1. COMPOUNDS
Chapter 5 - 2

2. Compounds: Made of Elements
A compound is a pure substance composed of two or more elements that are chemically combined.

3. CHEMICAL REACTIONS FORM COMPOUNDS
A chemical reaction is the process by which substances change into new substances.
The atoms are rearranged into new combinations.

4. Properties of Compounds
Each compound has its own physical properties like melting point, density, and color.
They can also be identified by their different chemical properties, such as reaction to acid and oxygen.

5. Properties: Compounds vs. Elements
A compound has properties that are different than the elements that form them.

6. Ratio of Elements
Elements combine in a definite ratio to form a compound.
Examples: H2O, CO2, HCl, NaCl

7. Breaking Down Compounds
Some compounds can be broken down into their elements by chemical changes.
Opening a carbonated drink lets the carbonic acid break down into simpler compounds-
carbon dioxide
and water

8. Methods of Breaking Down Compounds
The only way to break down a compound is through a chemical change.
Sometimes energy needs to be added for a chemical change to happen.
Examples: apply heat or apply an electrical current.

9. Compounds in Industry
Compounds found in nature are not usually the raw materials needed by industry.
These compounds must be broken down to provide the raw materials.
Example: aluminum oxide

10. Compounds in Nature Proteins are compounds found in all living things.
Carbon dioxide is another compound that is used in photosynthesis.

11. THE END OF CHAPTER 5 - 2