1. Daily Science February 18
List two properties of a solid, liquid, and gas
Explain why you were able to put more drops of water on the penny than you thought.
What is capillary action? Give an example.
Give an example of diffusion.

2. Phase Changes
Pg. 91

3. Phase changes that require energy
Melting- particles are speeding up
Melting point- point at which solids turn to liquids. Same as freezing point.
Vaporization-liquid changes to a gas
When it occurs only at the surface-evaporation
Vapor exerts pressure over a liquid (vapor pressure)
Boiling point- when vapor pressure = atmospheric pressure
Sublimation
Solid changes directly to a gas

4. Phase changes that release energy
Condensation
Gas becomes liquid
Happens when particles cool
Freezing
Liquid to solid
Temp at which occurs called freezing point
Deposition
Gas to solid

5. Key:
Endothermic
Exothermic
Gas
Liquid
Solid

6. Phase diagrams Phase diagram- graph of pressure versus temp
T and P have opposite effects
Can predict what phase a substance will be in
Triple point- represents the temp and pressure where that substance can exist in all three phases
Critical point- temperature at which the substance can not exist as a liquid
Lines represent points where substance can exist in 2 phases
Can determine the melting point and boiling point by determine the temp at the phase change at 1 atm

7. Critical point

8. Boiling point and freezing point graphs
During a phase change, the temperature does not increase
You see a horizontal line during a phase change
A positive slope represents a state of matter