Teacher Notes
Student Activity Sheet
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Teacher Notes
Teacher Background and Directions: Once the procedure is approved, students move on to carrying out their procedures working in groups of two. Data is recorded in the logbook in an approved data table. Teachers need to make sure that the students have a table like the one below to record their results. Those scoring a “4” will probably have a data table but students scoring below a 4 might not have one prepared.
Then the Data Analysis Questions must be answered. Data Analysis Question One will be evaluated according to the Data Analysis Rubric provided below. One possible problem with the identification of plastic containers is that the containers might contain coloring pigments or other additives to slightly change the density compared to the pellets.
Teacher Preparation: Materials from the Sinkers and Floaters Activity must be provided. Students will need their logbooks containing their teacher approved procedures. NOTE: It is recommended that pellets be used as a reference or guide as students analyze the plastic container pieces.
Rubric: Analyzing Data
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Student Activity Sheet
ELABORATE #7: Can You Use Your Procedure to Identify the Plastics?
Student Activity Sheet Name: _________________________
Your Mission: Use your teacher approved procedure to identify the unknown plastics.
The materials used are the same ones used in Sinkers and Floaters. Data from the experiment should be recorded in the data table in your logbook. When the experiment is complete, clean your laboratory area and then answer the Data Analysis questions listed below. Be sure to use your data in your answers. Record your answers in your logbook. Question One will be scored by the rubric given on the attached student sheet.
Purpose: To identify the unknown plastics.
Materials: 1 small piece of each of your unknown containers from Activity #2. In order to distinguish the plastic pieces, you need to cut each piece into a specific shape. Make a key in your logbook giving the original lettering of that plastic to the shape cut. For example: Plastic A is a rectangle; B, a square; C, a triangle; D, a rectangle with a notch; E, a square with a notch, etc. Record the shapes and plastic letter in the data table. NOTE: It is recommended that pellets be used as a reference or guide as you analyze the container pieces.
- 3 - 8 oz clear cups
- 60 mL 70% isopropyl alcohol
- 60 mL concentrated calcium chloride solution
- 60 mL distilled water
- 1 pipet, plastic spoon or eye dropper
- scissors
- goggles
- 3 craft sticks
- 12 pellets – 2 of each kind
Procedure: Follow the teacher approved procedure in your logbook.
Data Analysis: Can you use the data gathered in your investigation to answer the following questions?
- Were the containers as easy to identify as the resins using the flow chart? Explain. (This question will be evaluated according to the Data Analysis rubric.)
- Which kinds of plastics are now easy for you to identify by just using your senses?
- Go back to the data table for “Can You Classify Plastic Containers? (Activity #2) and find how many of those containers were placed in a group with others of the same code. Fill in the chart below:
- Explain the numbers you got for the last column in this table. How can you account for the high or low fractions?
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