May be used as lesson plan or independent student project
This activity makes a great intermediate-level science fair project because it precisely measures volume and the mass of paper and plastic pieces.
- plastic bags
- paper bags
- 50mL Pyrex® beaker (or equivalent)
- triple-beam balance
- two large, heavy marbles
- two cardboard circles that fit inside the 50mL beakers
- To set the stage for this activity, ask your students the following questions: (a.) What do you suppose environmentally conscious consumers might ask before choosing plastic or paper bags at the grocery store?
(b.) Which is easier to transport – plastic or glass soda bottles? Why?
(c.) After emptying items from either a plastic or paper bag, what happens to the bag?
(d.) Why do you think people throw away materials that could easily be recycled?
(e.) Why are landfills filling up at a rapid rate?
(f.) Why does it take a long time for buried trash to decompose in landfills?
- Cut a standard-size paper grocery bag and a standard-size plastic bag with scissors so that both are 12 inches x 12 inches (30 cm x 30 cm). Then, cut them into one-inch (2.5 cm) squares. (The students should end up with 144 paper squares and 144 plastic squares.)
- Place and pack the paper squares firmly into a 50 ml Pyrex beaker. Place and pack the plastic squares firmly into the other 50 ml Pyrex beaker. To help pack the squares, cut out a cardboard circle that fits inside the beakers. Use a large, heavy marble to press the squares to the bottom of the beakers.
- Record in the Data Table the number of milliliters of space occupied by the paper squares.
- Remove and weigh the paper squares together. Record the mass of the paper in the Data Table.
- Repeat steps 2 – 5 with the one-inch plastic squares.
- Which is heavier, the plastic or paper bags? How much heavier?
- Which takes up more space, the plastic or the paper bags? How much more space?
- If landfill space were the only consideration, would it be more environmentally correct to package your groceries in paper or plastic? Why?
- If fuel conservation were the only consideration, would it be more environmentally correct to package your groceries in paper or plastic? Why?
- How much space did the paper bags occupy in cubic centimeters? How much space did the plastic bags occupy in cubic centimeters?
Source: Activity on Paper or Plastic by John Cowens.