A special partnership between the Georgia Department of Education and the Educational Technology Training Centers in support of the 8 th Grade Physical Science Frameworks. Module 3: Food and Cooking

Standards Content S8P1. Students will examine the scientific view of the nature of matter. e. Distinguish between changes in matter as physical (i.e. physical change) or chemical (development of a gas, formation of precipitate, and change in color). g. Identify and demonstrate the Law of Conservation of Matter. Characteristics S8CS2. Students will use standard safety practices for all classroom laboratory and field investigations. a. Follow correct procedures for use of scientific apparatus. b. Demonstrate appropriate techniques in all laboratory situations. c. Follow correct protocol for identifying and reporting safety problems and violations. S8CS4. Students will use tools and instruments for observing, measuring, and manipulating equipment and materials in scientific activities utilizing safe laboratory procedures. a. Use appropriate technology to store and retrieve scientific information in topical, alphabetical, numerical, and keyword files, and create simple files. b. Use appropriate tools and units for measuring objects and/or substances. c. Learn and use standard safety practices when conducting scientific investigations. S8CS6. Students will communicate scientific ideas and activities clearly. c. Organize scientific information in appropriate tables, charts, and graphs, and identify relationships they reveal. S8CS9. Students will understand the features of the process of scientific inquiry. Students will apply the following to inquiry learning practices: a. Investigations are conducted for different reasons, which include exploring new phenomena, confirming previous results, testing how well a theory predicts, and comparing different theories. b. Scientific investigations usually involve collecting evidence, reasoning, devising hypotheses, and formulating explanations to make sense of collected evidence. e. Accurate record keeping, data sharing, and replication of results are essential for maintaining an investigator’s credibility with other scientists and society. f. Scientists use technology and mathematics to enhance the process of scientific inquiry.

Enduring Understandings:  Energy is neither created nor destroyed but can be transformed.  Energy is involved in chemical and physical changes.  As particles are exposed to increasing levels of energy, their speed of movement increases and they will experience a change of phase. Essential Question:  Why do onions make you cry, why do lemons taste sour, and why do sliced apples turn brown after they set in a bowl for awhile?

Pre-Assessment: Identify the physical and chemical changes in each event. Chemical Changes Physical Changes Boiling an Egg Burning a Candle Baking Bread

Pre-Assessment: Identify the physical and chemical changes in each event. Chemical Changes Physical Changes Making Vinegar from Apples Making Cheese, Yogurt or Buttermilk

Pull The baking soda demonstrations can be done using the QX5 digital microscopes or by using a large beaker and a document camera. Heated slowly, the marshmallow will melt (physical change). Heated quickly to a high enough temperature, the sugar will react with oxygen in the air and burst into flame. Teacher Demonstration: Introduce the concept of physical and chemical changes using one of the following demonstrations:  Add water to baking soda  Add vinegar to baking soda  Heat a marshmallow

Station 1: Materials:  test tube in a tube rack  10 mL graduated cylinder  eyedropper  tweezers Directions:  Measure 5 mL of hydrogen peroxide into test tube  Measure the temperature  Use the tweezers to transfer the potato or liver into the test tube  Measure the temperature  Record observations  thermometer  3% hydrogen peroxide  pieces of liver or potato

Station 2: Materials:  apple slices  "Fruit Fresh" or lemon juice Directions:  Compare the treated and untreated apple slices  Record observations

Station 3: CAUTION: HOT SURFACE! Materials:  hot plate  evaporating dish  margarine Directions:  Place a piece of margarine in the evaporating dish  Using tongs, place the dish on the hot plate  Record observations

Station 4: Materials:  10 mL graduated cylinder  test tube in a tube rack  green food coloring  water Directions:  Measure 5 mL of water in test tube  Add 10 drops of green food coloring  Record observations

Station 5: Materials:  10 mL graduated cylinder  test tube in tube rack  green food coloring  dropper bottle of bleach Directions:  Add 5 mL of water to test tube  Add 10 drops of green food coloring  Add 10 drops of bleach  Record observations

Station 6: Materials:  walnuts  scissors Directions:  Use the scissors to cut the nuts into smaller pieces.  Record observations

Station 7: CAUTION: HOT SURFACE! Materials:  hotplate  beaker  water Directions:  Observe the boiling water  Record observations

Station 8: CAUTION: HOT SURFACE! Materials:  hotplate  beaker of boiling water Directions:  Add a dropper of beaten egg white to the beaker of boiling water  Record observations  egg white  eye dropper

Station 10: Materials:  beaker  two 25 mL graduated cylinder  25 mL milk  25 mL vinegar Directions:  Measure 25 mL milk  Pour milk in beaker  Add 25 mL vinegar to beaker  Record observations

Station 11: Materials:  sugar  50 mL graduated cylinder  beaker  water Directions:  Measure 5 g of sugar  Pour water into beaker  Dissolve sugar in 50 mL water  Record observations

Station 12: Materials:  baking soda  vinegar  beaker  25 mL graduated cylinder Directions:  Measure 5 g of baking soda  Add to beaker  Measure 15 mL of vinegar  Add to beaker  Record observations

Station 13: Materials:  egg shell  vinegar  small beaker Directions:  Place small chips of egg shell in small beaker of vinegar  Record observations

Assessment:  Use a digital camera to take a picture of each change  Complete the data chart provided  Arrange pictures into two categories: physical changes and chemical changes  Beside each picture, explain why the change was physical or chemical