1. Phases of Matter

2. Phases Review Solid Liquid Gas Plasma Definite shape & volume
Definite volume but can change shape (depends on container)
Gas
No definite shape or volume
Plasma
Ionized gas

3. As an object changes phase, the number of atoms does not change just their arrangement.

4. Temperature
Temperature is the amount of kinetic energy (KE) an object has
The greater the temperature, the more KE, the more the atoms move
All molecules move if their temperature is above 0 K (absolute zero)

5. Objects at the same temperature have the same KE
even though objects have different properties they have same KE at the same temperature.

6. If all molecules have the same kinetic energy at the same temperature, why don’t all things have the same melting and boiling points?
Different molecules have different intermolecular forces acting on them
Stronger the intermolecular force, the higher the melting and boiling points

7. The more KE an object has, the faster the molecules will move (creating disorder).
Entropy = disorder
As temperature increases, entropy increases.
Amount of entropy
Solid < liquid < gas < plasma

9. Kinetic Theory of Gases
Gas molecules are in constant, rapid, straight line motion
(have high temperatures, therefore high amounts of KE)

10. Kinetic Theory of Liquids
When the temperature decreases, kinetic energy decreases.
Molecules move slower.
Molecules slow down enough that molecules are attracted to each other enough to overcome having random, straight line motion
causes molecules to become liquids (molecules can still slide past each other.)

11. Kinetic Theory of Solids
As molecules in a liquid cool, they move more slowly.
Eventually, temperature is reached at which molecules take a fixed position in a regular geometric pattern
Molecules are held at fixed positions by strong intermolecular forces

12. Melting
As temperature increase, molecules vibrate faster and farther apart until the strong intermolecular forces are overcome enough for the molecules to glide past each other
Melting = endothermic.

13. Changes of Phase terms Freezing: liquid  solid
Melting: solid  liquid
Condensation: gas  liquid
Evaporation: liquid  gas
Sublimation: solid  gas
Deposition: gas solid

14. Phase Change Diagram

16. Solutions Solutes impact boiling and melting points
Boiling point is raised when solutes are present
Presence of solutes makes it difficult for water to become a gas
Freezing point is depressed (lowered)
When solute is present in solvent, harder for solvent molecules to make crystal like structure
Do as two labs instead of giving them the answer…have this be an inquiry activity!!!!