1. Changes of State
Ch. 2.2

2. Changes of State Why does Ice Cream Melt?
Ice cream melts because it takes in _thermal_ _energy_ from the air and your hand.
Ice Cream Melting (1:15)

3. Changes Between Solids and Liquids
A. Which state of matter of the same substance has the most thermal energy?
Gas
1. Which has the least?
Solid
States of Matter (4:38)

4. Solids and Liquids B. Melting = change in state from a
_solid_ to a _liquid_
1. Melting point = _temperature_ at which a solid changes to a liquid
2. At its melting point, the particles of a _solid_ are _vibrating_ so fast they break free from their _fixed_ positions.
Brain Pop Matter Changing States

5. Solids and Liquids
C. Freezing = change in state from a liquid to a _solid_
1. Melting point = _Freezing_ point
Bill Nye Water Cycle Clip (2:57)

6. III. Changes Between Liquid and Gas
A. Vaporization = change from a liquid to a _gas_
B. Evaporation = _vaporization_ that takes place only on the _surface_ of liquid
Brain Pop Property Changes

7. Liquid and Gas
C. Boiling = _vaporization_ that takes place on the _surface_ and _below_ in a liquid to change to a _gas_
1. Boiling point = the _temperature_ at which a liquid changes to a gas (boils)

8. Liquid and Gas
D. Condensation = particles in a gas _lose_ thermal energy and form a _liquid_
1. The opposite of vaporization is _condensation_

9. IV. Changes Between Solid and Gas
A. Sublimation = the surface particles of a solid _gain_ enough energy to form a _gas_.
B. During Sublimation, particles of a _solid_ do not pass through the _liquid_ state as they form a _gas_.
1. One example of
Sublimation =
__dry ice__

10. Math (p.52) Temperature and Changes of State
Review the Graph in Your Textbook
Discuss on the Next Slide
Answer Questions 1 – 5 in your Notes!

11. Math (p. 52) Temperature and Changes of State
Review the Graph

12. Questions
1. The 2 variables on the graph are _Time_ and _Temperature_.
2. Segment C shows a rise in temperature from_-_O_°C to _lOO_°C.
3. Segment B represents the _freezing_ or _melting_ _points_ of water.
Segment D represents the _boiling_ _point_ of water.

13. Questions
4. Melting shows a change from a _solid_ to a _liquid_. Boiling shows a change from a _liquid_ to a _gas_.
5. Water molecules in _E_ have more thermal energy because they are at a _higher_ temperature.
Dry Ice Experiment (2:21)