1. Classifying Matter

2. Matter
Pure Substance
-definite composition -cannot be physically separated
Element
-one type of atom
Compound
-two or more types of atoms chemically bonded
Mixture
-two or more varying parts -can be physically separated
Homogeneous
-evenly distributed -uniform properties
Solution
-very small particles
-light passes through
Heterogeneous
-unevenly distributed -varying composition
Suspension
-large visible particles
-particles settle out
-blocks light
Colloid
-unevenly suspended particles
-shows a visible beam of light (positive Tyndall Effect)

3. How do you classify matter?
If it is a pure substance:
There is a fixed composition
There is a chemical formula
If it is a mixture:
There is a varying composition
It is combined physically
It can be separated physically

4. How do you know if something is an element?
The chemical formula shows only one type of atom
How do you know if something is a compound?
The chemical formula shows two or more elements combined

5. Homogeneous OR Heterogeneous?
Homogenous mixture
– composition of the mixture is the same throughout.
Examples: soda, KoolAid
Heterogeneous mixture
– composition is unevenly distributed throughout.
Examples: cookie dough ice cream, iron filings in sand

6. Tyndall Effect
Scattering of light beam caused by the reflection from suspended particle
If the light passes through the mixture with no visible beam, then the mixture is a SOLUTION
If a mixture settles out and blocks the light, then it is a SUSPENSION
If a mixture does not settle and shows a beam of light through it (positive tyndall effect), then it is a COLLOID

7. How do you know if it is a Solution?
Uniformly Mixed
One substance is dissolved in another
solute: part of the mixture that gets dissolved
solvent: part of the mixture that does the dissolving
Tyndall Effect:

8. How do you know if it is a Suspension?
Particles settle out
Tyndall Effect:

9. How do you know if it is a Colloid?
Particles unevenly distributed throughout
Shows a beam of light
Tyndall Effect:

10. Hom/Het? Soln/Susp/Coll?
Fog ____________ ___________
Paint ____________ _________
Syrup ____________ ___________
Colloid: yogurt

11. Particle View of Matter

12. Draw particles on note sheet.

13. Examples