1. What are changes of state?
Aim:
What are changes of state?

2. Explain how thermal energy is involved in changes of state
Objectives
Explain how thermal energy is involved in changes of state

3. Evaporation, melting point, freezing, vaporization,
Vocabulary
thermal energy,
Evaporation, melting point,
freezing, vaporization,
change of state, condensation,
phase change

4. What happens to the heat?
What happens if you leave an ice cube in a glass at room temperature?
How can you change the water back to ice ?
What happens to the heat?

5. Investigate:
Have students investigate what happens when they breathe on a mirror held at different distances.
Why does this happen?

6. OBSERVE water evaporating and boiling:
Investigate:
OBSERVE water evaporating and boiling:
How are boiling and evaporation different?

7. What solids melt at VERY high temperatures.
Investigate:
What solids melt at VERY high temperatures.

8. Particles of a substance are called _____ ?
Molecules

9. What are the three phases of matter?
Solid, Liquid, Gas

10. What is the difference in the molecules of a solid, liquid, and gas?

11. What is the state of matter? Describe the vibration of molecules!

15. Which particles have more heat?

16. Which would hurt more, hot water or cold water?
Since warmer particles have more heat, which state do you think has more energy?
Which would hurt more, hot water or cold water?

17. THERMAL ENERGY is heat energy
THERMAL ENERGY is the energy of the moving particles of a substance.

18. Thermal energy flows from warmer substance to a cooler substance
So when you put something in the Freezer – it looses its heat
The water does not gain cold!

19. Which state has more thermal energy: a gas or a solid?
When thermal energy flows from one direction to another it is called heat

20. As a substance gains or looses heat,
It may change state from a
solid>liquid>gas
gas>liquid>solid

21. Vibrates in a fixed position More thermal energy
SOLID
Least thermal energy
Vibrates in a fixed position
LIQUID
More thermal energy
Vibrates a little more
Shape of container
GAS
Most thermal energy
Vibrates most
Shape of container if sealed

22. Changes b/t Solid & Liquid
MELTING
solid to liquid
As the ice gains energy – more molecules vibrate
eventually the bonds that form the ice crystals break and the ice melts.
FREEZING
the reverse: looses thermal energy
The molecule move about more slowly
Eventually the ice crystal start to form

23. Changes b/t Solid & Liquid
MELTING
solid to liquid
As the ice gains energy – more molecules vibrate
eventually the bonds that form the ice crystals break and the ice melts.
FREEZING
the reverse: looses thermal energy
The molecule move about more slowly
Eventually the ice crystal start to form

24. Changes between a liquid and a gas

25. Reverse of Vaporization is called CONDENSATION
EVAPORATION
Water slowly gains energy
Gradually converts to gas
“sweating”
BOILING
Water rapidly gains energy
Quickly converts to gas
Reverse of Vaporization is called CONDENSATION

26. SOLID > GAS
SUBLIMATION
Dry Ice

27. Evaporation, melting point, freezing, vaporization,
Summary
thermal energy,
Evaporation, melting point,
freezing, vaporization,
change of state, condensation,
phase change
REVIEW VOCABULARY –

28. AIM: What are habitats and niches?
Class Activity:
Worksheets Concept 12-2

29. AIM: What are habitats and niches?
Homework:
INTERNET QUESTIONS
Paragraph