1. Classifying Matter
Science 8
Mrs. Marks

3. Based on the Makeup of Matter
Pure Substances
Elements
Compounds
Mixtures

4. Elements Simplest pure substance
Cannot be changed into a simpler substance by heating or chemical process
Atoms are the smallest particle of an element
No two elements contain the same type of atom

5. Compound
Two or more elements chemically combined into a pure substance
The properties of a compound differ from those of the substances from which it is made
Water is a liquid. What elements make up the water?

6. Compound (cont’d)
A compound always contains two or more elements joined in a fixed proportion. (always the same formula)
Can only be separated by electric energy, high heat, or chemical reaction

7. Mixture Two or more substances physically combined
The proportions of the substances can vary, no fixed recipe
The substances can be separated by physical means (using each substance’s physical properties - color, weight, boiling point)

8. Types of Mixtures Homogeneous Heterogeneous
The substances are evenly distributed so that it is difficult to distinguish one substance in the mixture
“Well mixed”
General Examples: air, pudding
Heterogeneous
The parts of the mixture are noticeably different from one another
“slightly mixed”
General Examples: Salad, Dirt

9. Solutions (homogeneous)
When substances dissolve in another substance
The particles in a solution are too small to settle out, be trapped by a filter or scatter light
Tap water
Salt water

10. Parts of Solutions Solute = the material that gets dissolved
Solvent = the substance that makes the solute dissolve
Examples:
Salt Water
(salt= solute), (water=solvent)
Removing nail polish
(polish=solute), (remover=solvent)

11. Alloy – A special Solution
Mixture of 2 or more metals
EXAMPLE: Brass, Bronze

12. Colloids (homogeneous)
Particle size are medium
Colloids do not separate into layers, do not filter out
They can scatter light
Examples:
Milk
Fog
Milk
Fog

13. Suspensions (heterogeneous)
Separates into layer over time
Particles can be filtered out
Cloudy appearance
Examples
Dirty Water
Salad Dressings
Sand water mixture
Muddy water