1. Section 1 Classification of Matter
Chapter 18
Section 1
Classification of Matter

2. Two Ways to Classify Matter
Matter can be classified as either a pure substance or a mixture.
A pure substance is a material that cannot be broken down without changing its properties.

3. Three Pure Substances #1 Elements
Elements: a substance made of the same type of atom (see p. 591 for periodic table)
Elements cannot be broken down further without losing that element’s properties.
Examples of elements:
Oxygen, He, Carbon, H

4. Americium
Gold
Aluminum
Tungsten
Titanium
Lead

5. Three Pure Substances #2 Compounds
Compounds: Two or more different elements combined. Properties of a compound may be very different than the elements in it (i.e. NaCl)
Examples of compounds:
C6H12O6,, NaCl, CO2,

6. Three Pure Substances #3 Molecule
Molecules: Two or more atoms combined. This means all compounds are molecules, but not all molecules are compounds.
Examples of molecules:
O2, H2, , CO2, C6H12O6,,

7. Classify Each as Element or Compound
Iron
HCl (hydrochloric acid)
Silver
H2O (water)
Calcium
Neon
CO (carbon monoxide)

8. Mixtures
Another way to classify matter is a mixture. A mixture is a blending of two or more materials that do not form compounds. They can be easily separated. There are two types of mixtures.
Homogeneous mixtures: these have an evenly mixed uniform composition
Heterogeneous mixtures: an uneven, non-uniform composition

9. Homogeneous Mixtures One type of homogeneous mixture is a solution.
A solution is when one substance is dissolved into another. Solutions often appear to NOT look like mixtures.
The item that is dissolved is called the solute. The material that the solute dissolves into is called the solvent.

10. Solution Examples Salt water Vinegar Lemonade Earth’s atmosphere
Kool Aid
Alloys

11. Heterogeneous Mixtures
One type of heterogeneous mixture is a suspension.
Suspension: two or more ingredients combined with very visible particles.
In a liquid suspension, sometimes these particles will separate when left standing
Suspensions can be separated using a filter.

12. Examples of Suspensions
Italian dressing
Muddy water
Chicken soup

13. Colloids
A colloid is a mixture that falls between homogeneous and heterogeneous.
Colloids can appear transparent, cloudy, or opaque. Particles that make up colloids can be similar to solutions.
Colloids cannot be separated with a filter.
Tyndall Effect: when passing a light through a colloid, it will scatter the light.

14. Examples of Colloids
Fog
Smoke
Milk
Hair Gel
Shampoo

15. Ch 18.1 Matter Analysis-Date__ Name________________ Hr__
Copy & answer using sentences. Show work.
Explain differences: element & mixture
Explain differences: compound & mixture
Explain differences: colloid & suspension
Why do words “shake well before using” tell that something is a suspension?
A fabric mixture has 10% polyester+90% cotton. How many g cotton in 500 g fabric?

16. Properties of Matter
Chapter 18 Section 2

17. Physical Properties
Physical Properties: property that can be observed without changing the identity of a material
Examples: Density, melting point, boiling point, ductility, magnetism, shape, odor

18. Chemical Properties
Chemical Property: property that would change the identity of a material while observed
Examples: Flammability, oxidation, pH

20. Chemical Changes vs. Physical Changes
A chemical change is when a new substance forms and the old is altered.
A physical change is when a substance changes size, shape, or state of matter.

21. Classifying chemical changes
Look for these pieces of proof for chemical change:
Smoke
Bubbles
Accidental change in color
Formation of heat (EXOTHERMIC reaction)
Sudden lower temp. (ENDOTHERMIC reaction)
Odd odors

22. Classifying Physical Changes
Remember, the original material is still there! Look for the following:
Melting
Evaporating/Boiling
Freezing
Condensation
Any changes in size!

23. Classify the following changes:
Crack an egg
Fry an egg
Bend a spoon
Bleach on clothing
Baking cookies
Rust on metal
Tarnish on a silver spoon
Getting a haircut
Leaves turning red in the fall
Gasoline burning

24. Law of Conservation of Mass
In any type of change, the total amount of mass NEVER changes.

25. Mass Conservation Example
With chemical reactions, total mass of reactants equals total mass of products.
If 18 g of hydrogen completely reacts with 633 g of chlorine, how many grams of HCl are formed? H2 + Cl2 = 2HCl
Solve for HCl : ? g H2 + ? g Cl2 = ? g HCl
Substitute values: 18g + 633g = 651 g HCl

26. Ch 18.2 Matter Analysis-Date__ Name________________ Hr__
Copy & answer using sentences. Show work.
Why is evaporation a physical change?
List 4 physical properties for a liquid.
Why is flammability a chemical property?
Explain Law of Conservation of Mass for chemical changes like burning wood.
If g of Bi react completely with 200 g of F, how many g of BiF3 form?