1. MIXTURES, COMPOUNDS, AND REACTIONS UNIT 2: PART 5- Matter All Around Us Mrs. Kovach’s 8 th Grade Science

2. Purpose: To Understand that elements combine in many ways to form compounds.

3. PURE SUBSTANCE: MATTER THAT HAS THE SAME PROPERTIES AND COMPOSITION THROUGHOUT. (They cannot be separated by physical means such as filtration, distillation, and chromatography) Filtration: separating sand from water Distillation: separating water from ink EXAMPLES: The Element Gold or Aluminum and when different elements combine other substances are formed.

4. The Elements Hydrogen and Oxygen exists as separate colorless gasses but when combined form the compound of water. Compound pure substance whose smallest unit is made up of atoms of more than one element chemically reacting and joining together. (They usually have properties that are different from the elements that make it up. Ex. Hydrogen Peroxide H 2 O 2 is different than the compound for water) Learn360 - SearchLearn360 - Search

5. The reaction of liquid hydrogen and liquid oxygen is what this space shuttle is powered by. It produces a large amount of energy and the compound water.

6. Why would a car that burns hydrogen rather than gasoline be friendly to the environment?

7. The formula tells you which two elements make up the compound as well as how many atoms of each element is present. EXAMPLE: H 2 O tells you that there are 2 Hydrogen and 1 Oxygen and there are 2 atoms of Hydrogen and 1 atom of Oxygen. It will always stay the same compound no matter how many you use of this combination. You can have 12 atoms of Hydrogen and 6 atoms of Oxygen it is still written the same…but you have (6 H2O)

8. Propane has 3 carbon and eight hydrogen atoms. What is its chemical formula? C3H8