1. Warm-Up 8/29/16 What are the two classes of matter?
A(n) _______ is made up of only one type of atom.
A(n) ______ contains a fixed ratio of elements.
What are the two types of mixtures?

2. States of Matter

3. States of Matter Plasma: highest energy state.
Gas: No definite volume, no definite shape, least dense
Expands/contracts to fill container
Capable of being compressed
Particles are always in motion
Liquid: Definite volume, no definite shape
Takes the shape of container
Movement is less restricted, particles move around and collide with each other
Solid: Definite volume & shape
Lowest energy state, most dense state (except water)
Very little particle movement

5. Gas Terms Gases: gaseous state at room temp.
Ex: H2, He, CO2, CH4
Vapor: liquid or solid at room temperature.
Ex: Br2
Steam: vapor specific to water.

6. Phase Changes State Changes are Physical Changes
Melting: Solid Liquid
Freezing: Liquid  Solid
Vaporization: Liquid  Gas
Condensation: Gas  Liquid
Sublimation: Solid  Gas
Deposition: Gas  Solid
State Changes are
Physical Changes

7. Phase Changes

8. Exothermic v. Endothermic
Exothermic: Feels hot, energy exits system. reactions/
Endothermic: Feels cold,
energy enters system.

9. Physical Changes
Physical: A change that does not change the composition of a material, observed or measured property
Intensive Physical Property: Does NOT depend on size of sample.
Ex: Density, boiling point, conductivity
Extensive Physical Property: depends on size of sample.
Ex: mass, volume

10. Chemical Changes
Chemical: substance changes into new substance - composition changes. The substance is no longer the same, different identity (Ex. Burning)
Indicators of a chemical change:
Energy is absorbed/released—temperature change
Change in color
Change in odor
Production of a gas (bubbles, fizzing)

11. Practice

12. Classify each change as either chemical or physical.
Gasoline in your engine burns as you start the car.
Distilled water
Rust on a nail
Glow sticks
Medicine crushed into a powder
Chemical
Physical
physical