1. Classification of Matter
Ch. 15
Ms. Dice
BIG IDEA:
Matter exists as either a pure substance or a mixture.

2. Section 1: Composition of Matter
The bottom of a pail holding ocean water will have sediment that has settled overtime. The water itself, however, will still be salty. Why doesn’t the salt settle with the sediment?

3. A. Substances Matter: anything that takes up space and has mass
Everything around us is made up of matter
Matter is either a pure substance or a mixture of substances
Substance is a type of matter with a fixed composition. A substance can be an element or a compound
Describe the types of substances present in an ice cream soda.

4. 1. Elements
An element is a substance made up of atoms that are all alike.

5. 2. Compounds
Two or more elements can combine to form substances called compounds.
A compound is a substance in which the atoms of two or more elements are chemically combined in a fixed proportion. (example: water)
The elements that make up a compound cannot be separated by physical means.
Compare: How are elements and compounds related?

6. B. Mixtures
A mixture is matter composed of two of more substances that can be separated by physical means.
Two Types:
Heterogeneous mixture
Homogeneous mixture

7. 1. Heterogeneous Mixtures
A mixture in which different materials remain distinct is called a heterogeneous mixture. (example: salad dressing, salad)
Some components are easy to see
Some components you cannot see with the bare eye

8. Types of Heterogeneous Mixtures
1. A suspension is a heterogeneous mixture made of a liquid and solid particles that settle.
2. A colloid is a heterogeneous mixture with particles that never settle.

9. Identifying a Colloid
Tyndall Effect: Scattering of a light beam as it passes through a colloid
This happens because the particles in the colloid are big enough to scatter light, but those in a solution are not.

10. 2. Homogeneous Mixture
A homogeneous Mixture is a mixture that remains constantly and uniformly mixed and has particles that are so small that they cannot be seen with a microscope.
Due to the interaction between the particles, they will never settle to the bottom of a container.
A solution is the same thing as a homogeneous mixture. (Examples: Tea, Vinegar, compressed gas used by divers.)

11. Matter Pure Substances Mixtures Homogeneous Heterogenous Compounds
Elements
Ex: Oxygen, Gold, Iron
Salt, baking soda, sugar
Ex: Lemonade, Gasoline, Steel
Ex: Dirt, Blood, Milk
Fill in the Blanks on this chart using your notes!

12. HOMEWORK
Section 1: Answer Questions 1-4 in your notes