1. Warm up 10/20/15 Which of the following describes a liquid?
The particles are far apart and moving fast.
The particles are close together but moving past each other.
The particles are far apart and moving slowly.
The particles are close together and vibrate in place.
Boiling points and freezing points are examples of…
physical properties.
chemical properties.
energy.
matter.

2. 3.2 Changes of State

3. Temperature
Temperature is a measure of the speed of the particles in a substance
Gases have the fastest moving particles (highest temperature), and solids have the slowest moving particles (lowest temperature)

4. Exothermic vs endothermic
An exothermic process is one where energy is released.
An endothermic process is one where energy is absorbed.

5. Change of state
Changes of state may occur when a substance gains energy (increases in temperature) or loses energy (decreases in temperature).

6. Melting/Freezing Point
Changes of State
Gas
Boiling Point
Particles moving faster
Gaining energy
(Endothermic)
Particles moving slower
Losing energy
(Exothermic)
Liquid
Melting/Freezing Point
Solid

7. Changes of state Melting – solid to liquid Freezing – liquid to solid
Vaporization – liquid to gas
Condensation – gas to liquid
Sublimation – solid to gas
Deposition – gas to solid

8. All changes in state require a change in energy
Changes in States (Physical Changes)
Why do you think Bose-Einstein and plasma are not equally distanced from the other three states of matter?
Plasma
Deposition
Vaporization
(Evaporation/Boiling)
Gas
Melting
Liquid
Condensation
Solid
Freezing
Sublimation
Bose-Einstein
All changes in state require a change in energy

9. Boiling vs Evaporation
Vaporization can occur through evaporation or through boiling.
Evaporation occurs only at the surface of the liquid
Boiling occurs throughout the liquid

10. Sublimation Sublimation occurs when a solid turns directly into a gas.
Dry ice is one of the best known substances that undergoes sublimation. When the solid heats up, it turns directly into a gas (no melting = “dry” ice).

11. Review questions What is an exothermic process?
What does the temperature of a substance tell you about its particles?
What is the change of state called where a solid turns into a liquid?

12. Warm up 10/20/15 (w/3.2 notes)
During which change of state do the atoms or molecules slow down?
Boiling
Melting
Condensation
Sublimation
Which change of state is exothermic?
Evaporation
Freezing