1. Compounds and Mixtures Green Book Pages 39-41 and 48-51 Red Book Chp 4 Sect 3

2. Matter Elements Compounds Mixtures

3. Vocabulary  Elements-made up of only one kind of matter  Compound- a pure substance made of two or more elements that are chemically combined  Substance-A sample of matter that has the same composition and properties throughout  Molecules-linked atoms  Chemical Formula- a group of symbols that shows the elements in a compound  Subscript-A number written to the right of and below a symbol in a chemical formula  Mixtures-made up of two or more kinds of matter physically combined but do not combine to form a new, pure substance

4. Subscript  shows how many atoms of an element are present in a single molecule.  If you do not see a subscript in a formula, you can assume that there is ONE atom of that element.

5. H2OH2O  H 2 O is the chemical formula for water.  In a single molecule of water there are 2 hydrogen atoms and 1 oxygen atom.  Water is a compound

6. Is it an ELEMENT or a COMPOUND? Os

7. H 2 SO 4 = ONE molecule of sulfuric acid

8. C 27 H 45 OH = one molecule of cholesterol  How many elements? How many atoms?  What are the names of the elements in the chemical formula?

9. TRY:  C 12 H 22 O 11 = ONE molecule of sugar  C 27 H 45 OH =ONE molecule of cholesterol

10. Mixtures  Made up of two or more kinds or matter physically combined  All the substances in a mixture keep their original properties  Do not use chemical formulas-a single formula could not accurately represent the makeup of a mixture (Composition may vary!)  Can almost always be separated by physical means

11. Examples:

12. Homogeneous Heterogeneous  Examples:

13. Try:  1.How could you separate a mixture of sand and salt? If you added water to the mixture…how might you get the salt back from the salt water?  2.How can mixtures of the same substances differ?

14. Compounds: Mixtures: