1. Describing the States of Matter
Based their shapes and volumes,
Materials can be classified as:
Solids
Liquids
Gases

2. Solid  Definite shape Definite volume.
Describing the States of Matter
Solid 
Definite shape
Definite volume.
Most solids have orderly arrangement of particles at the atomic level.
Difficult for particles to move past each other.
Example: copper wire

3. Liquid  Definite volume No definite shape.
Describing the States of Matter
Liquid 
Definite volume
No definite shape.
Takes the shape of its container
Can pour from one container to another.
Atoms easily slide past each other, but hard to get away from group
Example:
Mercury atoms are close, but more random than atoms in solid copper.

4. Gas  No definite shape No definite volume.
Describing the States of Matter
Gas 
No definite shape
No definite volume.
Gas takes shape/volume of container.
“Shape” of helium in a balloon is same as shape of the balloon itself.
Volume of helium in a balloon is equal to volume of the balloon.
Particles “fly” past each other, free to move until bump into something.

5. States of Matter
Gas Liquid Solid

6. Solid
Definite volume
Definite shape

7. Liquid
Definite volume
NO definite shape

8. Gas
NO definite volume
NO definite shape

10. Charactaristics of Phase Changes
Materials often undergo physical changes because of temperature and energy changes
Example: freezing = liquid state  solid state
Phase change:
reversible physical change that occurs when a substance changes from one state of matter to another.

11. Charactaristics of Phase Changes
Melting:
solid  liquid
Freezing:
liquid  solid

12. Charactaristics of Phase Changes
Vaporization:
liquid  gas
Condensation:
gas  liquid

13. Charactaristics of Phase Changes
Sublimation:
solid  gas
Deposition:
gas  solid

14. Charactaristics of Phase Changes
Diagram shows physical changes between solid, liquid, and gas phases.
Each arrow shows a different phase change.
All phase changes share certain characteristics related to energy and temperature.

15. Describing the States of Matter
Other States of Matter
PLASMA  atoms break into pieces
Extremely high temperatures (e.g. inside stars), atoms cannot hang on to all their electrons
~99% of all the matter in the universe is in plasmas
State that is not common on Earth
Bose-Einstein condensate
Extremely low temperatures (near –273°C)
Groups of atoms behave as though they are a single particle.

16. Definite or Not? Shape Volume Solid Liquid Gas
Assessment Questions #1
Definite or Not?
Shape
Volume
Solid
Liquid
Gas

17. During a phase change, a substance undergoes a(n)
Assessment Questions
During a phase change, a substance undergoes a(n)
reversible change from one state to another.
irreversible change from one state to another.
reversible change to a different substance.
irreversible change to a different substance.

18. Assessment Questions
What is the phase change in which a solid is converted directly to a liquid?
melting
sublimation
condensation
deposition

19. Assessment Questions
What is the phase change in which a solid is converted directly to a gas?
evaporation
sublimation
condensation
deposition

20. Assessment Questions
What is the phase change in which a gas is converted directly to a liquid?
evaporation
sublimation
condensation
deposition

21. Assessment Questions
What is the phase change in which a gas is converted directly to a solid?
evaporation
sublimation
condensation
deposition

22. Assessment Questions
What is the phase change in which a liquid is converted directly to a solid?
evaporation
freezing
condensation
deposition

23. Assessment Questions
What is the phase change in which a liquid is converted directly to a gas?
evaporation
freezing
condensation
deposition