Biodegradable

Darryl Matthew Bonaparte       Stockton Elementary
                               4420 N. Beacon Street
                               Chicago IL 60640
                               (773) 534-2524

Objectives:

The fifth grade students will be able to
          a. define the meaning of biodegradable        
          b. identify the three types of biodegradables
          c. demonstrate the uses of the three types of biodegradables

Materials Needed:
                               
five pennies           two glass jars or bottles        vitamin c 
small glass plate      two boxes                        1 newspaper
vinegar                masking tape                     hand lens
paper towels           1/3 cup of molasses              1 tsp. yeast
polystyrene foam       1 apple                          scissors
peanut foam            water                            automobile
two small bowls

Strategy:

Description:
Students will investigate and examine biodegradable materials for the purpose of
understanding how to choose the best materials for packing fragile items.

Students will understand how materials break down in the environment through 
experimentations.

Activity 1:
Take a paper towel and fold it in half.  Fold the paper towel in half again
until you have a square.  Soak the paper towel in vinegar.  Put paper towel on
a plate.  Place five pennies on the soaked paper towel and let it sit for
24 hours. 

Teacher will ask students to give their reasons for the change in color of the
pennies.  (After 24 hours, the pennies will have turned green due to the 
chemical reactions from combining the acetate (vinegar) and the copper from the 
pennies which will actually cause the break down of the pennies.) 

Activity 2:
Take newspaper and set it in a place where it can be exposed to sun light for
five days.  (Works best in an automobile.)

Teacher will ask students to respond to questions after observing a newspaper
that has a dull change in its color.  (This change is called photodegradation.)

Activity 3:
Take the peanut and polystyrene foam and cut both into halves.  
Pass the foam around to the students and have them observe the open/closed-cells
in each using a hand lens.  Teacher will ask questions and have students respond
to which foam will break down first when submerged in water  Polystyrene foams 
have a closed-cell structure which not break down in water.  The peanut foams 
have an open-cell structure which will break down in water.  (This change is 
called chemical degradation.)
 
Teacher will generate a discussion about packing materials to use to protect
fragile items.  Students are to decide which packing material is more useful for 
fragile items and will justify their answers.  Teacher will ask two students
to fill a box with the foam packing materials, place a jar or bottle inside the 
box, and seal the box with masking tape.  The two students will decide on the 
height to drop both boxes to find out if the packing materials will protect the 
glass jars from breaking.  (Both boxes must be dropped from the same height.) 
Students are to try again from a different height. 

Teacher will ask students to tell what they noticed from both boxes being 
dropped.  (If jars were packed well in the packing materials, neither jar will 
break.)  Students are to conclude that both foam packing material will protect 
the fragile items. 

Teacher will ask students to discuss the pros and cons of using the foam 
packing materials such as, what would happen to the box if it got wet from the 
rain?  How effective is the foam material when being recycled?

Activity 3:
Teacher will pour into a glass 1/3 cup of molasses and 1 tsp. of yeast into a 
glass jar or plastic cup.  Students are to observe what chemical reaction should 
occur from the mixture of the two and respond or record their answer.
Students should notice that the yeast will bubble on the surface of the molasses
causing a break down of the sugar in the syrup.  Students will observe a 
chemical degradation.  

Activity 4:
Teacher will cut an apple in half, sprinkle vitamin C on the apple, and let the
apple sit for one hour.

Teacher will ask students questions about what they observed of the apple   
after it has sat for an hour.  Students should have recognized that when 
vitamin C is sprinkled on fruit, it counter-reacts the enzymes in the fruit 
from turning yellow or brown.

Assessment:

Students will recall the three types of the degrading process and will give an
  example of each type. 
Students will create a chart for each experiment and record their data.
  (Their data must explain the steps for each experiment.)
Students will conduct each experiment individually or in groups. 
Students will give reasons whether the experiment worked or did not work.
Students will think of other materials that degrade (photo, enzymatic or 
  chemical) and will conduct their own experiment to demonstrate before the 
  class.