Warm Up – 9/18

1. What are the types of pure substances?

2. What is the difference between an element and a compound?

2.3 Mixtures UNIT 2 Matter and Change

Mixtures vs. CompoundsAll Matter

Pure Substance

Element Compound

Mixture- Made up of only 1

kind of matter- Has uniform and definite composition

- simplest

form- cannot

be divided

- 2 or more different elements

chemically combined

- 2 or more pure substances physically blended together

Element Compound

Mixture

Compounds vs Mixtures

1. Create a new form of matter with unique properties

2. Fixed/definite compositionEx: Aspirin is always 60% Carbon, 35.5% Oxygen and 4.5% Hydrogen.

3. Can only be separated be a chemical change Color, size, solubility, odor,

density, freezing, melting, or boiling points

1. Combine properties of its parts Ex: Red + White = pink

2. Ratio between parts can varyEx: Concrete may be 90% sand or 85% or even 1%

3. Can be separated by physical properties

Mixtures vs. CompoundsAll Matter

Pure Substance

Element

Compound

Mixture

Homogenous

Heterogenous

Homogeneous Mixtures have a uniform composition throughout

Ex: gasoline, syrup, air and metal alloys like gold, steel or brass

Homogeneous mixtures are also called solutions

Heterogeneous Mixtures are not uniform in composition

Ex: orange juice, chocolate chip cookies, lucky charms, Italian dressing, salads

Homogeneous or Heterogeneous?

Phases A uniform part with the same

properties Since Homogeneous mixtures are

uniform throughout they only have 1 part or phase

Heterogeneous mixtures have 2 or more distinct parts or phases

For separating liquids… use DISTILLATION

For separating liquids from solids…use FILTRATION

PracticePure Substance or Mixture? 1. Air 2. cobalt 3. Carbon Dioxide 4. Salt water 5. granite 6. Raisin Bran cereal

PracticeHomogeneous or Heterogeneous? 1. Blood 2. Apple 3. Oil and water 4. Raisin Bran 5. Granite 6. Tea