forth

3

• particles in GAS
• far apart
• move rapidly from place to place
• they can tumble
• they can shake

4

• particles in liquids
• in between solids gases particles have more
  movement than solids but still close together
• have very hindered movement moving place to
  place, sliding or tumbling
• bump into neighbors

5

• Why do different states of matter exist?
• What is difference between the phases?

6
Kinetic Energy

• atoms molecules in constant motion
• temperature measure average KE of particles in
  sample of matter

7

• if temperature?,
• the average KE?
• if temperature ?,
• then average KE ?

8
Temperature vs. Phase

• all three phases can exist at the same
  temperature
• gas, solid liquid at same temp have same
  average KE
• but

9

• particles in three phases move very differently
  so there must be something else besides energy
  that determines the phase of matter
• there are molecular forces in play!

10
What is a phase change?

• a transition between two different phases
• there are 6 phase changes
• can you name them?

11
freezing (solidification) liquid ? solid
melting solid ? liquid
12
condensation gas ?liquid
vaporization (boiling) liquid ? gas
13
deposition gas ? solid
sublimation solid ? gas
14

• 1. solidification
• or freezing l ? s
• 2. melting s ? l
• 3. vaporation
• or boiling l ? g
• 4. condensation g ? l
• 5. sublimation s ? g
• 6. deposition g ? s

15
Phase Changes

• When substance goes from gas to condensed phase
  (s or l), what happens?
• particles get closer together and their
• motion slows down

G
L
S
16
Phase Changes

• When substance goes from solid to liquid or gas,
  what happens?
• particles move farther apart and their motion
  increases

G
L
S